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Sample records for dendritic cells pdcs

  1. The relation of plasmacytoid dendritic cells (pDCs) and regulatory T-cells (Tregs) with HPV persistence in HIV-infected and HIV-uninfected women.

    Science.gov (United States)

    Strickler, Howard D; Martinson, Jeffrey; Desai, Seema; Xie, Xianhong; Burk, Robert D; Anastos, Kathryn; Massad, L Stewart; Minkoff, Howard; Xue, Xiaonan; D'Souza, Gypsyamber; Levine, Alexandra M; Colie, Christine; Watts, D Heather; Palefsky, Joel M; Landay, Alan

    2014-02-01

    Other than CD4+ count, the immunologic factors that underlie the relationship of HIV/AIDS with persistent oncogenic HPV (oncHPV) and cervical cancer are not well understood. Plasmacytoid dendritic cells (pDCs) and regulatory T-cells (Tregs) are of particular interest. pDCs have both effector and antigen presenting activity and, in HIV-positive patients, low pDC levels are associated with opportunistic infections. Tregs downregulate immune responses, and are present at high levels in HIV-positives. The current pilot study shows for the first time that low pDC and high Treg levels may be significantly associated with oncHPV persistence in both HIV-positive and HIV-negative women. Larger studies are now warranted.

  2. Neonatal plasmacytoid dendritic cells (pDCs display subset variation but can elicit potent anti-viral innate responses.

    Directory of Open Access Journals (Sweden)

    Xiaoming Zhang

    Full Text Available Neonates are highly susceptible to infectious diseases and defective antiviral pDC immune responses have been proposed to contribute to this phenomenon. Isolated cord blood pDCs innately responded to a variety of TLR7 and TLR9 dependent viruses, including influenza A virus (IAV, human immunodeficiency virus (HIV or herpes-simplex virus (HSV by efficiently producing IFN-α, TNF-α as well as chemokines. Interestingly, following activation by CpGA, but not viruses, cord pDCs tend to survive less efficiently. We found that a hallmark of pDCs in neonates is an extended CD2+pDCs compartment compared to adult pDCs without affecting the antiviral IFN-α response. Within CD2+pDCs, we identified a subpopulation expressing CD5 and responsible for IL-12p40 production, however this population is significantly decreased in cord blood compared to adult blood. Therefore, neonatal pDCs clearly display variation in phenotype and subset composition, but without major consequences for their antiviral responses.

  3. Development of Dendritic Cell System

    Institute of Scientific and Technical Information of China (English)

    Li Wu; Aleksandar Dakic

    2004-01-01

    The dendritic cell system contains conventional dendritic cells (DCs) and plasmacytoid pre-dendritic cells (pDCs). Both DCs and pDCs are bone marrow derived cells. Although the common functions of DCs are antigen-processing and T-lymphocyte activation, they differ in surface markers, migratory patterns, and cytokine output. These differences can determine the fate of the T cells they activate. Several subsets of mature DCs have been described in both mouse and human and the developmental processes of these specialized DC subsets have been studied extensively. The original concept that all DCs were of myeloid origin was questioned by several recent studies, which demonstrated that in addition to the DCs derived from myeloid precursors,some DCs could also be efficiently generated from lymphoid-restricted precursors. Moreover, it has been shown recently that both conventional DCs and pDCs can be generated by the Flt3 expressing hemopoietic progenitors regardless of their myeloid- or lymphoid-origin. These findings suggest an early developmental flexibility of precursors for DCs and pDCs. This review summarizes some recent observations on the development of DC system in both human and mouse.

  4. Development of Dendritic Cell System

    Institute of Scientific and Technical Information of China (English)

    LiWu; AleksandarDakic

    2004-01-01

    The dendritic cell system contains conventional dendritic cells (DCs) and plasmacytoid pre-dendritic cells (pDCs). Both DCs and pDCs are bone marrow derived calls. Although the common functions of DCs are antigen-processing and T-lymphocyte activation, they differ in surface markers, migratory patterns, and cytokine output. These differences can determine the fate of the T cells they activate. Several subsets of mature DCs have been described in both mouse and human and the developmental processes of these specialized DC subsets have been studied extensively. The original concept that all DCs were of myeloid origin was questioned by several recent studies, which demonstrated that in addition to the DCs derived from myeloid precursors, some DCs could also be efficiently generated from lymphoid-restricted precursors. Moreover, it has been shown recently that both conventional DCs and pDCs can be generated by the Fit3 expressing hemopoietic progenitors regardless of their myeloid- or lymphoid-origin. These findings suggest an early developmental flexibility of precursors for DCs and pDCs. This review summarizes some recent observations on the development of DC system in both human and mouse. Cellular & Molecular Immunology. 2004;1(2):112-118.

  5. Plasmacytoid dendritic cell role in cutaneous malignancies.

    Science.gov (United States)

    Saadeh, Dana; Kurban, Mazen; Abbas, Ossama

    2016-07-01

    Plasmacytoid dendritic cells (pDCs) correspond to a specialized dendritic cell population that exhibit plasma cell morphology, express CD4, CD123, HLA-DR, blood-derived dendritic cell antigen-2 (BDCA-2), and Toll-like receptor (TLR)7 and TLR9 within endosomal compartments. Through their production of type I interferons (IFNs) and other pro-inflammatory cytokines, pDCs provide anti-viral resistance and link the innate and adaptive immunity by controlling the function of myeloid DCs, lymphocytes, and natural killer (NK) cells. While lacking from normal skin, pDCs are usually recruited to the skin in several cutaneous pathologies where they appear to be involved in the pathogenesis of several infectious, inflammatory/autoimmune, and neoplastic entities. Among the latter group, pDCs have the potential to induce anti-tumour immunity; however, the complex interaction of pDCs with tumor cells and their micro-environment appears to contribute to immunologic tolerance. In this review, we aim at highlighting the role played by pDCs in cutaneous malignancies with special emphasis on the underlying mechanisms.

  6. Dendritic Cell

    OpenAIRE

    Sevda Söker

    2005-01-01

    Dendritic cells, a member of family of antigen presenting cells, are most effective cells in the primary immune response. Dendritic cells originated from dendron, in mean of tree in the Greek, because of their long and elaborate cytoplasmic branching processes. Dendritic cells constitute approximately 0.1 to 1 percent of the blood’s mononuclear cell. Dendritic cells are widely distributed, and specialized for antigen capture and T cell stimulation. In this article, structures and functions of...

  7. IL-4 and IL-13 alter plasmacytoid dendritic cell responsiveness to CpG DNA and herpes simplex virus-1

    NARCIS (Netherlands)

    Tel, J.; Torensma, R.; Figdor, C.G.; Vries, I.J.M. de

    2011-01-01

    Human plasmacytoid dendritic cells (pDCs) are found in skin lesions in a wide variety of diseases. The role of the microenvironment in these lesions on the function of human pDCs remains elusive. We sought to determine the effect of T(h)2 cytokines on the ability of human pDCs to respond to CpG

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

    NARCIS (Netherlands)

    Mathan, T.S.M.; Figdor, C.G.; Buschow, S.I.

    2013-01-01

    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 presentin

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

    Science.gov (United States)

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

    2017-04-15

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

  10. [Inflammatory dendritic cells].

    Science.gov (United States)

    Segura, Elodie; Amigorena, Sebastian

    2014-01-01

    Dendritic cells are a rare and heterogeneous population of professional antigen-presenting cells. Several murine dendritic cell subpopulations have been identified that differ in their phenotype and functional properties. In the steady state, committed dendritic cell precursors differentiate into lymphoid organ-resident dendritic cells and migratory tissue dendritic cells. During inflammation appears an additional dendritic cell subpopulation that has been termed « inflammatory dendritic cells ». Inflammatory dendritic cells differentiate in situ from monocytes recruited to the site of inflammation. Here, we discuss how mouse inflammatory dendritic cells differ from macrophages and from other dendritic cell populations. Finally, we review recent work on human inflammatory dendritic cells.

  11. Protein Tyrosine Phosphatase PTPRS Is an Inhibitory Receptor on Human and Murine Plasmacytoid Dendritic Cells

    NARCIS (Netherlands)

    Bunin, A.; Sisirak, V.; Ghosh, H.S.; Grajkowska, L.T.; Hou, Z.E.; Miron, M.; Yang, C.; Ceribelli, M.; Uetani, N.; Chaperot, L.; Plumas, J.; Hendriks, W.J.; Tremblay, M.L.; Hacker, H.; Staudt, L.M.; Green, P.H.; Bhagat, G.; Reizis, B.

    2015-01-01

    Plasmacytoid dendritic cells (pDCs) are primary producers of type I interferon (IFN) in response to viruses. The IFN-producing capacity of pDCs is regulated by specific inhibitory receptors, yet none of the known receptors are conserved in evolution. We report that within the human immune system, re

  12. Cutting edge: pulmonary Legionella pneumophila is controlled by plasmacytoid dendritic cells but not type I IFN.

    Science.gov (United States)

    Ang, Desmond K Y; Oates, Clare V L; Schuelein, Ralf; Kelly, Michelle; Sansom, Fiona M; Bourges, Dorothée; Boon, Louis; Hertzog, Paul J; Hartland, Elizabeth L; van Driel, Ian R

    2010-05-15

    Plasmacytoid dendritic cells (pDCs) are well known as the major cell type that secretes type I IFN in response to viral infections. Their role in combating other classes of infectious organisms, including bacteria, and their mechanisms of action are poorly understood. We have found that pDCs play a significant role in the acute response to the intracellular bacterial pathogen Legionella pneumophila. pDCs were rapidly recruited to the lungs of L. pneumophila-infected mice, and depletion of pDCs resulted in increased bacterial load. The ability of pDCs to combat infection did not require type I IFN. This study points to an unappreciated role for pDCs in combating bacterial infections and indicates a novel mechanism of action for this cell type.

  13. Plasmacytoid dendritic cells in antiviral immunity and autoimmunity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Plasmacytoid dendritic cells (pDCs) represent a unique and crucial immune cell population capable of producing large amounts of type I interferons (IFNs) in response to viral infection.The function of pDCs as the professional type I IFN-producing cells is linked to their selective expression of Toll-like receptor 7 (TLR7) and TLR9,which sense viral nucleic acids within the endosomal compartments.Type I IFNs produced by pDCs not only directly inhibit viral replication but also play an essential role in linking the innate and adaptive immune system.The aberrant activation of pDCs by self nucleic acids through TLR signaling and the ongoing production of type I IFNs do occur in some autoimmune diseases.Therefore,pDC may serve as an attractive target for therapeutic manipulations of the immune system to treat viral infectious diseases and autoimmune diseases.

  14. 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.

  15. Natural mannosylation of HIV-1 gp120 imposes no immunoregulatory effects in primary human plasmacytoid dendritic cells

    NARCIS (Netherlands)

    Sondergaard, J.N.; Vinner, L.; Brix, S.

    2014-01-01

    Plasmacytoid dendritic cells (pDCs) play a vital role in activation of anti-HIV-1 immunity, and suppression of pDCs might mitigate immune responses against HIV-1. HIV-1 gp120 high-mannose has been attributed immunosuppressive roles in human myeloid DCs, but no receptors for high-mannose have so far

  16. DNA structures decorated with cathepsin G/secretory leukocyte proteinase inhibitor stimulate IFNI production by plasmacytoid dendritic cells

    DEFF Research Database (Denmark)

    Skrzeczynska-Moncznik, Joanna; Wlodarczyk, Agnieszka; Banas, Magdalena

    2013-01-01

    Plasmacytoid dendritic cells (pDCs) and neutrophils are detected in psoriatic skin lesions and implicated in the pathogenesis of psoriasis. pDCs specialize in the production of type I interferon (IFNI), a cytokine that plays an important role in chronic autoimmune-like inflammation, including pso...

  17. 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

  18. Bruton's tyrosine kinase regulates TLR9 but not TLR7 signaling in human plasmacytoid dendritic cells.

    Science.gov (United States)

    Wang, Jingming; Lau, Kai-Yeung; Jung, Jimmy; Ravindran, Palanikumar; Barrat, Franck J

    2014-04-01

    Plasmacytoid dendritic cells (PDCs) represent a key cell type for both innate and adaptive immunity. PDCs express both TLR7 and TLR9 and the recognition of nucleic acids by these two receptors triggers the production of a large amount of type-I IFN and the induction of PDC maturation into APCs. This unique feature of PDCs is at the basis of clinical development of both TLR7 and TLR9 agonists for infectious diseases, allergy, cancer, and asthma. However, TLR7 and TLR9 recognition of self-nucleic acids is linked to many autoimmune diseases including lupus, and a better understanding of the signaling pathways of these two receptors in PDCs is thus important. We have identified Bruton's tyrosine kinase (Btk) as an important player for TLR9 but not TLR7 signaling in human PDCs. Blocking Btk using a specific inhibitor leads to the reduction of all TLR9-induced responses in PDCs, including cytokine production and expression of costimulatory molecules, while this has no impact on the TLR7 response. This identifies Btk as a key molecule in TLR9 signaling in PDCs and is the first demonstration that the TLR7 and TLR9 pathways can be dissociated in human PDCs. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A novel cell subset:Interferon-producing killer dendritic cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Recent reports introduce a novel cell subset of DCs with antigenic phenotypes shared by both NK cells and B cells, but without surface markers of pDCs and T cells, appearing to be a chimera of NK cells and DCs, namely interferon-producing killer dendritic cells(IKDCs).IKDCs not only secret type I and type II interferons to recognize and kill tumor cells effectively, but also express MHC-II molecules to present antigens.Thus, IKDCs are considered as important immunosurveilance cells for tumors, providing a link between innate and adaptive immunity.

  20. Spi-B is critical for plasmacytoid dendritic cell function and development.

    Science.gov (United States)

    Sasaki, Izumi; Hoshino, Katsuaki; Sugiyama, Takahiro; Yamazaki, Chihiro; Yano, Takahiro; Iizuka, Akihiko; Hemmi, Hiroaki; Tanaka, Takashi; Saito, Masuyoshi; Sugiyama, Masanaka; Fukuda, Yuri; Ohta, Tomokazu; Sato, Katsuaki; Ainai, Akira; Suzuki, Tadaki; Hasegawa, Hideki; Toyama-Sorimachi, Noriko; Kohara, Hiroshi; Nagasawa, Takashi; Kaisho, Tsuneyasu

    2012-12-01

    Plasmacytoid dendritic cells (pDCs), originating from hematopoietic progenitor cells in the BM, are a unique dendritic cell subset that can produce large amounts of type I IFNs by signaling through the nucleic acid-sensing TLR7 and TLR9 (TLR7/9). The molecular mechanisms for pDC function and development remain largely unknown. In the present study, we focused on an Ets family transcription factor, Spi-B, that is highly expressed in pDCs. Spi-B could transactivate the type I IFN promoters in synergy with IFN regulatory factor 7 (IRF-7), which is an essential transcription factor for TLR7/9-induced type I IFN production in pDCs. Spi-B-deficient pDCs and mice showed defects in TLR7/9-induced type I IFN production. Furthermore, in Spi-B-deficient mice, BM pDCs were decreased and showed attenuated expression of a set of pDC-specific genes whereas peripheral pDCs were increased; this uneven distribution was likely because of defective retainment of mature nondividing pDCs in the BM. The expression pattern of cell-surface molecules in Spi-B-deficient mice indicated the involvement of Spi-B in pDC development. The developmental defects of pDCs in Spi-B-deficient mice were more prominent in the BM than in the peripheral lymphoid organs and were intrinsic to pDCs. We conclude that Spi-B plays critical roles in pDC function and development.

  1. Prominent role for plasmacytoid dendritic cells in mucosal T cell-independent IgA induction.

    Science.gov (United States)

    Tezuka, Hiroyuki; Abe, Yukiko; Asano, Jumpei; Sato, Taku; Liu, Jiajia; Iwata, Makoto; Ohteki, Toshiaki

    2011-02-25

    Although both conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) are present in the gut-associated lymphoid tissues (GALT), the roles of pDCs in the gut remain largely unknown. Here we show a critical role for pDCs in T cell-independent (TI) IgA production by B cells in the GALT. When pDCs of the mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) (which are representative GALT) were cultured with naive B cells to induce TI IgA class switch recombination (CSR), IgA production was substantially higher than in cocultures of these cells with cDCs. IgA production was dependent on APRIL and BAFF production by pDCs. Importantly, pDC expression of APRIL and BAFF was dependent on stromal cell-derived type I IFN signaling under steady-state conditions. Our findings provide insight into the molecular basis of pDC conditioning to induce mucosal TI IgA production, which may lead to improvements in vaccination strategies and treatment for mucosal-related disorders.

  2. IRF8 Transcription Factor Controls Survival and Function of Terminally Differentiated Conventional and Plasmacytoid Dendritic Cells, Respectively

    DEFF Research Database (Denmark)

    Sichien, Dorine; Scott, Charlotte L; Martens, Liesbet

    2016-01-01

    Interferon regulatory factor-8 (IRF8) has been proposed to be essential for development of monocytes, plasmacytoid dendritic cells (pDCs) and type 1 conventional dendritic cells (cDC1s) and remains highly expressed in differentiated DCs. Transcription factors that are required to maintain the ide...

  3. Analysis of HLDA9 mAbs on plasmacytoid dendritic cells.

    Science.gov (United States)

    Cabezón, Raquel; Sintes, Jordi; Llinàs, Laia; Benitez-Ribas, Daniel

    2011-01-30

    Dendritic cells are a heterogeneous population of bone marrow derived leucocytes that play a crucial role in both pathogen recognition and the initiation of primary T cell immune responses. Plasmacytoid dendritic cells (pDCs), also known as natural interferon-producing cells, comprise one of two major human dendritic cell subsets that strongly influences immune balance. pDCs remain a poorly characterized subset. Several studies have suggested the existence of a close phenotypic and functional relationship between B-cells and pDCs. The surface reactivity of a panel of 96 monoclonal antibodies submitted to the ninth Human Leukocyte Differentiation Antigens workshop (HLDA9) B cell section was analyzed using pDCs as target cells. The results showed that eight of the mAbs reacted positively on pDCs: CD86, CD229, CD319, CD305, CD184, CD84, CD85g and FcɛRIa, confirming previously published reports. Interestingly, this study also revealed the expression of eight surface molecules not previously described on pDCs, including CD352(NTBA), CD272(BTLA), CD357(GITR), CD48, CD270(HVEM), Galectin-3, CD148, and CD361. The present report summarizes the expression of these molecules on freshly isolated pDCs. Significantly, we have identified several new molecules expressed by these intriguing cells, ones we believe will open new avenues for the study of pDC functionality and their role in human health and diseases. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Cytokine-producing dendritic cells in the pathogenesis of inflammatory skin diseases

    OpenAIRE

    Johnson-Huang, Leanne M.; McNutt, N. Scott; Krueger, James G.; Lowes, Michelle A.

    2009-01-01

    Inflammatory skin diseases can be examined from many viewpoints. In this review, we consider three distinct cutaneous inflammatory diseases from the point of view of their major lesional dendritic cell (DC) subpopulations. The DC populations considered are Langerhans cells, myeloid DCs, and plasmacytoid DCs (pDCs), with specific attention to the presence and role of the inflammatory counterparts of these cells. From such a “dendritic cell-centric” focus, psoriasis, atopic dermatitis (AD), and...

  5. Plasmacytoid dendritic cells in skin lesions of classic Kaposi's sarcoma.

    Science.gov (United States)

    Karouni, Mirna; Kurban, Mazen; Abbas, Ossama

    2016-09-01

    Plasmacytoid dendritic cells (pDCs) are the most potent producers of type I interferons (IFNs), which allows them to provide anti-viral resistance and to link the innate and adaptive immunity by controlling the function of myeloid DCs, lymphocytes, and natural killer cells. pDCs are involved in the pathogenesis of several infectious [especially viral, such as Molluscum contagiosum (MC)], inflammatory/autoimmune, and neoplastic entities. Kaposi's sarcoma (KS) is a multifocal, systemic lympho-angioproliferative tumor associated with Kaposi's sarcoma-associated herpesvirus (KSHV) infection. Microscopy typically exhibits a chronic inflammatory lymphoplasmacytic infiltrate in addition to the vascular changes and spindle cell proliferation. Despite the extensive research done on the immune evasion strategies employed by KSHV, pDCs role in relation to KS has only rarely been investigated. Given this, we intend to investigate pDC occurrence and activity in the skin lesions of KS. Immunohistochemical staining for BDCA-2 (specific pDC marker) and MxA (surrogate marker for local type I IFN production) was performed on classic KS (n = 20) with the control group comprising inflamed MC (n = 20). As expected, BDCA-2+ pDCs were present in abundance with diffuse and intense MxA expression (indicative of local type I IFN production) in all inflamed MC cases (20 of 20, 100 %). Though present in all the KS cases, pDCs were significantly less abundant in KS than in inflamed MC cases, and MxA expression was patchy/weak in most KS cases. In summary, pDCs are part of the inflammatory host response in KS; however, they were generally low in number with decreased type I IFN production which is probably related to KSHV's ability to evade the immune system through the production of different viral proteins capable of suppressing IFN production as well as pDC function.

  6. Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells.

    Science.gov (United States)

    Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

    2017-01-01

    Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

  7. Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Joanna Bandoła

    2017-08-01

    Full Text Available Plasmacytoid dendritic cells (pDCs regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR by the antigen-presenting pDCs, mediated by toll-like receptor (TLR 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

  8. Dendritic Cell Based Vaccines that Utilize Myeloid Rather than Plasmacytoid Cells Offer a Superior Survival Advantage in Malignant Glioma

    Science.gov (United States)

    Dey, Mahua; Chang, Alan L.; Miska, Jason; Wainwright, Derek A.; Ahmed, Atique U.; Balyasnikova, Irina V.; Pytel, Peter; Han, Yu; Tobias, Alex; Zhang, Lingjiao; Qiao, Jian; Lesniak, Maciej S.

    2015-01-01

    Dendritic cells (DC) are professional antigen presenting cells (APC) that are traditionally divided into two distinct subsets: myeloid DC (mDCs) and plasmacytoid DC (pDCs). pDCs are known for their ability to secrete large amount of IFN-α. Apart from IFN-α production, pDCs can also process antigen and induce T-cell immunity or tolerance. In several solid tumors, pDCs have been shown to play a critical role in promoting tumor immunosuppression. We investigated the role of pDCs in the process of glioma progression in the syngeneic murine model of glioma. We show that glioma-infiltrating pDCs are the major APC in glioma and are deficient in IFN-α secretion (p < 0.05). pDC depletion leads to increased survival of the mice bearing intracranial tumor by decreasing the number of regulatory T-cells (Treg) and by decreasing the suppressive capabilities of Tregs. We subsequently compared the ability of mDCs and pDCs to generate effective anti-glioma immunity in a GL261-OVA mouse model of glioma. Our data suggest that mature pDCs and mDCs isolated from naïve mice can be effectively activated and loaded with SIINFEKL antigen in vitro. Upon intra-dermal injection in the hind leg, a fraction of both types of DCs migrate to the brain and lymph nodes.. Compared to mice vaccinated with pDC or control mice, mice vaccinated with mDCs generated a robust Th1 type immune response, characterized by high frequency of CD4+Tbet+ T-cells and CD8+Siinfekel+ T-cells. This robust anti-tumor T-cell response resulted in tumor eradication and long-term survival in 60% of the animals (p<0.001). PMID:26026061

  9. Effect of natalizumab treatment on circulating plasmacytoid dendritic cells: a cross-sectional observational study in patients with multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Pia Kivisäkk

    Full Text Available Dendritic cells (DCs serve a critical role both in promoting and inhibiting adaptive immunity. The goal of this study was to investigate the effect of natalizumab (NTZ treatment on DC numbers, phenotype, and function in patients with multiple sclerosis (MS.Frequency and phenotype of myeloid and plasmacytoid DCs (MDCs and PDCs, respectively were analyzed in blood from two separate cohorts of untreated, interferon-treated, or NTZ-treated MS patients. In addition, PDCs were stimulated with CpG-containing oligonucleotides or co-cultured with homologous T cells in the presence or absence of NTZ in vitro to determine functional effects of NTZ treatment.We observed that NTZ treatment was associated with a 25-50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged. PDCs in NTZ-treated patients displayed a mature, activated phenotype with increased expression of HLA-DR, TLR9, CCR7, IL-6 and IL-12. In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation.Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype. Taken together the data suggests that transmigration of activated PDCs is preferentially affected by blockade of integrin α4 leading to an increased frequency of activated PDCs in blood.

  10. Dendritic Cell-Based Vaccines that Utilize Myeloid Rather than Plasmacytoid Cells Offer a Superior Survival Advantage in Malignant Glioma.

    Science.gov (United States)

    Dey, Mahua; Chang, Alan L; Miska, Jason; Wainwright, Derek A; Ahmed, Atique U; Balyasnikova, Irina V; Pytel, Peter; Han, Yu; Tobias, Alex; Zhang, Lingjiao; Qiao, Jian; Lesniak, Maciej S

    2015-07-01

    Dendritic cells (DCs) are professional APCs that are traditionally divided into two distinct subsets, myeloid DC (mDCs) and plasmacytoid DC (pDCs). pDCs are known for their ability to secrete large amounts of IFN-α. Apart from IFN-α production, pDCs can also process Ag and induce T cell immunity or tolerance. In several solid tumors, pDCs have been shown to play a critical role in promoting tumor immunosuppression. We investigated the role of pDCs in the process of glioma progression in the syngeneic murine model of glioma. We show that glioma-infiltrating pDCs are the major APC in glioma and are deficient in IFN-α secretion (p < 0.05). pDC depletion leads to increased survival of the mice bearing intracranial tumor by decreasing the number of regulatory T cells (Tregs) and by decreasing the suppressive capabilities of Tregs. We subsequently compared the ability of mDCs and pDCs to generate effective antiglioma immunity in a GL261-OVA mouse model of glioma. Our data suggest that mature pDCs and mDCs isolated from naive mice can be effectively activated and loaded with SIINFEKL Ag in vitro. Upon intradermal injection in the hindleg, a fraction of both types of DCs migrate to the brain and lymph nodes. Compared to mice vaccinated with pDC or control mice, mice vaccinated with mDCs generate a robust Th1 type immune response, characterized by high frequency of CD4(+)T-bet(+) T cells and CD8(+)SIINFEKEL(+) T cells. This robust antitumor T cell response results in tumor eradication and long-term survival in 60% of the animals (p < 0.001).

  11. Plasmacytoid Dendritic Cells and the Control of Herpesvirus Infections

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    Thomas Baranek

    2009-10-01

    Full Text Available Type-I interferons (IFN-I are cytokines essential for vertebrate antiviral defense, including against herpesviruses. IFN-I have potent direct antiviral activities and also mediate a multiplicity of immunoregulatory functions, which can either promote or dampen antiviral adaptive immune responses. Plasmacytoid dendritic cells (pDCs are the professional producers of IFN-I in response to many viruses, including all of the herpesviruses tested. There is strong evidence that pDCs could play a major role in the initial orchestration of both innate and adaptive antiviral immune responses. Depending on their activation pattern, pDC responses may be either protective or detrimental to the host. Here, we summarize and discuss current knowledge regarding pDC implication in the physiopathology of mouse and human herpesvirus infections, and we discuss how pDC functions could be manipulated in immunotherapeutic settings to promote health over disease.

  12. 17beta-estradiol enhances the response of plasmacytoid dendritic cell to CpG.

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    Xiaoxi Li

    Full Text Available Gender differences in immune capabilities suggest that sex hormones such as estrogens were involved in the regulation of the immunocompetence. Numerous studies also suggest that plasmacytoid dendritic cells (PDCs play a pathogenic role in SLE. However, it is unclear whether estrogen can modulate the function of PDCs to influence the development of SLE. In the present study, PDCs from murine spleens were treated with 17beta-estradiol (E2 and CpG respectively or both in vitro, then cell viability, costimulatory molecule expression, cytokine secretion of PDCs, as well as stimulatory capacity of PDCs to B cells were analyzed. Results showed that E2 and CpG increased the cell viability and costimulatory molecule expression on PDCs synergistically. Moreover, the intracellular and extracellular secretion of IFN-alpha was increased by E2 or E2 plus CpG. In addition, E2 and CpG also increased the stimulatory capacity of PDCs to B cells, and the viability of B cells was decreased after neutralizing IFN-alpha significantly. In the experiments in vivo, mice received daily s.c. injections of E2 and CpG respectively or both, then we found that the plasma concentration of IgM were elevated by E2 and CpG synergistically and the expression of IFN-alpha/beta in spleens were noticeably increased by CpG plus E2 compared with the treatment of E2 or CpG only. This study indicates that E2 could exacerbate PDCs' activation with CpG, which further activates B cells to upregulate susceptibility to autoantigens. IFN-alpha plays an important role in the stimulatory effect of PDCs on B cells. E2 stimulation of IFN-alpha production may result in female prevalence in autoimmune diseases such as SLE through activation of PDCs. This study provides novel evidence of relationship between estrogen and SLE and also sheds light on gender biases among SLE patients.

  13. Expression of Plasmacytoid Dendritic Cells, IRF-7, IFN-α mRNA in the Lesions of Psoriasis Vulgaris

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the expression of plasmacytoid dendritic cells (pDCs), interferon regulatory factor-7 (IRF-7) and interferon alpha (IFN- α ) mRNA in skin lesions of patients with psoriasis vulgaris, the expressions of plasmacytoid dendritic cells, IRF-7, IFN-α mRNA in the lesional skin of psoriasis vulgaris were detected by immunohistochemical technique (SP) and RT-PCR. Normal skin of healthy volunteers, serving as control, was also tested. The immunohistochemical study showed that the expression of pDCs in the psoriatic lesions was significantly higher than that in the normal controls. RT-PCR showed that the mRNA expression of IRF-7 was much higher than that in normal controls, but no difference in the expression of IFN-α mRNA was found between two groups. Our findings indicate that up-regulated expression of pDCs, IRF-7mRNA might be involved in the pathogenesis of psoriasis.

  14. Systemic lupus erythematosus immune complexes increase the expression of SLAM family members CD319 (CRACC) and CD229 (LY-9) on plasmacytoid dendritic cells and CD319 on CD56(dim) NK cells.

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    Hagberg, Niklas; Theorell, Jakob; Schlums, Heinrich; Eloranta, Maija-Leena; Bryceson, Yenan T; Rönnblom, Lars

    2013-09-15

    Patients with systemic lupus erythematosus (SLE) display an activated type I IFN system due to unceasing IFN-α release from plasmacytoid dendritic cells (pDCs) stimulated by nucleic acid-containing immune complexes (ICs). NK cells strongly promote the IFN-α production by pDCs; therefore, we investigated surface molecules that could be involved in the pDC-NK cell cross-talk. In human PBMCs stimulated with RNA-containing ICs (RNA-ICs), the expression of the signaling lymphocyte activation molecule (SLAM) family receptors CD319 and CD229 on pDCs and CD319 on CD56(dim) NK cells was selectively increased. Upregulation of CD319 and CD229 on RNA-IC-stimulated pDCs was induced by NK cells or cytokines (e.g., GM-CSF, IL-3). IFN-α-producing pDCs displayed a higher expression of SLAM molecules compared with IFN-α⁻ pDCs. With regard to signaling downstream of SLAM receptors, pDCs expressed SHIP-1, SHP-1, SHP-2, and CSK but lacked SLAM-associated protein (SAP) and Ewing's sarcoma-activated transcript 2 (EAT2), indicating that these receptors may act as inhibitory receptors on pDCs. Furthermore, pDCs from patients with SLE had decreased expression of CD319 on pDCs and CD229 on CD56(dim) NK cells, but RNA-IC stimulation increased CD319 and CD229 expression. In conclusion, this study reveals that the expression of the SLAM receptors CD319 and CD229 is regulated on pDCs and NK cells by lupus ICs and that the expression of these receptors is specifically altered in SLE. These results, together with the observed genetic association between the SLAM locus and SLE, suggest a role for CD319 and CD229 in the SLE disease process.

  15. The Kinetics of Plasmacytoid Dendritic Cell Accumulation in the Pancreas of the NOD Mouse during the Early Phases of Insulitis

    NARCIS (Netherlands)

    J.M.C. Welzen-Coppens (Jojanneke); C.G. van Helden-Meeuwsen; P.J. Leenen (Pieter); H.A. Drexhage (Hemmo); M.A. Versnel (Marjan)

    2013-01-01

    textabstractIn non-obese diabetic (NOD) mice that spontaneously develop autoimmune diabetes, plasmacytoid dendritic cells (pDCs) have a diabetes-promoting role through IFN-α production on one hand, while a diabetes-inhibiting role through indoleamine 2,3-dioxygenase (IDO) production on the other. Li

  16. Plasmacytoid Dendritic Cells in the Tumor Microenvironment: Immune Targets for Glioma Therapeutics

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    Marianela Candolfi

    2012-08-01

    Full Text Available Adenovirus-mediated delivery of the immune-stimulatory cytokine Flt3L and the conditionally cytotoxic thymidine kinase (TK induces tumor regression and long-term survival in preclinical glioma (glioblastoma multiforme [GBM] models. Flt3L induces expansion and recruitment of plasmacytoid dendritic cells (pDCs into the brain. Although pDCs can present antigen and produce powerful inflammatory cytokines, that is, interferon α (IFN-α, their role in tumor immunology remains debated. Thus, we studied the role of pDCs and IFN-α in Ad.TK/GCV+ Ad.Flt3L-mediated anti-GBM therapeutic efficacy. Our data indicate that the combined gene therapy induced recruitment of plasmacytoid DCs (pDCs into the tumor mass; which were capable of in vivo phagocytosis, IFN-α release, and T-cell priming. Thus, we next used either pDCs or an Ad vector encoding IFN-α delivered within the tumor microenvironment. When rats were treated with Ad.TK/GCV in combination with pDCs or Ad-IFN-α, they exhibited 35% and 50% survival, respectively. However, whereas intracranial administration of Ad.TK/GCV + Ad.Flt3L exhibited a high safety profile, Ad-IFN-α led to severe local inflammation, with neurologic and systemic adverse effects. To elucidate whether the efficacy of the immunotherapy was dependent on IFN-α-secreting pDCs, we administered an Ad vector encoding B18R, an IFN-α antagonist, which abrogated the antitumoral effect of Ad.TK/GCV + Ad.Flt3L. Our data suggest that IFN-α release by activated pDCs plays a critical role in the antitumor effect mediated by Ad.TK/GCV + Ad.Flt3L. In summary, taken together, our results demonstrate that pDCs mediate anti-GBM therapeutic efficacy through the production of IFN-α, thus manipulation of pDCs constitutes an attractive new therapeutic target for the treatment of GBM.

  17. Plasmacytoid dendritic cells in the tumor microenvironment: immune targets for glioma therapeutics.

    Science.gov (United States)

    Candolfi, Marianela; King, Gwendalyn D; Yagiz, Kader; Curtin, James F; Mineharu, Yohei; Muhammad, A K M Ghulam; Foulad, David; Kroeger, Kurt M; Barnett, Nick; Josien, Regis; Lowenstein, Pedro R; Castro, Maria G

    2012-08-01

    Adenovirus-mediated delivery of the immune-stimulatory cytokine Flt3L and the conditionally cytotoxic thymidine kinase (TK) induces tumor regression and long-term survival in preclinical glioma (glioblastoma multiforme [GBM]) models. Flt3L induces expansion and recruitment of plasmacytoid dendritic cells (pDCs) into the brain. Although pDCs can present antigen and produce powerful inflammatory cytokines, that is, interferon α (IFN-α), their role in tumor immunology remains debated. Thus, we studied the role of pDCs and IFN-α in Ad.TK/GCV+ Ad.Flt3L-mediated anti-GBM therapeutic efficacy. Our data indicate that the combined gene therapy induced recruitment of plasmacytoid DCs (pDCs) into the tumor mass; which were capable of in vivo phagocytosis, IFN-α release, and T-cell priming. Thus, we next used either pDCs or an Ad vector encoding IFN-α delivered within the tumor microenvironment. When rats were treated with Ad.TK/GCV in combination with pDCs or Ad-IFN-α, they exhibited 35% and 50% survival, respectively. However, whereas intracranial administration of Ad.TK/GCV + Ad.Flt3L exhibited a high safety profile, Ad-IFN-α led to severe local inflammation, with neurologic and systemic adverse effects. To elucidate whether the efficacy of the immunotherapy was dependent on IFN-α-secreting pDCs, we administered an Ad vector encoding B18R, an IFN-α antagonist, which abrogated the antitumoral effect of Ad.TK/GCV + Ad.Flt3L. Our data suggest that IFN-α release by activated pDCs plays a critical role in the antitumor effect mediated by Ad.TK/GCV + Ad.Flt3L. In summary, taken together, our results demonstrate that pDCs mediate anti-GBM therapeutic efficacy through the production of IFN-α, thus manipulation of pDCs constitutes an attractive new therapeutic target for the treatment of GBM.

  18. Environmental alkylphenols modulate cytokine expression in plasmacytoid dendritic cells.

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    Chih-Hsing Hung

    Full Text Available BACKGROUND: Alkylphenols, such as nonylphenol (NP and 4-octylphenol (4-OP, have the potential to disturb immune system due to their weak estrogen-like activity, an effect with potential serious public health impact due to the worldwide distribution of these substances. Plasmacytoid dendritic cells (PDCs can secrete large amounts of type I IFNs and are critical in immune regulation. However, there has been limited study about the influence of alkylphenols on the function of pDCs. OBJECTIVE: The aim of this study was to examine the effect of alkylphenols on pDC functions in vitro and in vivo and then further explored the involved signaling pathways and epigenetic changes. METHODS: Circulating pDCs from human peripheral blood mononuclear cells were treated with alkylphenols with or without CpG stimulation. Alkylphenol-associated cytokine responses, signaling events, histone modifications and viral activity were further examined. In NP-exposed mice, the effect of NP on splenic pDC function and allergic lung inflammation were also assessed. RESULTS: The results showed that NP increased the expression of TNF-α, but suppressed IL-10 production in the range of physiological doses, concomitant with activation of the MKK3/6-p38 signaling pathway and enhanced levels of acetylated histone 3 as well as histone 4 at the TNFA gene locus. Further, in CpG-stimulated pDCs, NP suppressed type I IFNs production, associated with down-regulation of IRF-7 and MKK1/2-ERK-Elk-1 pathways and led to the impaired anti-enterovirus 71 activity in vitro. Additionally, splenic pDCs from NP-exposed mice showed similar cytokine changes upon CpG stimulation under conditions relevant to route and level of exposure in humans. NP treatment also enhanced allergic lung inflammation in vivo. CONCLUSION: Alkylphenols may influence pDCs' functions via their abilities to induce expression of a pro-inflammatory cytokine, TNF-α, and to suppress regulatory cytokines, including IL-10, IFN

  19. Separation of plasmacytoid dendritic cells from B-cell-biased lymphoid progenitor (BLP and Pre-pro B cells using PDCA-1.

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    Kay L Medina

    Full Text Available B-cell-biased lymphoid progenitors (BLPs and Pre-pro B cells lie at a critical juncture between B cell specification and commitment. However, both of these populations are heterogenous, which hampers investigation into the molecular changes that occur as lymphoid progenitors commit to the B cell lineage. Here, we demonstrate that there are PDCA-1(+Siglec H(+ plasmacytoid dendritic cells (pDCs that co-purify with BLPs and Pre-pro B cells, which express little or no CD11c or Ly6C. Removal of PDCA-1(+ pDCs separates B cell progenitors that express high levels of a Rag1-GFP reporter from Rag1-GFP(low/neg pDCs within the BLP and Pre-pro B populations. Analysis of Flt3-ligand knockout and IL-7Rα knockout mice revealed that there is a block in B cell development at the all-lymphoid progenitor (ALP stage, as the majority of cells within the BLP or Pre-pro B gates were PDCA-1(+ pDCs. Thus, removal of PDCA-1(+ pDCs is critical for analysis of BLP and Pre-pro B cell populations. Analysis of B cell potential within the B220(+CD19(- fraction demonstrated that AA4.1(+Ly6D(+PDCA-1(- Pre-pro B cells gave rise to CD19(+ B cells at high frequency, while PDCA-1(+ pDCs in this fraction did not. Interestingly, the presence of PDCA-1(+ pDCs within CLPs may help to explain the conflicting results regarding the origin of these cells.

  20. Phospholipid Scramblase 1 regulates Toll-like receptor 9-mediated type I interferon production in plasmacytoid dendritic cells

    Science.gov (United States)

    Talukder, Amjad H; Bao, Musheng; Kim, Tae Whan; Facchinetti, Valeria; Hanabuchi, Shino; Bover, Laura; Zal, Tomasz; Liu, Yong-Jun

    2012-01-01

    Toll-like receptor 9 (TLR9) senses microbial DNA in the endosomes of plasmacytoid dendritic cells (pDCs) and triggers MyD88-dependent type I interferon (IFN) responses. To better understand TLR9 biology in pDCs, we established a yeast two-hybrid library for the identification of TLR9-interacting proteins. Here, we report that an IFN-inducible protein, phospholipid scramblase 1 (PLSCR1), interacts with TLR9 in pDCs. Knockdown of PLSCR1 expression by siRNA in human pDC cell line led to a 60-70% reduction of IFN-α responses following CpG-ODN (oligodeoxynucleotide) stimulation. Primary pDCs from PLSCR1-deficient mice produced lower amount of type 1 IFN than pDCs from the wild-type mice in response to CpG-ODN, herpes simplex virus and influenza A virus. Following CpG-A stimulation, there were much lower amounts of TLR9 in the early endosomes together with CpG-A in pDCs from PLSCR1-deficient mice. Our study demonstrates that PLSCR1 is a TLR9-interacting protein that plays an important role in pDC's type 1 IFN responses by regulating TLR9 trafficking to the endosomal compartment. PMID:22453241

  1. A correlation of measles specific antibodies and the number of plasmacytoid dendritic cells is observed after measles vaccination in 9 month old infants.

    Science.gov (United States)

    García-León, Miguel L; Bonifaz, Laura C; Espinosa-Torres, Bogart; Hernández-Pérez, Brenda; Cardiel-Marmolejo, Lino; Santos-Preciado, José I; Wong-Chew, Rosa M

    2015-01-01

    Measles virus (MeV) represents one of the main causes of death among young children, particularly in developing countries. Upon infection, MeV controls both interferon induction (IFN) and the interferon signaling pathway which results in a severe host immunosuppression that can persists for up to 6 mo after infection. Despite the global biology of MeV infection is well studied, the role of the plasmacytoid dendritic cells (pDCs) during the host innate immune response after measles vaccination remains largely uncharacterized. Here we investigated the role of pDCs, the major producers of interferon in response to viral infections, in the development of adaptive immune response against MeV vaccine. We report that there is a strong correlation between pDCs population and the humoral immune response to Edmonston Zagreb (EZ) measles vaccination in 9-month-old mexican infants. Five infants were further evaluated after vaccination, showing a clear increase in pDCs at baseline, one week and 3 months after immunization. Three months postvaccination they showed increase in memory T-cells and pDCs populations, high induction of adaptive immunity and also observed a correlation between pDCs number and the humoral immune response. These findings suggest that the development and magnitude of the adaptive immune response following measles immunization is directly dependent on the number of pDCs of the innate immune response.

  2. A correlation of measles specific antibodies and the number of plasmacytoid dendritic cells is observed after measles vaccination in 9 month old infants

    Science.gov (United States)

    García-León, Miguel L; Bonifaz, Laura C; Espinosa-Torres, Bogart; Hernández-Pérez, Brenda; Cardiel-Marmolejo, Lino; Santos-Preciado, José I; Wong-Chew, Rosa M

    2015-01-01

    Measles virus (MeV) represents one of the main causes of death among young children, particularly in developing countries. Upon infection, MeV controls both interferon induction (IFN) and the interferon signaling pathway which results in a severe host immunosuppression that can persists for up to 6 mo after infection. Despite the global biology of MeV infection is well studied, the role of the plasmacytoid dendritic cells (pDCs) during the host innate immune response after measles vaccination remains largely uncharacterized. Here we investigated the role of pDCs, the major producers of interferon in response to viral infections, in the development of adaptive immune response against MeV vaccine. We report that there is a strong correlation between pDCs population and the humoral immune response to Edmonston Zagreb (EZ) measles vaccination in 9-month-old mexican infants. Five infants were further evaluated after vaccination, showing a clear increase in pDCs at baseline, one week and 3 months after immunization. Three months postvaccination they showed increase in memory T-cells and pDCs populations, high induction of adaptive immunity and also observed a correlation between pDCs number and the humoral immune response. These findings suggest that the development and magnitude of the adaptive immune response following measles immunization is directly dependent on the number of pDCs of the innate immune response. PMID:26075901

  3. Constitutive plasmacytoid dendritic cell migration to the splenic white pulp is cooperatively regulated by CCR7- and CXCR4-mediated signaling.

    Science.gov (United States)

    Umemoto, Eiji; Otani, Kazuhiro; Ikeno, Takashi; Verjan Garcia, Noel; Hayasaka, Haruko; Bai, Zhongbin; Jang, Myoung Ho; Tanaka, Toshiyuki; Nagasawa, Takashi; Ueda, Koichi; Miyasaka, Masayuki

    2012-07-01

    Although the spleen plays an important role in host defense against infection, the mechanism underlying the migration of the innate immune cells, plasmacytoid dendritic cells (pDCs), into the spleen remains ill defined. In this article, we report that pDCs constitutively migrate into the splenic white pulp (WP) in a manner dependent on the chemokine receptors CCR7 and CXCR4. In CCR7-deficient mice and CCR7 ligand-deficient mice, compared with wild-type (WT) mice, substantially fewer pDCs were found in the periarteriolar lymphoid sheath of the splenic WP under steady-state conditions. In addition, the migration of adoptively transferred CCR7-deficient pDCs into the WP was significantly worse than that of WT pDCs, supporting the idea that pDC trafficking to the splenic WP requires CCR7 signaling. WT pDCs responded to a CCR7 ligand with modest chemotaxis and ICAM-1 binding in vitro, and priming with the CCR7 ligand enabled the pDCs to migrate efficiently toward low concentrations of CXCL12 in a CXCR4-dependent manner, raising the possibility that CCR7 signaling enhances CXCR4-mediated pDC migration. In agreement with this hypothesis, CCL21 and CXCL12 were colocalized on fibroblastic reticular cells in the T cell zone and in the marginal zone bridging channels, through which pDCs appeared to enter the WP. Furthermore, functional blockage of CCR7 and CXCR4 abrogated pDC trafficking into the WP. Collectively, these results strongly suggest that pDCs employ both CCR7 and CXCR4 as critical chemokine receptors to migrate into the WP under steady-state conditions.

  4. Recognition of Aspergillus fumigatus hyphae by human plasmacytoid dendritic cells is mediated by dectin-2 and results in formation of extracellular traps.

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    Flávio V Loures

    2015-02-01

    Full Text Available Plasmacytoid dendritic cells (pDCs were initially considered as critical for innate immunity to viruses. However, our group has shown that pDCs bind to and inhibit the growth of Aspergillus fumigatus hyphae and that depletion of pDCs renders mice hypersusceptible to experimental aspergillosis. In this study, we examined pDC receptors contributing to hyphal recognition and downstream events in pDCs stimulated by A. fumigatus hyphae. Our data show that Dectin-2, but not Dectin-1, participates in A. fumigatus hyphal recognition, TNF-α and IFN-α release, and antifungal activity. Moreover, Dectin-2 acts in cooperation with the FcRγ chain to trigger signaling responses. In addition, using confocal and electron microscopy we demonstrated that the interaction between pDCs and A. fumigatus induced the formation of pDC extracellular traps (pETs containing DNA and citrullinated histone H3. These structures closely resembled those of neutrophil extracellular traps (NETs. The microarray analysis of the pDC transcriptome upon A. fumigatus infection also demonstrated up-regulated expression of genes associated with apoptosis as well as type I interferon-induced genes. Thus, human pDCs directly recognize A. fumigatus hyphae via Dectin-2; this interaction results in cytokine release and antifungal activity. Moreover, hyphal stimulation of pDCs triggers a distinct pattern of pDC gene expression and leads to pET formation.

  5. E2-2 Dependent Plasmacytoid Dendritic Cells Control Autoimmune Diabetes.

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    Lisbeth Hansen

    Full Text Available Autoimmune diabetes is a consequence of immune-cell infiltration and destruction of pancreatic β-cells in the islets of Langerhans. We analyzed the cellular composition of the insulitic lesions in the autoimmune-prone non-obese diabetic (NOD mouse and observed a peak in recruitment of plasmacytoid dendritic cells (pDCs to NOD islets around 8-9 weeks of age. This peak coincides with increased spontaneous expression of type-1-IFN response genes and CpG1585 induced production of IFN-α from NOD islets. The transcription factor E2-2 is specifically required for the maturation of pDCs, and we show that knocking out E2-2 conditionally in CD11c+ cells leads to a reduced recruitment of pDCs to pancreatic islets and reduced CpG1585 induced production of IFN-α during insulitis. As a consequence, insulitis has a less aggressive expression profile of the Th1 cytokine IFN-γ and a markedly reduced diabetes incidence. Collectively, these observations demonstrate a disease-promoting role of E2-2 dependent pDCs in the pancreas during autoimmune diabetes in the NOD mouse.

  6. E2-2 Dependent Plasmacytoid Dendritic Cells Control Autoimmune Diabetes

    Science.gov (United States)

    Hansen, Lisbeth; Schmidt-Christensen, Anja; Gupta, Shashank; Fransén-Pettersson, Nina; Hannibal, Tine D.; Reizis, Boris; Santamaria, Pere; Holmberg, Dan

    2015-01-01

    Autoimmune diabetes is a consequence of immune-cell infiltration and destruction of pancreatic β-cells in the islets of Langerhans. We analyzed the cellular composition of the insulitic lesions in the autoimmune-prone non-obese diabetic (NOD) mouse and observed a peak in recruitment of plasmacytoid dendritic cells (pDCs) to NOD islets around 8–9 weeks of age. This peak coincides with increased spontaneous expression of type-1-IFN response genes and CpG1585 induced production of IFN-α from NOD islets. The transcription factor E2-2 is specifically required for the maturation of pDCs, and we show that knocking out E2-2 conditionally in CD11c+ cells leads to a reduced recruitment of pDCs to pancreatic islets and reduced CpG1585 induced production of IFN-α during insulitis. As a consequence, insulitis has a less aggressive expression profile of the Th1 cytokine IFN-γ and a markedly reduced diabetes incidence. Collectively, these observations demonstrate a disease-promoting role of E2-2 dependent pDCs in the pancreas during autoimmune diabetes in the NOD mouse. PMID:26624013

  7. Circulating dendritic cell number and intracellular TNF-α production in women with type 2 diabetes.

    Science.gov (United States)

    Blank, Sally E; Johnson, Emily Carolyn; Weeks, Debra K; Wysham, Carol H

    2012-12-01

    Human dendritic cell (DC) subsets perform specialized functions for surveillance against bacterial and viral infections essential for the management of type 2 diabetes (T2D). Production of tumor necrosis factor-alpha (TNF-α) by DCs acts in autocrine fashion to regulate DC maturation and promotes the inflammatory response. This study was designed to compare circulating DC number and intracellular TNF-α production between post-menopausal women with T2D and healthy women. Blood samples were obtained (n = 21/group) and examined for plasma glucose and TNF-α concentrations, and dendritic cell subset immunophenotype (plasmacytoid, pDC, CD85k(ILT-3)(+)CD123(+)CD16(-)CD14(-) and myeloid, mDC, CD85k(ILT-3)(+)CD33(+)CD123(dim to neg)CD16(-)CD14(dim to neg)). Intracellular production of TNF-α was determined in unstimulated and stimulated DCs. Women with T2D had significantly (P TNF-α concentrations when compared to healthy women. Women with T2D having poor glycemic control (T2D Poor Control, HbA1c ≥ 7%) had fewer circulating pDCs than women with T2D having good glycemic control (T2D Good Control, HbA1c TNF-α in stimulated pDCs. Intracellular production of TNF-α in pDCs was significantly greater in healthy vs. T2D Poor Control (P production of TNF-α did not differ between groups. These findings indicate that TNF-α production by pDCs was reduced in women with T2D and circulating number of pDCs was associated with glycemic control.

  8. Plasmacytoid dendritic cells prevent cigarette smoke and Chlamydophila pneumoniae-induced Th2 inflammatory responses.

    Science.gov (United States)

    Sorrentino, Rosalinda; Gray, Pearl; Chen, Shuang; Shimada, Kenichi; Crother, Timothy R; Arditi, Moshe

    2010-10-01

    Smoking promotes the development of allergic asthma and pneumonia. Chlamydophila pneumoniae lung infection is associated with an increased risk for asthma, inducing an immune response regulated by dendritic cells (DCs). This study sought to determine whether exposure to cigarette smoke modulates the functional activity of CD11c-positive DCs in the lung, with and without concomitant C. pneumoniae infection. Bone marrow-derived DCs (BMDCs) were exposed in vitro to cigarette smoke extract (CSE) and/or live C. pneumoniae (Cpn), and then adoptively transferred intratracheally into wild-type mice. Although CSE plus Cpn appeared to exert an additive effect on the production of Th2 cytokines in vitro, we did not see this effect in vivo. However, the adoptive transfer of DCs pulsed with both CSE and C. pneumoniae into the lungs of naive mice led to an influx of plasmacytoid DCs (pDCs) that suppressed the Th2 skewing ability of the transferred BMDCs. The depletion of pDCs by antibody restored the Th2 skewing ability of the BMDCs. The expression of indoleamine-2,3-dioxygenase in the lung was reduced after the depletion of pDCs, and blocking IFN-α in vitro prevented the ability of pDCs to inhibit the Th2 responses induced by myeloid DCs (mDCs), suggesting their potential involvement in the mechanism of altered polarization. In conclusion, exposure to cigarette smoke skews C. pneumoniae-induced mDCs responses toward a Th2 bias in the lung, which is prevented by pDCs. We propose that pDCs may play a major role in the immunosuppressive lung environment in smokers with C. pneumoniae infection.

  9. Differential Activation of Human Monocyte-Derived and Plasmacytoid Dendritic Cells by West Nile Virus Generated in Different Host Cells▿

    Science.gov (United States)

    Silva, Maria Carlan; Guerrero-Plata, Antonieta; Gilfoy, Felicia D.; Garofalo, Roberto P.; Mason, Peter W.

    2007-01-01

    Dendritic cells (DCs) play a central role in innate immunity and antiviral responses. In this study, we investigated the production of alpha interferon (IFN-α) and inducible chemokines by human monocyte-derived dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) infected with West Nile virus (WNV), an emergent pathogen whose infection can lead to severe cases of encephalitis in the elderly, children, and immunocompromised individuals. Our experiments demonstrated that WNV grown in mammalian cells (WNVVero) was a potent inducer of IFN-α secretion in pDCs and, to a lesser degree, in mDCs. The ability of WNVVero to induce IFN-α in pDCs did not require viral replication and was prevented by the treatment of cells with bafilomycin A1 and chloroquine, suggesting that it was dependent on endosomal Toll-like receptor recognition. On the other hand, IFN-α production in mDCs required viral replication and was associated with the nuclear translocation of IRF3 and viral antigen expression. Strikingly, pDCs failed to produce IFN-α when stimulated with WNV grown in mosquito cells (WNVC7/10), while mDCs responded similarly to WNVVero or WNVC7/10. Moreover, the IFN-dependent chemokine IP-10 was produced in substantial amounts by pDCs in response to WNVVero but not WNVC7/10, while interleukin-8 was produced in greater amounts by mDCs infected with WNVC7/10 than in those infected with WNVVero. These findings suggest that cell-specific mechanisms of WNV recognition leading to the production of type I IFN and inflammatory chemokines by DCs may contribute to both the innate immune response and disease pathogenesis in human infections. PMID:17913823

  10. Delta-like1-induced Notch1 signaling regulates the human plasmacytoid dendritic cell versus T-cell lineage decision through control of GATA-3 and Spi-B

    NARCIS (Netherlands)

    W. Dontje; R. Schotte; T. Cupedo; M. Nagasawa; F. Scheeren; R. Gimeno; H. Spits; B. Blom

    2006-01-01

    Human early thymic precursors have the potential to differentiate into multiple cell lineages, including T cells and plasmacytoid dendritic cells (pDCs). This decision is guided by the induction or silencing of lineage-specific transcription factors. The ETS family member Spi-B is a key regulator of

  11. Dendritic cell subtypes from lymph nodes and blood show contrasted gene expression programs upon Bluetongue virus infection.

    Science.gov (United States)

    Ruscanu, Suzana; Jouneau, Luc; Urien, Céline; Bourge, Mickael; Lecardonnel, Jérôme; Moroldo, Marco; Loup, Benoit; Dalod, Marc; Elhmouzi-Younes, Jamila; Bevilacqua, Claudia; Hope, Jayne; Vitour, Damien; Zientara, Stéphan; Meyer, Gilles; Schwartz-Cornil, Isabelle

    2013-08-01

    Human and animal hemorrhagic viruses initially target dendritic cells (DCs). It has been proposed, but not documented, that both plasmacytoid DCs (pDCs) and conventional DCs (cDCs) may participate in the cytokine storm encountered in these infections. In order to evaluate the contribution of DCs in hemorrhagic virus pathogenesis, we performed a genome-wide expression analysis during infection by Bluetongue virus (BTV), a double-stranded RNA virus that induces hemorrhagic fever in sheep and initially infects cDCs. Both pDCs and cDCs accumulated in regional lymph nodes and spleen during BTV infection. The gene response profiles were performed at the onset of the disease and markedly differed with the DC subtypes and their lymphoid organ location. An integrative knowledge-based analysis revealed that blood pDCs displayed a gene signature related to activation of systemic inflammation and permeability of vasculature. In contrast, the gene profile of pDCs and cDCs in lymph nodes was oriented to inhibition of inflammation, whereas spleen cDCs did not show a clear functional orientation. These analyses indicate that tissue location and DC subtype affect the functional gene expression program induced by BTV and suggest the involvement of blood pDCs in the inflammation and plasma leakage/hemorrhage during BTV infection in the real natural host of the virus. These findings open the avenue to target DCs for therapeutic interventions in viral hemorrhagic diseases.

  12. Role of PU.1 in MHC Class II Expression via CIITA Transcription in Plasmacytoid Dendritic Cells.

    Science.gov (United States)

    Miura, Ryosuke; Kasakura, Kazumi; Nakano, Nobuhiro; Hara, Mutsuko; Maeda, Keiko; Okumura, Ko; Ogawa, Hideoki; Yashiro, Takuya; Nishiyama, Chiharu

    2016-01-01

    The cofactor CIITA is a master regulator of MHC class II expression and several transcription factors regulating the cell type-specific expression of CIITA have been identified. Although the MHC class II expression in plasmacytoid dendritic cells (pDCs) is also mediated by CIITA, the transcription factors involved in the CIITA expression in pDCs are largely unknown. In the present study, we analyzed the role of a hematopoietic lineage-specific transcription factor, PU.1, in CIITA transcription in pDCs. The introduction of PU.1 siRNA into mouse pDCs and a human pDC cell line, CAL-1, reduced the mRNA levels of MHC class II and CIITA. When the binding of PU.1 to the 3rd promoter of CIITA (pIII) in CAL-1 and mouse pDCs was analyzed by a chromatin immunoprecipitation assay, a significant amount of PU.1 binding to the pIII was detected, which was definitely decreased in PU.1 siRNA-transfected cells. Reporter assays showed that PU.1 knockdown reduced the pIII promoter activity and that three Ets-motifs in the human pIII promoter were candidates of cis-enhancing elements. By electrophoretic mobility shift assays, it was confirmed that two Ets-motifs, GGAA (-181/-178) and AGAA (-114/-111), among three candidates, were directly bound with PU.1. When mouse pDCs and CAL-1 cells were stimulated by GM-CSF, mRNA levels of PU.1, pIII-driven CIITA, total CIITA, MHC class II, and the amount of PU.1 binding to pIII were significantly increased. The GM-CSF-mediated up-regulation of these mRNAs was canceled in PU.1 siRNA-introduced cells. Taking these results together, we conclude that PU.1 transactivates the pIII through direct binding to Ets-motifs in the promoter in pDCs.

  13. Human pDCs display sex-specific differences in type I interferon subtypes and interferon α/β receptor expression.

    Science.gov (United States)

    Ziegler, Susanne M; Beisel, Claudia; Sutter, Kathrin; Griesbeck, Morgane; Hildebrandt, Heike; Hagen, Sven H; Dittmer, Ulf; Altfeld, Marcus

    2017-02-01

    The outcomes of many diseases differ between women and men, with women experiencing a higher incidence and more severe pathogenesis of autoimmune and some infectious diseases. It has been suggested that this is partially due to activation of plasmacytoid dendritic cells (pDCs), the main producers of interferon (IFN)-α, in response to toll-like receptor (TLR)7 stimulation. We investigated the induction of type I IFN (IFN-I) subtypes upon TLR7 stimulation on isolated pDCs. Our data revealed a sex-specific differential expression of IFN-Is, with pDCs from females showing a significantly higher mRNA expression of all 13 IFN-α subtypes. In addition, pDCs from females had higher levels of IFN-β mRNA after stimulation, indicating that sex differences in IFN-I production by pDCs were mediated by a signaling event upstream of the first loop of IFN-I mRNA transcription. Furthermore, the surface expression levels of the common IFN-α/β receptor subunit 2 were significantly higher on pDCs from females in comparison to males. These data indicate that higher IFN-α production is already established at the mRNA level and propose a contribution of higher IFN-α/β receptor 2 expression on pDCs to the immunological differences in IFN-I production observed between females and males. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Selective Expression of the MAPK Phosphatase Dusp9/MKP-4 in Mouse Plasmacytoid Dendritic Cells and Regulation of IFN-beta Production

    DEFF Research Database (Denmark)

    Niedzielska, Magdalena; Raffi, Faizal A. M.; Tel, Jurjen;

    2015-01-01

    Plasmacytoid dendritic cells (pDCs) efficiently produce large amounts of type I IFN in response to TLR7 and TLR9 ligands, whereas conventional DCs (cDCs) predominantly secrete high levels of the cytokines IL-10 and IL-12. The molecular basis underlying this distinct phenotype is not well understood...... is sufficient to impair ERK1/2 activation and enhance IFN-beta expression. However, despite selective expression in pDCs, Dusp9 is not essential for high-level IFN-beta production by these cells....

  15. Tolerogenic pDCs: spotlight on Foxo3.

    Science.gov (United States)

    Bronte, Vincenzo

    2011-04-01

    Cancer creates a peculiar inflammatory environment enriched for transcription factors with a negative influence on adaptive immunity. In this issue of the JCI, Watkins and colleagues identify Foxo3 as a master regulator of the tolerogenic program in tumor-associated, plasmacytoid DCs (pDCs). Foxo3 enables pDCs to induce tolerance in tumor antigen-specific CD8+ T cells, turning them into regulatory lymphocytes capable of inhibiting nearby CD8+ T lymphocytes. Provision of tumor-specific CD4+ T helper cells interrupts this circuit by inhibiting Foxo3 expression and fully licensing the antigen-presenting ability of pDCs. These data identify a new target for therapeutic intervention and provide insight into the transcription factor interplay in myeloid cells recruited to the cancer microenvironment.

  16. Plasmacytoid dendritic cells play a role for effective innate immune responses during Chlamydia pneumoniae infection in mice.

    Directory of Open Access Journals (Sweden)

    Timothy R Crother

    Full Text Available Plasmacytoid dendritic cells (pDCs are known for their robust antiviral response and their pro-tolerance effects towards allergic diseases and tissue engraftments. However, little is known about the role pDCs may play during a bacterial infection, including pulmonary Chlamydia pneumoniae (CP. In this study, we investigated the role of pDCs during pulmonary CP infection. Our results revealed that depletion of pDCs during acute CP infection in mice results in delayed and reduced lung inflammation, with an early delay in cellular recruitment and significant reduction in early cytokine production in the lungs. This was followed by impaired and delayed bacterial clearance from the lungs which then resulted in a severe and prolonged chronic inflammation and iBALT like structures containing large numbers of B and T cells in these animals. We also observed that increasing the pDC numbers in the lung by FLT3L treatment experimentally results in greater lung inflammation during acute CP infection. In contrast to these results, restimulation of T-cells in the draining lymph nodes of pDC-depleted mice induced greater amounts of proinflammatory cytokines than we observed in control mice. These results suggest that pDCs in the lung may provide critical proinflammatory innate immune responses in response to CP infection, but are suppressive towards adaptive immune responses in the lymph node. Thus pDCs in the lung and the draining lymph node appear to have different roles and phenotypes during acute CP infection and may play a role in host immune responses.

  17. Plasmacytoid dendritic cells play a role for effective innate immune responses during Chlamydia pneumoniae infection in mice.

    Science.gov (United States)

    Crother, Timothy R; Ma, Jun; Jupelli, Madhulika; Chiba, Norika; Chen, Shuang; Slepenkin, Anatoly; Alsabeh, Randa; Peterson, Ellena; Shimada, Kenichi; Arditi, Moshe

    2012-01-01

    Plasmacytoid dendritic cells (pDCs) are known for their robust antiviral response and their pro-tolerance effects towards allergic diseases and tissue engraftments. However, little is known about the role pDCs may play during a bacterial infection, including pulmonary Chlamydia pneumoniae (CP). In this study, we investigated the role of pDCs during pulmonary CP infection. Our results revealed that depletion of pDCs during acute CP infection in mice results in delayed and reduced lung inflammation, with an early delay in cellular recruitment and significant reduction in early cytokine production in the lungs. This was followed by impaired and delayed bacterial clearance from the lungs which then resulted in a severe and prolonged chronic inflammation and iBALT like structures containing large numbers of B and T cells in these animals. We also observed that increasing the pDC numbers in the lung by FLT3L treatment experimentally results in greater lung inflammation during acute CP infection. In contrast to these results, restimulation of T-cells in the draining lymph nodes of pDC-depleted mice induced greater amounts of proinflammatory cytokines than we observed in control mice. These results suggest that pDCs in the lung may provide critical proinflammatory innate immune responses in response to CP infection, but are suppressive towards adaptive immune responses in the lymph node. Thus pDCs in the lung and the draining lymph node appear to have different roles and phenotypes during acute CP infection and may play a role in host immune responses.

  18. Plasmacytoid dendritic cell-derived IFNα modulates Th17 differentiation during early Bordetella pertussis infection in mice.

    Science.gov (United States)

    Wu, V; Smith, A A; You, H; Nguyen, T A; Ferguson, R; Taylor, M; Park, J E; Llontop, P; Youngman, K R; Abramson, T

    2016-05-01

    Whooping cough is a highly contagious respiratory disease caused by Bordetella pertussis (B. pertussis). T helper 17 (Th17) cells have a central role in the resolution of the infection. Emerging studies document that type I interferons (IFNs) suppress Th17 differentiation and interleukin (IL)-17 responses in models of infection and chronic inflammation. As plasmacytoid dendritic cells (pDCs) are a major source of type I IFNs, we hypothesize that during B. pertussis infection in mice, pDC-derived IFNα inhibits a rapid increase in Th17 cells. We found that IFNα-secreting pDCs appear in the lungs during the early stages of infection, while a robust rise of Th17 cells in the lungs is detected at 15 days post-infection or later. The presence of IFNα led to reduced Th17 differentiation and proliferation in vitro. Furthermore, in vivo blocking of IFNα produced by pDCs during infection with B. pertussis infection resulted in early increase of Th17 frequency, inflammation, and reduced bacterial loads in the airways of infected mice. Taken together, the experiments reported here describe an inhibitory role for pDCs and pDC-derived IFNα in modulating Th17 responses during the early stages of B. pertussis infection, which may explain the prolonged nature of whooping cough.

  19. Plasmacytoid Dendritic Cell Response to CpG ODN Correlates with CXCL16 Expression and Is Inhibited by ox-LDL

    Directory of Open Access Journals (Sweden)

    Mayda Gursel

    2013-01-01

    Full Text Available Structurally distinct classes of synthetic CpG oligonucleotides (ODN differentially activate human immune cells. K-type ODN trigger plasmacytoid dendritic cells (pDCs to differentiate and produce TNFα. In contrast, D-type ODN stimulate large amounts of IFNα secretion from pDCs. The cell-surface receptor CXCL16 was previously shown to influence the nature and specificity of CpG ODN-induced immune activation. Here, we evaluated the expression and function of CXCL16 on pDC from healthy volunteers. We report that increased CXCL16 expression correlated with enhanced in vitro response exclusively to D-type CpG ODN. Conversely, enzymatic digestion of the receptor resulted in a decrease in IFNα production. Moreover, ox-LDL presence significantly inhibited D-ODN mediated IFNα production by pDCs. Coculture of enriched pDCs with the CXCR6 expressing Jurkat T cells decreased the activation threshold of these cells responding to D-ODN, suggesting that CXCL16/CXCR6 interaction may play an important role in modifying the response of pDCs to environmental danger signals.

  20. The Deterministic Dendritic Cell Algorithm

    CERN Document Server

    Greensmith, Julie

    2010-01-01

    The Dendritic Cell Algorithm is an immune-inspired algorithm orig- inally based on the function of natural dendritic cells. The original instantiation of the algorithm is a highly stochastic algorithm. While the performance of the algorithm is good when applied to large real-time datasets, it is difficult to anal- yse due to the number of random-based elements. In this paper a deterministic version of the algorithm is proposed, implemented and tested using a port scan dataset to provide a controllable system. This version consists of a controllable amount of parameters, which are experimented with in this paper. In addition the effects are examined of the use of time windows and variation on the number of cells, both which are shown to influence the algorithm. Finally a novel metric for the assessment of the algorithms output is introduced and proves to be a more sensitive metric than the metric used with the original Dendritic Cell Algorithm.

  1. Rotavirus structural proteins and dsRNA are required for the human primary plasmacytoid dendritic cell IFNalpha response.

    Directory of Open Access Journals (Sweden)

    Emily M Deal

    Full Text Available Rotaviruses are the leading cause of severe dehydrating diarrhea in children worldwide. Rotavirus-induced immune responses, especially the T and B cell responses, have been extensively characterized; however, little is known about innate immune mechanisms involved in the control of rotavirus infection. Although increased levels of systemic type I interferon (IFNalpha and beta correlate with accelerated resolution of rotavirus disease, multiple rotavirus strains, including rhesus rotavirus (RRV, have been demonstrated to antagonize type I IFN production in a variety of epithelial and fibroblast cell types through several mechanisms, including degradation of multiple interferon regulatory factors by a viral nonstructural protein. This report demonstrates that stimulation of highly purified primary human peripheral plasmacytoid dendritic cells (pDCs with either live or inactivated RRV induces substantial IFNalpha production by a subset of pDCs in which RRV does not replicate. Characterization of pDC responses to viral stimulus by flow cytometry and Luminex revealed that RRV replicates in a small subset of human primary pDCs and, in this RRV-permissive small subset, IFNalpha production is diminished. pDC activation and maturation were observed independently of viral replication and were enhanced in cells in which virus replicates. Production of IFNalpha by pDCs following RRV exposure required viral dsRNA and surface proteins, but neither viral replication nor activation by trypsin cleavage of VP4. These results demonstrate that a minor subset of purified primary human peripheral pDCs are permissive to RRV infection, and that pDCs retain functionality following RRV stimulus. Additionally, this study demonstrates trypsin-independent infection of primary peripheral cells by rotavirus, which may allow for the establishment of extraintestinal viremia and antigenemia. Importantly, these data provide the first evidence of IFNalpha induction in primary

  2. Donor lung derived myeloid and plasmacytoid dendritic cells differentially regulate T cell proliferation and cytokine production

    Directory of Open Access Journals (Sweden)

    Benson Heather L

    2012-03-01

    Full Text Available Abstract Background Direct allorecognition, i.e., donor lung-derived dendritic cells (DCs stimulating recipient-derived T lymphocytes, is believed to be the key mechanism of lung allograft rejection. Myeloid (cDCs and plasmacytoid (pDCs are believed to have differential effects on T cell activation. However, the roles of each DC type on T cell activation and rejection pathology post lung transplantation are unknown. Methods Using transgenic mice and antibody depletion techniques, either or both cell types were depleted in lungs of donor BALB/c mice (H-2d prior to transplanting into C57BL/6 mice (H-2b, followed by an assessment of rejection pathology, and pDC or cDC-induced proliferation and cytokine production in C57BL/6-derived mediastinal lymph node T cells (CD3+. Results Depleting either DC type had modest effect on rejection pathology and T cell proliferation. In contrast, T cells from mice that received grafts depleted of both DCs did not proliferate and this was associated with significantly reduced acute rejection scores compared to all other groups. cDCs were potent inducers of IFNγ, whereas both cDCs and pDCs induced IL-10. Both cell types had variable effects on IL-17A production. Conclusion Collectively, the data show that direct allorecognition by donor lung pDCs and cDCs have differential effects on T cell proliferation and cytokine production. Depletion of both donor lung cDC and pDC could prevent the severity of acute rejection episodes.

  3. Decrease in circulating plasmacytoid dendritic cells during short-term systemic normobaric hypoxia.

    Science.gov (United States)

    Yilmaz, Atilla; Ratka, Josi; Rohm, Ilonka; Pistulli, Rudin; Goebel, Bjorn; Asadi, Yahya; Petri, Alexander; Kiehntopf, Michael; Figulla, Hans R; Jung, Christian

    2016-02-01

    During exposure to high altitude, the immune system is altered. During hypoxia, an increase in interleukin (IL)-6 and high sensitivity C-reactive protein (hs-CRP), and an increase in natural killer cells and decrease in T cells in blood was shown. However, the impact of hypoxia on dendritic cells has not been investigated yet. Twelve healthy volunteers were subjected to a transient normobaric hypoxia for 6·5 h simulating an oxygen concentration at 5500 m. During exposure to hypoxia, blood samples were collected and analysed by flow cytometrical cell sorting (FACS) for circulating myeloid (mDCs) and plasmacytoid (pDCs) DCs. Serum levels of IL-6 and tumour necrosis factor (TNF)-α were analysed. In a cell culture hypoxia chamber, blood samples were subjected to the same hypoxia and analysed regarding DCs. Exposure to normobaric hypoxia induced a significant decrease in circulating pDCs about 45% (P = 0·001) but not of mDC compared to baseline normoxia. Furthermore, we observed a significant increase of TNF-α about 340% (P = 0·03) and of IL-6 about 286% (P = 0·002). In cell culture experiments exposure of blood to hypoxia led to no significant changes in DCs, so that a direct cytotoxic effect was excluded. During hypoxia, we observed a transient increase in stromal-derived factor 1 (SDF-1) which is important for pDC tissue recruitment. We show a significant decrease in circulating pDCs during hypoxia in parallel to a pro-inflammatory response. Further studies are necessary to evaluate whether the decrease in circulating pDCs might be the result of an enhanced tissue recruitment. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

  4. Dendritic cells star in Vancouver

    OpenAIRE

    Klechevsky, Eynav; Kato, Hiroki; Sponaas, Anne-Marit

    2005-01-01

    The fast-moving field of dendritic cell (DC) biology is hard to keep pace with. Here we report on advances from the recent Keystone Symposium, “Dendritic Cells at the Center of Innate and Adaptive Immunity,” organized in Vancouver, BC on Feb. 1–7, 2005 by Anne O'Garra, Jacques Banchereau, and Alan Sher. New insights into the molecular mechanisms of DC function and their influence on immune regulation, their role in infectious and autoimmune disease, and new clinical applications are highlight...

  5. Alpha-defensins 1-3 release by dendritic cells is reduced by estrogen

    Directory of Open Access Journals (Sweden)

    Sperling Rhoda

    2011-08-01

    Full Text Available Abstract Background During pregnancy the immune system of the mother must protect any activation that may negatively affect the fetus. Changes in susceptibility to infection as well as resolution of some autoimmune disorders represent empirical evidence for pregnancy related alterations in immunity. Sex hormones reach extremely high levels during pregnancy and have been shown to have direct effects on many immune functions including the antiviral response of dendritic cells. Among the immunologically active proteins secreted by monocyte derived DCs (MDDC are the alpha-defensins 1-3. This family of cationic antimicrobial peptides has a broad spectrum of microbicidal activity and has also been shown to link innate to adaptive immunity by attracting T cells and immature DCs, which are essential for initiating and polarizing the immune response. Methods We compare culture-generated monocyte derived DCs (MDDCs with directly isolated myeloid dendritic cells (mDCs and plasmacytoid dendritic cells (pDCs and measure their alpha-defensins 1-3 secretion by ELISA both, in basal situations and after hormone (E2 or PG treatments. Moreover, using a cohort of pregnant women we isolated mDCs from blood and also measure the levels of these anti-microbial peptides along pregnancy. Results We show that mDCs and pDCs constitutively produce alpha-defensins 1-3 and at much higher levels than MDDCs. Alpha-defensins 1-3 production from mDCs and MDDCs but not pDCs is inhibited by E2. PG does not affect alpha-defensins 1-3 in any of the populations. Moreover, alpha-defensins 1-3 production by mDCs was reduced in the later stages of pregnancy in 40% of the patients. Conclusions Here, we demonstrate that mDCs and pDCs secrete alpha-defensins 1-3 and present a novel effect of E2 on the secretion of alpha-defensins 1-3 by dendritic cells.

  6. Bone marrow-derived dendritic cells.

    Science.gov (United States)

    Roney, Kelly

    2013-01-01

    While much is understood about dendritic cells and their role in the immune system, the study of these cells is critical to gain a more complete understanding of their function. Dendritic cell isolation from mouse body tissues can be difficult and the number of cells isolated small. This protocol describes the growth of large number of dendritic cells from the culture of mouse bone marrow cells. The dendritic cells grown in culture facilitate experiments that may require large number of dendritic cells without great expense or use of large number of mice.

  7. Phospholipid Scramblase 1 regulates Toll-like receptor 9-mediated type Ⅰ interferon production in plasmacytoid dendritic cells

    Institute of Scientific and Technical Information of China (English)

    Amjad H Talukder; Musheng Bao; Tae Whan Kim; Valeria Facchinetti; Shino Hanabuchi; Laura Bover; Tomasz Zal; Yong-Jun Liu

    2012-01-01

    Toll-like receptor 9 (TLR9) senses microbial DNA in the endosomes of plasmacytoid dendritic cells (pDCs) and triggers MyD88-dependent type 1 interferon (IFN) responses.To better understand TLR9 biology in pDCs,we established a yeast two-hybrid library for the identification of TLR9-interacting proteins.Here,we report that an IFN-inducible protein,phospholipid scramblase 1 (PLSCR1),interacts with TLR9 in pDCs.Knockdown of PLSCR1 expression by siRNA in human pDC cell line led to a 60-70% reduction of IFN-α responses following CpG-ODN (oligodeoxynucleotide) stimulation.Primary pDCs from PLSCR1-deficient mice produced lower amount of type 1 IFN than pDCs from the wild-type mice in response to CpG-ODN,herpes simplex virus and influenza A virus.Following CpG-A stimulation,there were much lower amounts of TLR9 in the early endosomes together with CpG-A in pDCs from PLSCRl-deficient mice.Our study demonstrates that PLSCR1 is a TLR9-interacting protein that plays an important role in pDC's type 1 IFN responses by regulating TLR9 trafficking to the endosomal compartment.

  8. A type I IFN–Flt3 ligand axis augments plasmacytoid dendritic cell development from common lymphoid progenitors

    Science.gov (United States)

    Chen, Yi-Ling; Chen, Ting-Ting; Pai, Li-Mei; Wesoly, Joanna; Bluyssen, Hans A.R.

    2013-01-01

    During infections and inflammation, plasmacytoid dendritic cells (pDCs) are the most potent type I interferon (IFN-I)–producing cells. However, the developmental origin of pDCs and the signals dictating pDC generation remain incompletely understood. Here, we report a synergistic role for IFN-I and Flt3 ligand (FL) in pDC development from common lymphoid progenitors (CLPs). Both conventional DCs (cDCs) and pDCs were generated from CLPs in response to FL, whereas pDC generation required higher concentrations of FL and concurrent IFN-I signaling. An absence of IFN-I receptor, impairment of IFN-I signaling, or neutralization of IFN-I significantly impeded pDC development from CLPs. Furthermore, FL induced IFN-I expression in CLPs, which in turn induced Flt3 up-regulation that facilitated survival and proliferation of CLPs, as well as their differentiation into pDCs. Collectively, these results define a critical role for the FL/IFN-I/Flt3 axis in pDC differentiation from CLPs. PMID:24145513

  9. RUNX2 Mediates Plasmacytoid Dendritic Cell Egress from the Bone Marrow and Controls Viral Immunity.

    Science.gov (United States)

    Chopin, Michaël; Preston, Simon P; Lun, Aaron T L; Tellier, Julie; Smyth, Gordon K; Pellegrini, Marc; Belz, Gabrielle T; Corcoran, Lynn M; Visvader, Jane E; Wu, Li; Nutt, Stephen L

    2016-04-13

    Plasmacytoid dendritic cells (pDCs) represent a unique immune cell type that responds to viral nucleic acids through the rapid production of type I interferons. Within the hematopoietic system, the transcription factor RUNX2 is exclusively expressed in pDCs and is required for their peripheral homeostasis. Here, we show that RUNX2 plays an essential role in promoting pDC localization and function. RUNX2 is required for the appropriate expression of the integrin-mediated adhesion machinery, as well as for the down-modulation of the chemokine receptor CXCR4, which allows pDC egress into the circulation. RUNX2 also facilitates the robust response to viral infection through the control of IRF7, the major regulator of type I interferon production. Mice lacking one copy of Runx2 have reduced numbers of peripheral pDCs and IFN-α expression, which might contribute to the reported difficulties of individuals with cleidocranial dysplasia, who are haploinsufficient for RUNX2, to clear viral infections.

  10. RUNX2 Mediates Plasmacytoid Dendritic Cell Egress from the Bone Marrow and Controls Viral Immunity

    Directory of Open Access Journals (Sweden)

    Michaël Chopin

    2016-04-01

    Full Text Available Plasmacytoid dendritic cells (pDCs represent a unique immune cell type that responds to viral nucleic acids through the rapid production of type I interferons. Within the hematopoietic system, the transcription factor RUNX2 is exclusively expressed in pDCs and is required for their peripheral homeostasis. Here, we show that RUNX2 plays an essential role in promoting pDC localization and function. RUNX2 is required for the appropriate expression of the integrin-mediated adhesion machinery, as well as for the down-modulation of the chemokine receptor CXCR4, which allows pDC egress into the circulation. RUNX2 also facilitates the robust response to viral infection through the control of IRF7, the major regulator of type I interferon production. Mice lacking one copy of Runx2 have reduced numbers of peripheral pDCs and IFN-α expression, which might contribute to the reported difficulties of individuals with cleidocranial dysplasia, who are haploinsufficient for RUNX2, to clear viral infections.

  11. Hepatitis C virus core protein inhibits interferon production by a human plasmacytoid dendritic cell line and dysregulates interferon regulatory factor-7 and signal transducer and activator of transcription (STAT 1 protein expression.

    Directory of Open Access Journals (Sweden)

    Amy E L Stone

    Full Text Available Plasmacytoid Dendritic Cells (pDCs represent a key immune cell population in the defense against viruses. pDCs detect viral pathogen associated molecular patterns (PAMPs through pattern recognition receptors (PRR. PRR/PAMP interactions trigger signaling events that induce interferon (IFN production to initiate local and systemic responses. pDCs produce Type I and Type III (IFNL IFNs in response to HCV RNA. Extracellular HCV core protein (Core is found in the circulation in chronic infection. This study defined how Core modulates PRR signaling in pDCs. Type I and III IFN expression and production following exposure to recombinant Core or β-galactosiade was assessed in human GEN2.2 cells, a pDC cell line. Core suppressed type I and III IFN production in response to TLR agonists and the HCV PAMP agonist of RIG-I. Core suppression of IFN induction was linked with decreased IRF-7 protein levels and increased non-phosphorylated STAT1 protein. Circulating Core protein interferes with PRR signaling by pDCs to suppress IFN production. Strategies to define and target Core effects on pDCs may serve to enhance IFN production and antiviral actions against HCV.

  12. Effect of plasma viremia on apoptosis and immunophenotype of dendritic cells subsets in acute SIVmac239 infection of Chinese rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Hou-Jun Xia

    Full Text Available Non-human primates such as Chinese rhesus macaques (Ch Rhs provide good animal models for research on human infectious diseases. Similar to humans, there are two principal subsets of dendritic cells (DCs in the peripheral blood of Ch Rhs: myeloid DCs (mDCs and plasmacytoid DCs (pDCs. In this study, two-color fluorescence-activated cell sorting (FACS analyses were used to identify the main DC subsets, namely CD1c(+ mDCs and pDCs from Ch Rhs. Then, the apoptosis and immunophenotype changes of DCs subsets were first described during the acute phase of SIVmac239 infection. Both the DCs subsets showed decreased CD4 expression and enhanced CCR5 expression; in particular, those of pDCs significantly changed at most time points. Interestingly, the plasma viral loads were negatively correlated with CD4 expression, but were positively correlated with CCR5 expression of pDCs. During this period, both CD1c(+ mDCs and pDCs were activated by enhancing expressions of co-stimulatory molecules, accompanied with increase in CCR7. Either CD80 or CD86 expressed on CD1c(+ mDCs and pDCs was positively correlated with the plasma viral loads. Our analysis demonstrates that the pDCs were more prone to apoptosis after infection during the acute phase of SIVmac239 infection, which may be due to their high expressions of CD4 and CCR5. Both DCs subsets activated through elevating the expression of co-stimulatory molecules, which was beneficial in controlling the replication of SIV. However, a mere broad immune activation initiated by activated DCs may lead to tragic AIDS progression.

  13. Dendritic cells and contact dermatitis.

    Science.gov (United States)

    Sasaki, Yoshinori; Aiba, Setsuya

    2007-10-01

    Contact dermatitis is a biological response to simple chemicals in the skin. Although it is well known that allergic contact dermatitis is mediated by the immune system, it is still uncertain whether it is a kind of protective response or it is simply an unnecessary response. We have demonstrated the following: (1) haptens activate Langerhans cells in the initiation phase of murine allergic contact dermatitis in vivo, (2) haptens activate human monocyte-derived dendritic cells in vitro, (3) the activation of dendritic cells by haptens is primarily mediated by the activation of p38 mitogen-activated protein kinase (MAPK), and (4) the activation of p38 MAPK is mediated by stimulation related to an imbalance of intracellular redox. Based on these observations, we will discuss the biological significance of contact dermatitis. In addition, we will review some up-to-date findings on Langerhans cell biology.

  14. Melanoma immunotherapy: dendritic cell vaccines

    OpenAIRE

    Lozada-Requena, Ivan; Laboratorios de Inmunología #108, Laboratorio de investigación y Desarrollo, Facultad de Ciencieas y Filosofía, Universidad Cayetano Heredia. Lima, Perú Empresa de Investigación y Desarrollo en Cáncer (EMINDES) SAC. Lima, Perú.; Núñez, César; Empresa de Investigación y Desarrollo en Cáncer (EMINDES) SAC. Lima, Perú.; Aguilar, José Luis; Laboratorios de Inmunología #108, Laboratorio de investigación y Desarrollo, Facultad de Ciencieas y Filosofía, Universidad Cayetano Heredia. Lima, Perú.

    2015-01-01

    This is a narrative review that shows accessible information to the scientific community about melanoma and immunotherapy.Dendritic cells have the ability to participate in innate and adaptive immunity, but are not unfamiliar to the immune evasion oftumors. Knowing the biology and role has led to generate in vitro several prospects of autologous cell vaccines against diversetypes of cancer in humans and animal models. However, given the low efficiency they have shown, we must implementstrateg...

  15. Plasmacytoid Dendritic Cells Producing Interferon-α (IFN-α) and Inducing Mx1 Play an Important Role for CD4(+) Cells and CD8(+) Cells in Necrotizing Lymphadenitis.

    Science.gov (United States)

    Sato, Hiroko; Asano, Shigeyuki; Mori, Kikuo; Yamazaki, Kazuki; Wakasa, Haruki

    2015-01-01

    We confirmed the characteristic clinical features of necrotizing lymphadenitis (NEL) in 66 cases (23 male, 43 female) in Japan, which included high fever (38-40°), painful cervical lymphadenopathy (62/66, 93.9%), and leukopenia (under 4,000/mm(3)) (25/53, 47.2%), without seasonal occurrence, in a clinicopathological, immunohistochemical, electron microscopic serological study. Patient age varied from 3-55 years, and 72.7% (44/66) of patients were younger than 30 years. Histopathology of NEL was characterized by the presence of CD8(+) immunoblasts, CD123(+) cells (plasmacytoid dendritic cells; PDCs), histiocytes and macrophages phagocytizing CD4(+) apoptotic lymphocytes, but no granulocytes or bacteria. The number of PDCs and CD8(+) cells in lesions tended to increase with time, and PDCs tended to be larger and irregular in the lesions compared with the non-lesion tissue of the lymph nodes. In addition, PDCs showed no temporal morphological change in the lymph nodes. The number of CD4(+) cells in the lymph node lesions sharply decreased from the 2nd to the 4th week, and then tended to increase; however, CD4(+) cells gradually decreased with time in non-lesion tissue. PDCs may produce interferon-α (IFN-α), which induces Mx1 expression. Strong Mx1 immunoreactivity is indicative of IFN-α production. IFN-α induces transformation of CD8(+) cells into immunoblasts, as well as phagocytosis of apoptotic cells derived from CD4(+) cells by macrophages. Thus, PDCs may play an important role with immune cells, including CD8(+) and CD4(+) cells, in necrotizing lymphadenitis.

  16. Plasmacytoid Dendritic Cells Act as the Most Competent Cell Type in Linking Antiviral Innate and Adaptive Immune Responses

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhang; Fu-Sheng Wang

    2005-01-01

    Appropriate in vivo control of plasmacytoid dendritic cell (pDC) recruitment and activation is a fundamental requirement for defense against viral infection. During this process, a pivotal event that influences the outcome of viral infection is the production of high levels of type I interferon by pDCs. In particular, recent research findings showed that pDCs not only shape the nature of innate resistance, but are also responsible for the successful transition from innate to adaptive immunity for viral resistance. In addition, pDCs can differentiate into antigen presenting cells that may regulate tolerance to a given pathogen. Importantly, in a series of recent clinical studies,pDCs appeared to be defective in number and function in conditions of chronic viral diseases such as infected with HIV-1, HBV or HCV. pDC-associated clinical antiviral therapy is also emerging. This review describes research findings exanining the functional and antiviral properties of in vivo pDC plasticity.

  17. The rapid and sustained responses of dendritic cells to influenza virus infection in a non-human primate model.

    Science.gov (United States)

    Jie, Zhijun; Sun, Wei; Wang, Shanze; Koster, Frederick; Li, Bilan; Harrod, Kevin S

    2014-01-01

    Dendritic cells (DCs) are readily infected by influenza viruses and play a crucial role in regulating host innate and adaptive immune responses to viral infection. The aims of this study are to characterize the dynamic changes in the numbers and maturation status of dendritic cells present in the lung and lung-associated lymph nodes (LALNs) in the model of a non-human primate (NHP) infected by influenza A virus (IAV). Cynomolgus macaques were infected with influenza A virus (H3N2) via bronchoscopy. Flow cytometry was used to analyze the DC numbers, maturation status and subsets during the time of acute infection (days 1, 2, 3, 4, 7) and the resolution phase (day 30). A dramatic increase in the numbers of influenza A virus-infected CD11c+CD14- myeloid dendritic cells (mDCs) and CD11c-CD123+ plasmacytoid dendritic cells (pDCs) were observed from day 1 to day 4 and peak up from day 7 post-infection. In lung and lung-associated lymph nodes, the numbers and maturation status of myeloid dendritic cells and plasmacytoid dendritic cells increased more slowly than those in the lung tissues. On day 30 post-infection, influenza A virus challenge increased the number of myeloid dendritic cells, but not plasmacytoid dendritic cells, compared with baseline. These findings indicate that dendritic cells are susceptible to influenza A virus infection, with the likely purpose of increasing mature myeloid dendritic cells numbers in the lung and lung and lung-associated lymph nodes, which provides important new insights into the regulation of dendritic cells in a non-human primate model.

  18. Dendritic Cells, New Tools for Vaccination

    Science.gov (United States)

    2003-01-01

    Review Dendritic cells , new tools for vaccination Jesus Colino, Clifford M. Snapper * Department of Pathology, Uniformed Services University of the...2003 Éditions scientifiques et médicales Elsevier SAS. All rights reserved. Keywords: Vaccines; Immunotherapy; Dendritic cells 1. Introduction During...DATE 2003 2. REPORT TYPE 3. DATES COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE Dendritic cells , new tools for vaccination 5a

  19. Neoplasms derived from plasmacytoid dendritic cells.

    Science.gov (United States)

    Facchetti, Fabio; Cigognetti, Marta; Fisogni, Simona; Rossi, Giuseppe; Lonardi, Silvia; Vermi, William

    2016-02-01

    Plasmacytoid dendritic cell neoplasms manifest in two clinically and pathologically distinct forms. The first variant is represented by nodular aggregates of clonally expanded plasmacytoid dendritic cells found in lymph nodes, skin, and bone marrow ('Mature plasmacytoid dendritic cells proliferation associated with myeloid neoplasms'). This entity is rare, although likely underestimated in incidence, and affects predominantly males. Almost invariably, it is associated with a myeloid neoplasm such as chronic myelomonocytic leukemia or other myeloid proliferations with monocytic differentiation. The concurrent myeloid neoplasm dominates the clinical pictures and guides treatment. The prognosis is usually dismal, but reflects the evolution of the associated myeloid leukemia rather than progressive expansion of plasmacytoid dendritic cells. A second form of plasmacytoid dendritic cells tumor has been recently reported and described as 'blastic plasmacytoid dendritic cell neoplasm'. In this tumor, which is characterized by a distinctive cutaneous and bone marrow tropism, proliferating cells derive from immediate CD4(+)CD56(+) precursors of plasmacytoid dendritic cells. The diagnosis of this form can be easily accomplished by immunohistochemistry, using a panel of plasmacytoid dendritic cells markers. The clinical course of blastic plasmacytoid dendritic cell neoplasm is characterized by a rapid progression to systemic disease via hematogenous dissemination. The genomic landscape of this entity is currently under intense investigation. Recurrent somatic mutations have been uncovered in different genes, a finding that may open important perspectives for precision medicine also for this rare, but highly aggressive leukemia.

  20. Dengue virus activates membrane TRAIL relocalization and IFN-α production by human plasmacytoid dendritic cells in vitro and in vivo.

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    Mariana Gandini

    Full Text Available BACKGROUND: Dengue displays a broad spectrum of clinical manifestations that may vary from asymptomatic to severe and even fatal features. Plasma leakage/hemorrhages can be caused by a cytokine storm induced by monocytes and dendritic cells during dengue virus (DENV replication. Plasmacytoid dendritic cells (pDCs are innate immune cells and in response to virus exposure secrete IFN-α and express membrane TRAIL (mTRAIL. We aimed to characterize pDC activation in dengue patients and their function under DENV-2 stimulation in vitro. METHODS FINDINGS: Flow cytometry analysis (FCA revealed that pDCs of mild dengue patients exhibit significantly higher frequencies of mTRAIL compared to severe cases or healthy controls. Plasma levels of IFN-α and soluble TRAIL are increased in mild compared to severe dengue patients, positively correlating with pDC activation. FCA experiments showed that in vitro exposure to DENV-2 induced mTRAIL expression on pDC. Furthermore, three dimension microscopy highlighted that TRAIL was relocalized from intracellular compartment to plasma membrane. Chloroquine treatment inhibited DENV-2-induced mTRAIL relocalization and IFN-α production by pDC. Endosomal viral degradation blockade by chloroquine allowed viral antigens detection inside pDCs. All those data are in favor of endocytosis pathway activation by DENV-2 in pDC. Coculture of pDC/DENV-2-infected monocytes revealed a dramatic decrease of antigen detection by FCA. This viral antigens reduction in monocytes was also observed after exogenous IFN-α treatment. Thus, pDC effect on viral load reduction was mainly dependent on IFN-α production. CONCLUSIONS: This investigation characterizes, during DENV-2 infection, activation of pDCs in vivo and their antiviral role in vitro. Thus, we propose TRAIL-expressing pDCs may have an important role in the outcome of disease.

  1. Specific roles for dendritic cell subsets during initiation and progression of psoriasis

    OpenAIRE

    Glitzner, Elisabeth; Korosec, Ana; Brunner, Patrick M.; Drobits, Barbara; Amberg, Nicole; Schonthaler, Helia B.; Kopp, Tamara; Wagner, Erwin F.; Stingl, Georg; Holcmann, Martin; Sibilia, Maria

    2014-01-01

    Several subtypes of APCs are found in psoriasis patients, but their involvement in disease pathogenesis is poorly understood. Here, we investigated the contribution of Langerhans cells (LCs) and plasmacytoid DCs (pDCs) in psoriasis. In human psoriatic lesions and in a psoriasis mouse model (DKO* mice), LCs are severely reduced, whereas pDCs are increased. Depletion of pDCs in DKO* mice prior to psoriasis induction resulted in a milder phenotype, whereas depletion during active disease had no ...

  2. Impaired interferon-alpha production by plasmacytoid dendritic cells after cord blood transplantation in children: implication for post-transplantation toll-like receptor ligand-based immunotherapy.

    Science.gov (United States)

    Charrier, Emily; Cordeiro, Paulo; Brito, Rose-Marie; Harnois, Michaël; Mezziani, Samira; Herblot, Sabine; Le Deist, Françoise; Duval, Michel

    2014-10-01

    Plasmacytoid dendritic cells (pDCs) initiate both innate and adaptive immune responses, making them attractive targets for post-transplantation immunotherapy, particularly after cord blood transplantation (CBT). Toll-like receptor (TLR) agonists are currently studied for pDC stimulation in various clinical settings. Their efficacy depends on pDC number and functionality, which are unknown after CBT. We performed a longitudinal study of pDC reconstitution in children who underwent bone marrow transplantation (BMT) and single-unit CBT. Both CBT and unrelated BMT patients received antithymocyte globulin as part of their graft-versus-host disease prophylaxis regimen. pDC blood counts were higher in CBT patients than in healthy volunteers from 2 to 9 months after transplantation, whereas they remained lower in BMT patients. We showed that cord blood progenitors gave rise in vitro to a 500-fold increase in functional pDCs over bone marrow counterparts. Upon stimulation with a TLR agonist, pDCs from both CBT and BMT recipients upregulated T cell costimulatory molecules, whereas interferon-alpha (IFN-α) production was impaired for 9 months after CBT. TLR agonist treatment is thus not expected to induce IFN-α production by pDCs after CBT, limiting its immunotherapeutic potential. Fortunately, in vitro production of large amounts of functional pDCs from cord blood progenitors paves the way for the post-transplantation adoptive transfer of pDCs. Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  3. Regulation of type I interferon responses by mitochondria-derived reactive oxygen species in plasmacytoid dendritic cells.

    Science.gov (United States)

    Agod, Zsofia; Fekete, Tünde; Budai, Marietta M; Varga, Aliz; Szabo, Attila; Moon, Hyelim; Boldogh, Istvan; Biro, Tamas; Lanyi, Arpad; Bacsi, Attila; Pazmandi, Kitti

    2017-10-01

    Mitochondrial reactive oxygen species (mtROS) generated continuously under physiological conditions have recently emerged as critical players in the regulation of immune signaling pathways. In this study we have investigated the regulation of antiviral signaling by increased mtROS production in plasmacytoid dendritic cells (pDCs), which, as major producers of type I interferons (IFN), are the key coordinators of antiviral immunity. The early phase of type I IFN production in pDCs is mediated by endosomal Toll-like receptors (TLRs), whereas the late phase of IFN response can also be triggered by cytosolic retinoic acid-inducible gene-I (RIG-I), expression of which is induced upon TLR stimulation. Therefore, pDCs provide an ideal model to study the impact of elevated mtROS on the antiviral signaling pathways initiated by receptors with distinct subcellular localization. We found that elevated level of mtROS alone did not change the phenotype and the baseline cytokine profile of resting pDCs. Nevertheless increased mtROS levels in pDCs lowered the TLR9-induced secretion of pro-inflammatory mediators slightly, whereas reduced type I IFN production markedly via blocking phosphorylation of interferon regulatory factor 7 (IRF7), the key transcription factor of the TLR9 signaling pathway. The TLR9-induced expression of RIG-I in pDCs was also negatively regulated by enhanced mtROS production. On the contrary, elevated mtROS significantly augmented the RIG-I-stimulated expression of type I IFNs, as well as the expression of mitochondrial antiviral-signaling (MAVS) protein and the phosphorylation of Akt and IRF3 that are essential components of RIG-I signaling. Collectively, our data suggest that increased mtROS exert diverse immunoregulatory functions in pDCs both in the early and late phase of type I IFN responses depending on which type of viral sensing pathway is stimulated. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Fate mapping of dendritic cells

    Directory of Open Access Journals (Sweden)

    Barbara Ursula Schraml

    2015-05-01

    Full Text Available Dendritic cells (DCs are a heterogeneous group of mononuclear phagocytes with versatile roles in immunity. They are classified predominantly based on phenotypic and functional properties, namely their stellate morphology, expression of the integrin CD11c and major histocompatibility class II molecules, as well as their superior capacity to migrate to secondary lymphoid organs and stimulate naïve T cells. However, these attributes are not exclusive to DCs and often change within inflammatory or infectious environments. This led to debates over cell identification and questioned even the mere existence of DCs as distinct leukocyte lineage. Here, we review experimental approaches taken to fate map DCs and discuss how these have shaped our understanding of DC ontogeny and lineage affiliation. Considering the ontogenetic properties of DCs will help to overcome the inherent shortcomings of purely phenotypic- and function-based approaches to cell definition and will yield a more robust way of DC classification.

  5. Attraction and activation of dendritic cells at the site of tumor elicits potent antitumor immunity.

    Science.gov (United States)

    Lapteva, Natalia; Aldrich, Melissa; Rollins, Lisa; Ren, Wenhong; Goltsova, Tatiana; Chen, Si-Yi; Huang, Xue F

    2009-09-01

    Tumor cells harbor unique genetic mutations, which lead to the generation of immunologically foreign antigenic peptide repertoire with the potential to induce individual tumor-specific immune responses. Here, we developed an in situ tumor vaccine with the ability to elicit antitumor immunity. This vaccine comprised an E1B-deleted oncolytic adenovirus expressing beta-defensin-2 (Ad-BD2-E1A) for releasing tumor antigens, recruiting and activating plasmacytoid dendritic cells (pDCs). Intratumoral injections of Ad-BD2-E1A vaccine inhibited primary breast tumor growth and blocked naturally occurring metastasis in mice. Ad-BD2-E1A vaccination induced potent tumor-specific T-cell responses. Splenic and intratumoral DCs isolated from Ad-BD2-E1A-immunized mice were able to stimulate or promote the differentiation of naive T cells into tumor-specific cytotoxic T cells. We further found that the increased numbers of mature CD45RA(+)CD8alpha(+)CD40(+) pDCs infiltrated into Ad-BD2-E1A-treated tumors. The antitumor effect of Ad-BD2-E1A vaccination was abrogated in toll-like receptor 4 (TLR4) deficient mice, suggesting the critical role of TLR4 in the induction of antitumor immunity by Ad-BD2-E1A. The results of this study indicate that in situ vaccination with the oncolytic BD2-expressing adenovirus preferentially attracts pDCs and promotes their maturation, and thus elicits potent tumor-specific immunity. This vaccine represents an attractive therapeutic strategy for the induction of individualized antitumor immunity.

  6. Gfi1 and gfi1b repress rag transcription in plasmacytoid dendritic cells in vitro.

    Directory of Open Access Journals (Sweden)

    Kwan T Chow

    Full Text Available Growth factor independence genes (Gfi1 and Gfi1b repress recombination activating genes (Rag transcription in developing B lymphocytes. Because all blood lineages originate from hematopoietic stem cells (HSCs and different lineage progenitors have been shown to share transcription factor networks prior to cell fate commitment, we hypothesized that GFI family proteins may also play a role in repressing Rag transcription or a global lymphoid transcriptional program in other blood lineages. We tested the level of Rag transcription in various blood cells when Gfi1 and Gfi1b were deleted, and observed an upregulation of Rag expression in plasmacytoid dendritic cells (pDCs. Using microarray analysis, we observed that Gfi1 and Gfi1b do not regulate a lymphoid or pDC-specific transcriptional program. This study establishes a role for Gfi1 and Gfi1b in Rag regulation in a non-B lineage cell type.

  7. A Case of Plasmacytoid Dendritic Cell Leukemia

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    Köpeczi Judit Beáta

    2013-04-01

    Full Text Available Introduction: Plasmacytoid dendritic cell leukemia is a rare subtype of acute leukemia, which has recently been established as a distinct pathologic entity that typically follows a highly aggressive clinical course in adults. The aim of this report is to present a case of plasmacytoid dendritic cell leukemia due to its rarity and difficulty to recognize and diagnose it.

  8. Dendritic web silicon for solar cell application

    Science.gov (United States)

    Seidensticker, R. G.

    1977-01-01

    The dendritic web process for growing long thin ribbon crystals of silicon and other semiconductors is described. Growth is initiated from a thin wirelike dendrite seed which is brought into contact with the melt surface. Initially, the seed grows laterally to form a button at the melt surface; when the seed is withdrawn, needlelike dendrites propagate from each end of the button into the melt, and the web portion of the crystal is formed by the solidification of the liquid film supported by the button and the bounding dendrites. Apparatus used for dendritic web growth, material characteristics, and the two distinctly different mechanisms involved in the growth of a single crystal are examined. The performance of solar cells fabricated from dendritic web material is indistinguishable from the performance of cells fabricated from Czochralski grown material.

  9. Dendritic Cells for Anomaly Detection

    CERN Document Server

    Greensmith, Julie; Aickelin, Uwe

    2010-01-01

    Artificial immune systems, more specifically the negative selection algorithm, have previously been applied to intrusion detection. The aim of this research is to develop an intrusion detection system based on a novel concept in immunology, the Danger Theory. Dendritic Cells (DCs) are antigen presenting cells and key to the activation of the human signals from the host tissue and correlate these signals with proteins know as antigens. In algorithmic terms, individual DCs perform multi-sensor data fusion based on time-windows. The whole population of DCs asynchronously correlates the fused signals with a secondary data stream. The behaviour of human DCs is abstracted to form the DC Algorithm (DCA), which is implemented using an immune inspired framework, libtissue. This system is used to detect context switching for a basic machine learning dataset and to detect outgoing portscans in real-time. Experimental results show a significant difference between an outgoing portscan and normal traffic.

  10. Dendritic cells in uninfected infants born to hepatitis B virus-positive mothers.

    Science.gov (United States)

    Koumbi, Lemonica J; Papadopoulos, Nikolaos G; Anastassiadou, Vassiliki; Machaira, Maria; Kafetzis, Dimitris A; Papaevangelou, Vassiliki

    2010-07-01

    Plasmacytoid dendritic cells (pDCs) play a central role in antiviral immunity, detecting viruses via Toll-like receptors (TLR) and producing in response vast amounts of type I interferons (IFNs). Hepatitis B virus (HBV) causes chronic infection after vertical transmission. This study investigated whether an HBV-infected maternal environment might influence DC numbers and pDC function in uninfected infants. Blood was collected from inactive HBsAg carrier and control mothers and their infants at birth and 1 and 6 months of age. HBV DNA was measured in maternal and neonatal perinatal sera using real-time PCR. The circulating frequencies of myeloid DCs (mDCs) and pDCs were determined in the babies by flow cytometry. Peripheral blood mononuclear cells (PBMCs) and cord blood pDCs were stimulated with resiquimod, and alpha interferon (IFN-alpha) production and the pDC phenotype were assessed. The effect of the common-cold virus, rhinovirus (RV), on resiquimod stimulation was also determined. HBV DNA was detected in 62.3% of the mothers and 41% of their infants. DC numbers and pDC functions were similar between subjects and controls and were not correlated with maternal or neonatal viremia. RV infection did not induce pDC maturation until the age of 6 months, and it reduced TLR7-dependent resiquimod-induced IFN-alpha production similarly in both groups. Although the DC system is immature at birth, DCs of uninfected neonates of HBV-positive mothers are competent to initiate and maintain T-cell responses. RV is a weak inducer of IFN-alpha production until the age of 6 months and inhibits IFN-alpha responses triggered by the TLR7 pathway.

  11. Relationships between IL-17(+) subsets, Tregs and pDCs that distinguish among SIV infected elite controllers, low, medium and high viral load rhesus macaques.

    Science.gov (United States)

    Khowawisetsut, Ladawan; Pattanapanyasat, Kovit; Onlamoon, Nattawat; Mayne, Ann E; Little, Dawn M; Villinger, Francois; Ansari, Aftab A

    2013-01-01

    Comprehensive studies of the frequencies and absolute numbers of the various cell lineages that synthesize IL-17 in the blood and corresponding gastrointestinal (GI) tissues, their correlation with CD4(+) Tregs, CD8(+) Tregs, total and IFN-α synthesizing plasmacytoid dendritic cells (pDC) relative to plasma viral load in SIV infection has been lacking. The unique availability of SIV infected rhesus macaques (RM) classified as Elite Controllers (EC), and those with Low, Intermediate and High Viral Loads (HVL) provided a unique opportunity to address this issue. Results of these studies showed that EC demonstrated a remarkable ability to reverse changes that are induced acutely by SIV in the various cell lineages. Highlights of the differences between EC and HVL RM within Gastro-intestinal tissues (GIT) was the maintenance and/or increases in the levels of IL-17 synthesizing CD4, CD8, and NK cells and pDCs associated with slight decreases in the levels of CD4(+) Tregs and IFN-α synthesizing pDCs in EC as compared with decreases in the levels of IL-17 synthesizing CD4, CD8 and NK cells associated with increases in pDCs and IFN-α synthesizing pDCs in HVL monkeys. A previously underappreciated role for CD8(+) Tregs was also noted with a moderate increase in ECs but further increases of CD8(+) Tregs with increasing VL in viremic monkeys. Positive correlations between plasma VL and decreases in the levels of Th17, Tc17, NK-17, CD4(+) Tregs and increases in the levels of CD8(+) Tregs, total and IFN-α synthesizing pDCs were also noted. This study also identified 2 additional IL-17(+) subsets in GIT as CD3(-/)CD8(+)/NKG2a(-) and CD3(+)/CD8(+)/NKG2a(+) subsets. Studies also suggest a limited role for IFN-α synthesizing pDCs in chronic immune activation despite persistent up-regulation of ISGs. Finally, elevated persistent innate immune responses appear associated with poor prognosis. These findings provide an initial foundation for markers important to follow for vaccine

  12. Relationships between IL-17(+ subsets, Tregs and pDCs that distinguish among SIV infected elite controllers, low, medium and high viral load rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Ladawan Khowawisetsut

    Full Text Available Comprehensive studies of the frequencies and absolute numbers of the various cell lineages that synthesize IL-17 in the blood and corresponding gastrointestinal (GI tissues, their correlation with CD4(+ Tregs, CD8(+ Tregs, total and IFN-α synthesizing plasmacytoid dendritic cells (pDC relative to plasma viral load in SIV infection has been lacking. The unique availability of SIV infected rhesus macaques (RM classified as Elite Controllers (EC, and those with Low, Intermediate and High Viral Loads (HVL provided a unique opportunity to address this issue. Results of these studies showed that EC demonstrated a remarkable ability to reverse changes that are induced acutely by SIV in the various cell lineages. Highlights of the differences between EC and HVL RM within Gastro-intestinal tissues (GIT was the maintenance and/or increases in the levels of IL-17 synthesizing CD4, CD8, and NK cells and pDCs associated with slight decreases in the levels of CD4(+ Tregs and IFN-α synthesizing pDCs in EC as compared with decreases in the levels of IL-17 synthesizing CD4, CD8 and NK cells associated with increases in pDCs and IFN-α synthesizing pDCs in HVL monkeys. A previously underappreciated role for CD8(+ Tregs was also noted with a moderate increase in ECs but further increases of CD8(+ Tregs with increasing VL in viremic monkeys. Positive correlations between plasma VL and decreases in the levels of Th17, Tc17, NK-17, CD4(+ Tregs and increases in the levels of CD8(+ Tregs, total and IFN-α synthesizing pDCs were also noted. This study also identified 2 additional IL-17(+ subsets in GIT as CD3(-/CD8(+/NKG2a(- and CD3(+/CD8(+/NKG2a(+ subsets. Studies also suggest a limited role for IFN-α synthesizing pDCs in chronic immune activation despite persistent up-regulation of ISGs. Finally, elevated persistent innate immune responses appear associated with poor prognosis. These findings provide an initial foundation for markers important to follow for vaccine

  13. A systems immunology approach to plasmacytoid dendritic cell function in cytopathic virus infections.

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    Gennady Bocharov

    Full Text Available Plasmacytoid dendritic cell (pDC-mediated protection against cytopathic virus infection involves various molecular, cellular, tissue-scale, and organism-scale events. In order to better understand such multiscale interactions, we have implemented a systems immunology approach focusing on the analysis of the structure, dynamics and operating principles of virus-host interactions which constrain the initial spread of the pathogen. Using high-resolution experimental data sets coming from the well-described mouse hepatitis virus (MHV model, we first calibrated basic modules including MHV infection of its primary target cells, i.e. pDCs and macrophages (Mphis. These basic building blocks were used to generate and validate an integrative mathematical model for in vivo infection dynamics. Parameter estimation for the system indicated that on a per capita basis, one infected pDC secretes sufficient type I IFN to protect 10(3 to 10(4 Mphis from cytopathic viral infection. This extremely high protective capacity of pDCs secures the spleen's capability to function as a 'sink' for the virus produced in peripheral organs such as the liver. Furthermore, our results suggest that the pDC population in spleen ensures a robust protection against virus variants which substantially down-modulate IFN secretion. However, the ability of pDCs to protect against severe disease caused by virus variants exhibiting an enhanced liver tropism and higher replication rates appears to be rather limited. Taken together, this systems immunology analysis suggests that antiviral therapy against cytopathic viruses should primarily limit viral replication within peripheral target organs.

  14. Dendritic cells are stressed out in tumor.

    Science.gov (United States)

    Maj, Tomasz; Zou, Weiping

    2015-09-01

    A recently paper published in Cell reports that dendritic cells (DCs) are dysfunctional in the tumor environment. Tumor impairs DC function through induction of endoplasmic reticulum stress response and subsequent disruption of lipid metabolic homeostasis.

  15. The role of plasmacytoid dendritic cells in liver diseases%浆细胞样树突状细胞在肝脏疾病中的作用

    Institute of Scientific and Technical Information of China (English)

    张新宁; 刘荣

    2014-01-01

    浆细胞样树突状细胞(pDCs)在外周血中所占比例很小,其选择性地表达Toll样受体 TLR7和 TLR9。pDCs 在接受病原体刺激后快速产生大量Ⅰ型干扰素,产生干扰素之后,pDCs通过激活传统树突状细胞、T细胞、自然杀伤细胞和B细胞形成保护性免疫反应,pDCs分化成为成熟树突状细胞,pDCs抗原提呈能力能够连接天然免疫和获得性免疫反应。已经有报道表明pDCs在病毒感染和癌症中发挥作用。本文中我们综述pDCs在肝脏疾病中的作用。%Plasmacytoid dendritic cells (pDCs) are a rare population of circulating cells that selectively express Toll-like receptors TLR7 and TLR9, they are specialized in rapid massive secretion of type Ⅰ interferon in response to pathogenic agents or danger signals. Through the production of type ⅠIFNs, pDCs initiate protective immunity by activating classical DCs, T cells, natural killer cells and B cells. Upon activation, pDCs differentiate into mature DCs. Combined with their antigen presentation capacity, this powerful functionality enables pDCs to orchestrate innate and adaptive immune responses. It has been demonstrated that pDCs can coordinate events during the course of viral infections and cancer. Here we reviewed select aspects of pDC biology involved in liver diseases.

  16. Anti-atherogenic peptide Ep1.B derived from apolipoprotein E induces tolerogenic plasmacytoid dendritic cells.

    Science.gov (United States)

    Bellemore, S M; Nikoopour, E; Au, B C Y; Krougly, O; Lee-Chan, E; Haeryfar, S M; Singh, B

    2014-09-01

    Tolerogenic dendritic cells (DCs) play a critical role in the induction of regulatory T cells (Tregs ), which in turn suppress effector T cell responses. We have previously shown the induction of DCs from human and mouse monocytic cell lines, mouse splenocytes and human peripheral blood monocytes by a novel apolipoprotein E (ApoE)-derived self-peptide termed Ep1.B. We also showed that this C-terminal region 239-252 peptide of ApoE has strong anti-atherogenic activity and reduces neointimal hyperplasia after vascular surgery in rats and wild-type as well as ApoE-deficient mice. In this study, we explored the phenotype of DC subset induced by Ep1.B from monocytic cell lines and from the bone marrow-derived cells. We found Ep1.B treatment induced cells that showed characteristics of plasmacytoid dendritic cells (pDC). We explored in-vitro and in-vivo effects of Ep1.B-induced DCs on antigen-specific T cell responses. Upon in-vivo injection of these cells with antigen, the subsequent ex-vivo antigen-specific proliferation of lymph node cells and splenocytes from recipient mice was greatly reduced. Our results suggest that Ep1.B-induced pDCs promote the generation of Treg cells, and these cells contribute to the induction of peripheral tolerance in adaptive immunity and potentially contribute its anti-atherogenic activity.

  17. Distinct Functions of Specialized Dendritic Cell Subsets in Atherosclerosis and the Road Ahead

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    Alma Zernecke

    2014-01-01

    Full Text Available Atherosclerotic vascular disease is modulated by immune mechanisms. Dendritic cells (DCs and T cells are present within atherosclerotic lesions and function as central players in the initiation and modulation of adaptive immune responses. In previous years, we have studied the functional contribution of distinct DC subsets in disease development, namely, that of CCL17-expressing DCs as well as that of plasmacytoid DCs that play specialized roles in disease development. This review focuses on important findings gathered in these studies and dissects the multifaceted contribution of CCL17-expressing DCs and pDCs to the pathogenesis of atherosclerosis. Furthermore, an outlook on future challenges faced when studying DCs in this detrimental disease are provided, and hurdles that will need to be overcome in order to enable a better understanding of the contribution of DCs to atherogenesis are discussed, a prerequisite for their therapeutic targeting in atherosclerosis.

  18. Evidence for local dendritic cell activation in pulmonary sarcoidosis

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    Berge Bregje

    2012-04-01

    Full Text Available Abstract Background Sarcoidosis is a granulomatous disease characterized by a seemingly exaggerated immune response against a difficult to discern antigen. Dendritic cells (DCs are pivotal antigen presenting cells thought to play an important role in the pathogenesis. Paradoxically, decreased DC immune reactivity was reported in blood samples from pulmonary sarcoidosis patients. However, functional data on lung DCs in sarcoidosis are lacking. We hypothesized that at the site of disease DCs are mature, immunocompetent and involved in granuloma formation. Methods We analyzed myeloid DCs (mDCs and plasmacytoid DCs (pDCs in broncho-alveolar lavage (BAL and blood from newly diagnosed, untreated pulmonary sarcoidosis patients and healthy controls using 9-color flowcytometry. DCs, isolated from BAL using flowcytometric sorting (mDCs or cultured from monocytes (mo-DCs, were functionally assessed in a mixed leukocyte reaction with naïve allogeneic CD4+ T cells. Using Immunohistochemistry, location and activation status of CD11c+DCs was assessed in mucosal airway biopsies. Results mDCs in BAL, but not in blood, from sarcoidosis patients were increased in number when compared with mDCs from healthy controls. mDCs purified from BAL of sarcoidosis patients induced T cell proliferation and differentiation and did not show diminished immune reactivity. Mo-DCs from patients induced increased TNFα release in co-cultures with naïve allogeneic CD4+ T cells. Finally, immunohistochemical analyses revealed increased numbers of mature CD86+ DCs in granuloma-containing airway mucosal biopsies from sarcoidosis patients. Conclusion Taken together, these finding implicate increased local DC activation in granuloma formation or maintenance in pulmonary sarcoidosis.

  19. Targeting vaccines to dendritic cells.

    Science.gov (United States)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-03-01

    Dendritic cells (DC) are specialized antigen presenting cells (APC) with a remarkable ability to take up antigens and stimulate major histocompatibility complex (MHC)-restricted specific immune responses. Recent discoveries have shown that their role in initiating primary immune responses seems to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC are considered to play a central role for the provocation of primary immune responses by vaccination. A rational way of improving the potency and safety of new and already existing vaccines could therefore be to direct vaccines specifically to DC. There is a need for developing multifunctional vaccine drug delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC.

  20. Artificial Dendritic Cells: Multi-faceted Perspectives

    CERN Document Server

    Greensmith, Julie

    2009-01-01

    Dendritic cells are the crime scene investigators of the human immune system. Their function is to correlate potentially anomalous invading entities with observed damage to the body. The detection of such invaders by dendritic cells results in the activation of the adaptive immune system, eventually leading to the removal of the invader from the host body. This mechanism has provided inspiration for the development of a novel bio-inspired algorithm, the Dendritic Cell Algorithm. This algorithm processes information at multiple levels of resolution, resulting in the creation of information granules of variable structure. In this chapter we examine the multi-faceted nature of immunology and how research in this field has shaped the function of the resulting Dendritic Cell Algorithm. A brief overview of the algorithm is given in combination with the details of the processes used for its development. The chapter is concluded with a discussion of the parallels between our understanding of the human immune system a...

  1. A Druggable TCF4- and BRD4-Dependent Transcriptional Network Sustains Malignancy in Blastic Plasmacytoid Dendritic Cell Neoplasm.

    Science.gov (United States)

    Ceribelli, Michele; Hou, Zhiying Esther; Kelly, Priscilla N; Huang, Da Wei; Wright, George; Ganapathi, Karthik; Evbuomwan, Moses O; Pittaluga, Stefania; Shaffer, Arthur L; Marcucci, Guido; Forman, Stephen J; Xiao, Wenming; Guha, Rajarshi; Zhang, Xiaohu; Ferrer, Marc; Chaperot, Laurence; Plumas, Joel; Jaffe, Elaine S; Thomas, Craig J; Reizis, Boris; Staudt, Louis M

    2016-11-14

    Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive and largely incurable hematologic malignancy originating from plasmacytoid dendritic cells (pDCs). Using RNAi screening, we identified the E-box transcription factor TCF4 as a master regulator of the BPDCN oncogenic program. TCF4 served as a faithful diagnostic marker of BPDCN, and its downregulation caused the loss of the BPDCN-specific gene expression program and apoptosis. High-throughput drug screening revealed that bromodomain and extra-terminal domain inhibitors (BETis) induced BPDCN apoptosis, which was attributable to disruption of a BPDCN-specific transcriptional network controlled by TCF4-dependent super-enhancers. BETis retarded the growth of BPDCN xenografts, supporting their clinical evaluation in this recalcitrant malignancy.

  2. Plasmacytoid Dendritic Cell Activation and IFN-α Production Are Prominent Features of Murine Autoimmune Pancreatitis and Human IgG4-Related Autoimmune Pancreatitis.

    Science.gov (United States)

    Arai, Yasuyuki; Yamashita, Kouhei; Kuriyama, Katsutoshi; Shiokawa, Masahiro; Kodama, Yuzo; Sakurai, Toshiharu; Mizugishi, Kiyomi; Uchida, Kazushige; Kadowaki, Norimitsu; Takaori-Kondo, Akifumi; Kudo, Masatoshi; Okazaki, Kazuichi; Strober, Warren; Chiba, Tsutomu; Watanabe, Tomohiro

    2015-10-01

    The abnormal immune response accompanying IgG4-related autoimmune pancreatitis (AIP) is presently unclear. In this study, we examined the role of plasmacytoid dendritic cell (pDC) activation and IFN-α production in this disease as well as in a murine model of AIP (MRL/Mp mice treated with polyinosinic-polycytidylic acid). We found that the development of AIP in treated MRL/Mp mice occurred in parallel with pancreatic accumulation of pDCs producing IFN-α, and with pDC depletion and IFN-α-blocking studies, we showed that such accumulation was necessary for AIP induction. In addition, we found that the pancreas of treated MRL/Mp mice contained neutrophil extracellular traps (NETs) shown previously to stimulate pDCs to produce IFN-α. Consistent with these findings, we found that patients with IgG4-related AIP also exhibited pancreatic tissue localization of IFN-α-expressing pDCs and had significantly higher serum IFN-α levels than healthy controls. In addition, the inflamed pancreas of these patients but not controls also contained NETs that were shown to be capable of pDC activation. More importantly, patient pDCs cultured in the presence of NETs produced greatly increased levels of IFN-α and induced control B cells to produce IgG4 (but not IgG1) as compared with control pDCs. These data suggest that pDC activation and production of IFN-α is a major cause of murine AIP; in addition, the increased pDC production of IFN-α and its relation to IgG4 production observed in IgG4-related AIP suggest that this mechanism also plays a role in the human disease.

  3. TLR7/TLR8 Activation Restores Defective Cytokine Secretion by Myeloid Dendritic Cells but Not by Plasmacytoid Dendritic Cells in HIV-Infected Pregnant Women and Newborns

    Science.gov (United States)

    Cardoso, Elaine Cristina; Pereira, Nátalli Zanete; Mitsunari, Gabrielle Eimi; Oliveira, Luanda Mara da Silva; Ruocco, Rosa Maria S. A.; Francisco, Rossana Pulcineli Vieira; Zugaib, Marcelo; da Silva Duarte, Alberto José; Sato, Maria Notomi

    2013-01-01

    Mother-to-child transmission (MTCT) of HIV-1 has been significantly reduced with the use of antiretroviral therapies, resulting in an increased number of HIV-exposed uninfected infants. The consequences of HIV infection on the innate immune system of both mother-newborn are not well understood. In this study, we analyzed peripheral blood and umbilical cord blood (CB) collected from HIV-1-infected and uninfected pregnant women. We measured TNF-α, IL-10 and IFN-α secretion after the stimulation of the cells with agonists of both extracellular Toll-like receptors (TLRs) (TLR2, TLR4 and TLR5) and intracellular TLRs (TLR7, TLR7/8 and TLR9). Moreover, as an indicator of the innate immune response, we evaluated the responsiveness of myeloid dendritic cells (mDCs) and plasmacytoid DCs (pDCs) to TLRs that are associated with the antiviral response. Our results showed that peripheral blood mononuclear cells (PBMCs) from HIV-1-infected mothers and CB were defective in TNF-α production after activation by TLR2, TLR5, TLR3 and TLR7. However, the TNF-α response was preserved after TLR7/8 (CL097) stimulation, mainly in the neonatal cells. Furthermore, only CL097 activation was able to induce IL-10 and IFN-α secretion in both maternal and CB cells in the infected group. An increase in IFN-α secretion was observed in CL097-treated CB from HIV-infected mothers compared with control mothers. The effectiveness of CL097 stimulation was confirmed by observation of similar mRNA levels of interferon regulatory factor-7 (IRF-7), IFN-α and TNF-α in PBMCs of both groups. The function of both mDCs and pDCs was markedly compromised in the HIV-infected group, and although TLR7/TLR8 activation overcame the impairment in TNF-α secretion by mDCs, such stimulation was unable to reverse the dysfunctional type I IFN response by pDCs in the HIV-infected samples. Our findings highlight the dysfunction of innate immunity in HIV-infected mother-newborn pairs. The activation of the TLR7/8 pathway

  4. Impaired blood dendritic cell numbers and functions after aneurysmal subarachnoid hemorrhage.

    Directory of Open Access Journals (Sweden)

    Antoine Roquilly

    Full Text Available PREVIOUS PRESENTATION: Portions of this study were presented at the Annual Congress of Société Française d'Anesthésie et de Réanimation in Paris, September 2012. BACKGROUND: Toll-like receptor (TLR agonists are promising therapy for the prevention of nosocomial infections in critical ill patients. We aimed to analyze the TLR-reactivity of circulating dendritic cells (DC as assessed by cytokine production after an ex vivo challenge with TLR agonists in aneurysmal subarachnoid hemorrhage (SAH patients. METHODS AND FINDINGS: A single-center prospective observational study took place in one intensive care unit of a teaching hospital. Blood samples were harvested on days 2, 5 and 10 in 21 severe SAH patients requiring mechanical ventilation and 17 healthy controls. DC production of cytokines (Tumour Necrosis Factor, TNF-α; Interleukin, IL-12; and Interferon, IFN-α was assessed by intracellular immunostaining on TLR-3, 4, 7/8 and 9 stimulations. SAH patients had decreased numbers of blood myeloid (mDCs and plasmacytoid DCs (pDCs on days 2, 5 and 10. Compared with the healthy controls, the frequency of mDCs producing TNF-α after TLR-3 stimulation was decreased in the SAH patients. The frequency of myeloid DCs producing IL-12 after TLR-3 and 4 stimulations was also decreased in the SAH patients. In contrast, the mDCs response to TLR-7/8 was not impaired in the SAH patients. The frequency of pDCs producing TNF-α(+ and IFN-α(+ on TLR-7/8 stimulation were reduced at all of the tested times in the SAH patients, whereas reactivity to TLR-9 was preserved. On day 2, the pDCs from non-survivor patients (n=8 had a decreased ability to produce IFN-α on TLR-9 stimulation compared with the survivors. CONCLUSIONS: These data suggest functional abnormalities of circulating pDCs and mDCs that could be important for immunomodulation after SAH.

  5. Dendritic cells in melanoma - immunohistochemical study and research trends.

    Science.gov (United States)

    Nedelcu, Roxana Ioana; Ion, Daniela Adriana; Holeab, Cosmin Adrian; Cioplea, Mirela Daniela; Brînzea, Alice; Zurac, Sabina Andrada

    2015-01-01

    Cutaneous dendritic cells play multiple physiological roles and are involved in various pathophysiological processes. Research studies of dendritic cells abound in the medical literature. Nevertheless, the role of dendritic cells in melanoma regression phenomenon is not completely understood. We conducted a scientometric analysis in order to highlight the current state on research regarding dendritic cells and melanoma. We also performed an immunohistochemical study, using specific markers for dendritic cells (CD1a, langerin). We evaluated the frequency and distribution of dendritic cells in areas of tumor regression compared to the areas of inflammatory infiltrate of melanoma without regression. The immunohistochemical study we performed revealed that dendritic cells are more frequent in the regressed areas, comparing with non-regressed ones. In regressed areas, dendritic cells have a predominant nodular pattern (19 cases), followed by diffuse isolate pattern (eight cases) and mixed pattern (diffuse and nodular) (three cases). In melanoma without regression, most cases presented a diffuse pattern (27 cases) of dendritic cells distribution. In conclusion, our immunohistochemical study stressed differences between frequency and distribution of dendritic cells located in the melanoma with regression and melanoma without regression. These data suggest that dendritic cells are involved in the regression phenomenon. Following the literature analysis we obtained, we observed that dendritic cells profile in melanoma with regression was poorly studied. Insights into antitumor immune response and dendritic cells may be essential for the understanding of the potential prognostic role of dendritic cells in melanoma and for the development of new promising therapeutic strategies for melanoma.

  6. HIV-1-triggered release of type I IFN by plasmacytoid dendritic cells induces BAFF production in monocytes.

    Science.gov (United States)

    Gomez, Alejandro M; Ouellet, Michel; Tremblay, Michel J

    2015-03-01

    HIV-1 infection leads to numerous B cell abnormalities, including hypergammaglobulinemia, nonspecific B cell activation, nonspecific class switching, increased cell turnover, breakage of tolerance, increased immature/transitional B cells, B cell malignancies, as well as a loss of capacity to generate and maintain memory, all of which contribute to a global impairment of the immune humoral compartment. Several cytokines and soluble factors, which are increased in sera of HIV-1-infected individuals, have been suggested to directly or indirectly contribute to these B cell dysfunctions, and one of these is the B cell-activating factor (BAFF). We report in this study that HIV-1 (X4- and R5-tropic) upregulates BAFF expression and secretion by human monocytes. Moreover, we show that the virus-mediated production of BAFF by monocytes relies on a type I IFN response by a small percentage of plasmacytoid dendritic cells (pDCs) present in the monocyte cultures. HIV-1-induced type I IFN by pDCs triggers BAFF production in both classical and intermediate monocytes, but not in nonclassical monocytes, which nonetheless display a very strong basal BAFF production. We report also that basal BAFF secretion was higher in monocytes obtained from females compared with those from male donors. This study provides a novel mechanistic explanation for the increased BAFF levels observed during HIV-1 infection and highlights the importance of pDC/monocyte crosstalk to drive BAFF secretion. Copyright © 2015 by The American Association of Immunologists, Inc.

  7. The role of dendritic cells in cancer

    DEFF Research Database (Denmark)

    Hansen, Morten; Andersen, Mads Hald

    2017-01-01

    Though present in low numbers, dendritic cells (DCs) are recognized as major players in the control of cancer by adaptive immunity. The roles of cytotoxic CD8+ T-cells and Th1 helper CD4+ T-cells are well-documented in murine models of cancer and associated with a profound prognostic impact when...... treatment regimens against cancer....

  8. Dendritic cells in peripheral tolerance and immunity

    DEFF Research Database (Denmark)

    Gad, Monika; Claesson, Mogens Helweg; Pedersen, Anders Elm

    2003-01-01

    Dendritic cells capable of influencing immunity exist as functionally distinct subsets, T cell-tolerizing and T cell-immunizing subsets. The present paper reviews how these subsets of DCs develop, differentiate and function in vivo and in vitro at the cellular and molecular level. In particular...

  9. Reduced Dendritic Cells Expressing CD200R1 in Children with Inflammatory Bowel Disease: Correlation with Th17 and Regulatory T Cells.

    Science.gov (United States)

    Elshal, Mohamed F; Aldahlawi, Alia M; Saadah, Omar I; McCoy, J Philip

    2015-12-04

    Loss of tolerance of the adaptive immune system towards indigenous flora contributes to the development of inflammatory bowel diseases (IBD). Defects in dendritic cell (DC)-mediated innate and adoptive immune responses are conceivable. The aim of this study was to investigate the expression of the inhibitory molecules CD200R1 and their ligand CD200 on DCs, to clarify the role of the DCs in the pathogenesis of IBD. Thirty-seven pediatric IBD patients (23 with Crohn's disease (CD) and 14 with ulcerative colitis (UC)) with mean age 13.25 ± 2.9 years were included. Fourteen age-matched healthy pediatric volunteers (five males and nine females) served as a control group (HC). The percentage of CD11c⁺ myeloid dendritic cells (mDCs) and CD123⁺ plasmacytoid DCs (pDCs) expressing CD200R1 and CD200 were evaluated in peripheral blood using flow cytometry and were correlated with routine biochemical, serological markers, serum levels of cytokines and with the percentages of circulating regulatory T cells (Treg) and CD4⁺ producing IL-17 (Th17). IBD patients showed a significant decrease in the percentage of pDCs and mDCs expressing CD200R1 compared to that of HC. Patients with UC showed increased expressions of the CD200 molecule on pDCs as compared to HC. DCs expressing CD200R1 were found to be correlated positively with Treg and negatively with TH17 and erythrocyte sedimentation rate (ESR). Our findings suggest that IBD is associated with dysregulation in the CD200R1/CD200 axis and that the decrease in DCs expressing CD200R1 may contribute to the imbalance of Th17 and Treg cells and in the pathogenesis of IBD.

  10. Dendritic Cells Stimulated by Cationic Liposomes.

    Science.gov (United States)

    Vitor, Micaela Tamara; Bergami-Santos, Patrícia Cruz; Cruz, Karen Steponavicius Piedade; Pinho, Mariana Pereira; Barbuto, José Alexandre Marzagão; De La Torre, Lucimara Gaziola

    2016-01-01

    Immunotherapy of cancer aims to harness the immune system to detect and destroy cancer cells. To induce an immune response against cancer, activated dendritic cells (DCs) must present tumor antigens to T lymphocytes of patients. However, cancer patients' DCs are frequently defective, therefore, they are prone to induce rather tolerance than immune responses. In this context, loading tumor antigens into DCs and, at the same time, activating these cells, is a tempting goal within the field. Thus, we investigated the effects of cationic liposomes on the DCs differentiation/maturation, evaluating their surface phenotype and ability to stimulate T lymphocytes proliferation in vitro. The cationic liposomes composed by egg phosphatidylcholine, 1,2-dioleoyl-3-trimethylammonium propane and 1,2-dioleoylphosphatidylethanolamine (50/25/25% molar) were prepared by the thin film method followed by extrusion (65 nm, polydispersity of 0.13) and by the dehydration-rehydration method (95% of the population 107 nm, polydispersity of 0.52). The phenotypic analysis of dendritic cells and the analysis of T lymphocyte proliferation were performed by flow cytometry and showed that both cationic liposomes were incorporated and activated dendritic cells. Extruded liposomes were better incorporated and induced higher CD86 expression for dendritic cells than dehydrated-rehydrated vesicles. Furthermore, dendritic cells which internalized extruded liposomes also provided stronger T lymphocyte stimulation. Thus, cationic liposomes with a smaller size and polydispersity seem to be better incorporated by dendritic cells. Hence, these cationic liposomes could be used as a potential tool in further cancer immunotherapy strategies and contribute to new strategies in immunotherapy.

  11. Detecting Danger: The Dendritic Cell Algorithm

    CERN Document Server

    Greensmith, Julie; Cayzer, Steve

    2010-01-01

    The Dendritic Cell Algorithm (DCA) is inspired by the function of the dendritic cells of the human immune system. In nature, dendritic cells are the intrusion detection agents of the human body, policing the tissue and organs for potential invaders in the form of pathogens. In this research, and abstract model of DC behaviour is developed and subsequently used to form an algorithm, the DCA. The abstraction process was facilitated through close collaboration with laboratory- based immunologists, who performed bespoke experiments, the results of which are used as an integral part of this algorithm. The DCA is a population based algorithm, with each agent in the system represented as an 'artificial DC'. Each DC has the ability to combine multiple data streams and can add context to data suspected as anomalous. In this chapter the abstraction process and details of the resultant algorithm are given. The algorithm is applied to numerous intrusion detection problems in computer security including the detection of p...

  12. ISOLATION OF CHICKEN FOLLICULAR DENDRITIC CELLS

    Science.gov (United States)

    The aim of the present study was to isolate chicken follicular dendritic cells (FDC). A combination of methods involving panning, iodixanol density gradient centrifugation, and magnetic cell separation technology made it possible to obtain functional FDC from the cecal tonsils from chickens, which h...

  13. Infection of Dendritic Cells by the Maedi-Visna Lentivirus

    OpenAIRE

    Ryan, Susanna; Tiley, Laurence; McConnell, Ian; Blacklaws, Barbara

    2000-01-01

    The early stages of lentivirus infection of dendritic cells have been studied in an in vivo model. Maedi-visna virus (MVV) is a natural pathogen of sheep with a tropism for macrophages, but the infection of dendritic cells has not been proven, largely because of the difficulties of definitively distinguishing the two cell types. Afferent lymphatic dendritic cells from sheep have been phenotypically characterized and separated from macrophages. Dendritic cells purified from experimentally infe...

  14. In Situ Observation of Cell-to-Dendrite Transition

    Institute of Scientific and Technical Information of China (English)

    PAN Xiu-Hong; HONG Yong; JIN Wei-Qing

    2005-01-01

    @@ The cell-to-dendrite transition of succinonitrile melt suspended on a loop-shaped Pt heater is observed in real time by a differential interference microscope coupled with Schlieren technique. The transition is divided into two parts: a dendrite coalition process and a subsequent dendrite elimination process. Firstly the dendrites from the same cell are united into a single dendrite. Secondly the competitive growth of dendrites from different cells leads to the elimination of dendrites. The two processes can be understood when involving crystallographic orientation. In addition, the tip velocity and primary spacing of a cell/dendrite are also measured. It turns out that the primary spacing has a significant jump, whereas the growth velocity has no abrupt change during the cell-to-dendrite transition.

  15. Plasmacytoid dendritic cells promote HIV-1-induced group 3 innate lymphoid cell depletion.

    Science.gov (United States)

    Zhang, Zheng; Cheng, Liang; Zhao, Juanjuan; Li, Guangming; Zhang, Liguo; Chen, Weiwei; Nie, Weiming; Reszka-Blanco, Natalia J; Wang, Fu-Sheng; Su, Lishan

    2015-09-01

    Group 3 innate lymphoid cells (ILC3s) have demonstrated roles in promoting antibacterial immunity, maintaining epithelial barrier function, and supporting tissue repair. ILC3 alterations are associated with chronic inflammation and inflammatory disease; however, the characteristics and relevant regulatory mechanisms of this cell population in HIV-1 infection are poorly understood due in part to a lack of a robust model. Here, we determined that functional human ILC3s develop in lymphoid organs of humanized mice and that persistent HIV-1 infection in this model depletes ILC3s, as observed in chronic HIV-1-infected patients. In HIV-1-infected mice, effective antiretroviral therapy reversed the loss of ILC3s. HIV-1-dependent reduction of ILC3s required plasmacytoid dendritic cells (pDCs), IFN-I, and the CD95/FasL pathway, as targeted depletion or blockade of these prevented HIV-1-induced ILC3 depletion in vivo and in vitro, respectively. Finally, we determined that HIV-1 infection induces CD95 expression on ILC3s via a pDC- and IFN-I-dependent mechanism that sensitizes ILC3s to undergo CD95/FasL-mediated apoptosis. We conclude that chronic HIV-1 infection depletes ILC3s through pDC activation, induction of IFN-I, and CD95-mediated apoptosis.

  16. Macrophages, Dendritic Cells, and Regression of Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Jonathan E. Feig

    2012-07-01

    Full Text Available Atherosclerosis is the number one cause of death in the Western world. It results from the interaction between modified lipoproteins and monocyte-derived cells such as macrophages, dendritic cells, T cells, and other cellular elements of the arterial wall. This inflammatory process can ultimately lead to the development of complex lesions, or plaques, that protrude into the arterial lumen. Ultimately, plaque rupture and thrombosis can occur leading to the clinical complications of myocardial infarction or stroke. Although each of the cell types plays roles in the pathogenesis of atherosclerosis, in this review, the focus will be primarily on the monocyte derived cells- macrophages and dendritic cells. The roles of these cell types in atherogenesis will be highlighted. Finally, the mechanisms of atherosclerosis regression as it relates to these cells will be discussed.

  17. Modification of host dendritic cells by microchimerism-derived extracellular vesicles generates split tolerance

    Science.gov (United States)

    Bracamonte-Baran, William; Florentin, Jonathan; Zhou, Ying; Jankowska-Gan, Ewa; Haynes, W. John; Zhong, Weixiong; Brennan, Todd V.; Dutta, Partha; Claas, Frans H. J.; van Rood, Jon J.; Burlingham, William J.

    2017-01-01

    Maternal microchimerism (MMc) has been associated with development of allospecific transplant tolerance, antitumor immunity, and cross-generational reproductive fitness, but its mode of action is unknown. We found in a murine model that MMc caused exposure to the noninherited maternal antigens in all offspring, but in some, MMc magnitude was enough to cause membrane alloantigen acquisition (mAAQ; “cross-dressing”) of host dendritic cells (DCs). Extracellular vesicle (EV)-enriched serum fractions from mAAQ+, but not from non-mAAQ, mice reproduced the DC cross-dressing phenomenon in vitro. In vivo, mAAQ was associated with increased expression of immune modulators PD-L1 (programmed death-ligand 1) and CD86 by myeloid DCs (mDCs) and decreased presentation of allopeptide+self-MHC complexes, along with increased PD-L1, on plasmacytoid DCs (pDCs). Remarkably, both serum EV-enriched fractions and membrane microdomains containing the acquired MHC alloantigens included CD86, but completely excluded PD-L1. In contrast, EV-enriched fractions and microdomains containing allopeptide+self-MHC did not exclude PD-L1. Adoptive transfer of allospecific transgenic CD4 T cells revealed a “split tolerance” status in mAAQ+ mice: T cells recognizing intact acquired MHC alloantigens proliferated, whereas those responding to allopeptide+self-MHC did not. Using isolated pDCs and mDCs for in vitro culture with allopeptide+self-MHC–specific CD4 T cells, we could replicate their normal activation in non-mAAQ mice, and PD-L1–dependent anergy in mAAQ+ hosts. We propose that EVs provide a physiologic link between microchimerism and split tolerance, with implications for tumor immunity, transplantation, autoimmunity, and reproductive success. PMID:28096390

  18. Differentiation of apical and basal dendrites in pyramidal cells and granule cells in dissociated hippocampal cultures.

    Science.gov (United States)

    Wu, You Kure; Fujishima, Kazuto; Kengaku, Mineko

    2015-01-01

    Hippocampal pyramidal cells and dentate granule cells develop morphologically distinct dendritic arbors, yet also share some common features. Both cell types form a long apical dendrite which extends from the apex of the cell soma, while short basal dendrites are developed only in pyramidal cells. Using quantitative morphometric analyses of mouse hippocampal cultures, we evaluated the differences in dendritic arborization patterns between pyramidal and granule cells. Furthermore, we observed and described the final apical dendrite determination during dendritic polarization by time-lapse imaging. Pyramidal and granule cells in culture exhibited similar dendritic patterns with a single principal dendrite and several minor dendrites so that the cell types were not readily distinguished by appearance. While basal dendrites in granule cells are normally degraded by adulthood in vivo, cultured granule cells retained their minor dendrites. Asymmetric growth of a single principal dendrite harboring the Golgi was observed in both cell types soon after the onset of dendritic growth. Time-lapse imaging revealed that up until the second week in culture, final principal dendrite designation was not stabilized, but was frequently replaced by other minor dendrites. Before dendritic polarity was stabilized, the Golgi moved dynamically within the soma and was repeatedly repositioned at newly emerging principal dendrites. Our results suggest that polarized growth of the apical dendrite is regulated by cell intrinsic programs, while regression of basal dendrites requires cue(s) from the extracellular environment in the dentate gyrus. The apical dendrite designation is determined from among multiple growing dendrites of young developing neurons.

  19. 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.

  20. Dendritic Cells Endocytose Bacillus Anthracis Spores: Implications for Anthrax Pathogenesis

    Science.gov (United States)

    2007-11-02

    Dendritic Cells Endocytose Bacillus anthracis Spores: Implications for Anthrax Pathogenesis1 Katherine C. Brittingham,* Gordon Ruthel,* Rekha G...germination and dissemination of spores. Found in high frequency throughout the respiratory track, dendritic cells (DCs) routinely take up foreign...COVERED - 4. TITLE AND SUBTITLE Dendritic cells endocytose Bacillus anthracis spores: implications for anthrax pathogenesis, The Journal of

  1. “Dermal dendritic cells” comprise two distinct populations: CD1+ dendritic cells and CD209+ macrophages

    OpenAIRE

    Ochoa,Maria Teresa; Loncaric, Anya; Krutzik, Stephan R.; Becker, Todd C.; Modlin, Robert L.

    2008-01-01

    A key cell type of the resident skin immune system is the dendritic cell, which in normal skin is located in two distinct microanatomical compartments: Langerhans cells (LC) mainly in the epidermis and dermal dendritic cells (DDC) in the dermis. Here, the lineage of dermal dendritic cells was investigated using monoclonal antibodies and immunohistology. We provide evidence that “dermal dendritic cells” comprise at least two major phenotypic populations of dendritic appearing cells: immature D...

  2. Characterization of chicken dendritic cell markers

    Science.gov (United States)

    Animal and Natural Resources Institute, ARS-USDA, Beltsville, MD, USA. New mouse monoclonal antibodies which detect CD80 and CD83 were developed to characterize chicken dendritic cells (DCs). The characteristics of these molecules have been studied in human, swine, ovine, feline, and canine but not ...

  3. Divergent Effects of Dendritic Cells on Pancreatitis

    Science.gov (United States)

    2015-09-01

    cells, Gr1+ inflammatory monocytes and neutrophils, or TNF production were induced to develop chronic pancreatitis in the context of DC overexpansion...Z. Yao, W. Cao, and Y.J. Liu. 2005. TSLP-activated dendritic cells induce an inflammatory T helper type 2 cell response through OX40 ligand. J. Exp...Public reporting burden for this collection of information is estimated to average 1 hour per response , including the time for reviewing instructions

  4. Distinct phenotype, longitudinal changes of numbers and cell-associated virus in blood dendritic cells in SIV-infected CD8-lymphocyte depleted macaques.

    Science.gov (United States)

    Soulas, Caroline; Autissier, Patrick J; Burdo, Tricia H; Piatak, Michael; Lifson, Jeffrey D; Williams, Kenneth C

    2015-01-01

    Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs) during HIV infection is well established. However, changes of myeloid DCs (mDCs) are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs.

  5. Distinct phenotype, longitudinal changes of numbers and cell-associated virus in blood dendritic cells in SIV-infected CD8-lymphocyte depleted macaques.

    Directory of Open Access Journals (Sweden)

    Caroline Soulas

    Full Text Available Loss of circulating CD123+ plasmacytoid dendritic cells (pDCs during HIV infection is well established. However, changes of myeloid DCs (mDCs are ambiguous since they are studied as a homogeneous CD11c+ population despite phenotypic and functional heterogeneity. Heterogeneity of CD11c+ mDCs in primates is poorly described in HIV and SIV infection. Using multiparametric flow cytometry, we monitored longitudinally cell number and cell-associated virus of CD123+ pDCs and non-overlapping subsets of CD1c+ and CD16+ mDCs in SIV-infected CD8-depleted rhesus macaques. The numbers of all three DC subsets were significantly decreased by 8 days post-infection. Whereas CD123+ pDCs were persistently depleted, numbers of CD1c+ and CD16+ mDCs rebounded. Numbers of CD1c+ mDCs significantly increased by 3 weeks post-infection while numbers of CD16+ mDCs remained closer to pre-infection levels. We found similar changes in the numbers of all three DC subsets in CD8 depleted animals as we found in animals that were SIV infected animals that were not CD8 lymphocyte depleted. CD16+ mDCs and CD123+ pDCs but not CD1c+ mDCs were significantly decreased terminally with AIDS. All DC subsets harbored SIV RNA as early as 8 days and then throughout infection. However, SIV DNA was only detected in CD123+ pDCs and only at 40 days post-infection consistent with SIV RNA, at least in mDCs, being surface-bound. Altogether our data demonstrate that SIV infection differently affects CD1c+ and CD16+ mDCs where CD16+ but not CD1c+ mDCs are depleted and might be differentially regulated in terminal AIDS. Finally, our data underline the importance of studying CD1c+ and CD16+ mDCs as discrete populations, and not as total CD11c+ mDCs.

  6. Differences between Human and Rodent Plasmacytoid Dendritic Cells May Explain the Pathogenic Disparity of Hantavirus Infection

    Science.gov (United States)

    2016-06-01

    Conclusion Several forms of skin cancer are successfully treated with the topical drug Imiquimod, which activates pDCs through toll-like receptor 7 engagement...neoplastic cells and in some cases, a complete regression [31,55–58]. Antineoplastic functions of pDCs DCs have the potential to invoke antitumour...typically associated with a positive diagnostic outcome [67,68]. The use of immunomodulating drugs to increase CTL responses has been shown to be an

  7. CTLA-4 blockade during dendritic cell based booster vaccination influences dendritic cell survival and CTL expansion

    DEFF Research Database (Denmark)

    Pedersen, Anders E; Ronchese, Franca

    2007-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells and critical for the priming of CD8+ T cells. Therefore the use of these cells as adjuvant cells has been tested in a large number of experimental and clinical vaccination studies, in particular cancer vaccine studies. A number of protocols...

  8. 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.

  9. Sensitivity of Dendritic Cells to Microenvironment Signals

    Science.gov (United States)

    Motta, Juliana Maria; Rumjanek, Vivian Mary

    2016-01-01

    Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies. PMID:27088097

  10. Sensitivity of Dendritic Cells to Microenvironment Signals

    Directory of Open Access Journals (Sweden)

    Juliana Maria Motta

    2016-01-01

    Full Text Available Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.

  11. Dendritic Cells for SYN Scan Detection

    CERN Document Server

    Greensmith, Julie

    2010-01-01

    Artificial immune systems have previously been applied to the problem of intrusion detection. The aim of this research is to develop an intrusion detection system based on the function of Dendritic Cells (DCs). DCs are antigen presenting cells and key to activation of the human immune system, behaviour which has been abstracted to form the Dendritic Cell Algorithm (DCA). In algorithmic terms, individual DCs perform multi-sensor data fusion, asynchronously correlating the the fused data signals with a secondary data stream. Aggregate output of a population of cells, is analysed and forms the basis of an anomaly detection system. In this paper the DCA is applied to the detection of outgoing port scans using TCP SYN packets. Results show that detection can be achieved with the DCA, yet some false positives can be encountered when simultaneously scanning and using other network services. Suggestions are made for using adaptive signals to alleviate this uncovered problem.

  12. The CFH Optical PDCS Survey (COP) First results

    CERN Document Server

    Adami, C; Mazure, A; Castander, F J; Nichol, R; Ulmer, M P; Postman, M; Lubin, L M

    1999-01-01

    We present the first results of the COP survey about the reality of the PDCS clusters, about their velocity dispersions and dynamic and about the periodicity of the structures along the line of sight.

  13. Crosstalk between dendritic cell subsets and implications for dendritic cell-based anticancer immunotherapy

    NARCIS (Netherlands)

    Bakdash, G.; Schreurs, I.; Schreibelt, G.; Tel, J.

    2014-01-01

    Dendritic cells (DCs) are a family of professional antigen-presenting cells that have an indispensable role in the initiation of innate and adaptive immune responses against pathogens and tumor cells. The DC family is very heterogeneous. Two main types of naturally occurring DCs circulate in periphe

  14. Dendritic Cells as Danger-Recognizing Biosensors

    Directory of Open Access Journals (Sweden)

    Seokmann Hong

    2009-08-01

    Full Text Available Dendritic cells (DCs are antigen presenting cells that are characterized by a potent capacity to initiate immune responses. DCs comprise several subsets with distinct phenotypes. After sensing any danger(s to the host via their innate immune receptors such as Toll-like receptors, DCs become mature and subsequently present antigens to CD4+ T cells. Since DCs possess the intrinsic capacity to polarize CD4+ helper cells, it is critical to understand the immunological roles of DCs for clinical applications. Here, we review the different DC subsets, their danger-sensing receptors and immunological functions. Furthermore, the cytokine reporter mouse model for studying DC activation is introduced.

  15. Improvement of human dendritic cell culture for immunotoxicological investigations.

    Science.gov (United States)

    Hymery, N; Sibiril, Y; Parent-Massin, D

    2006-07-01

    A toxic injury such as a decrease in the number of immature dendritic cells caused by a cytotoxic effect or a disturbance in their maturation process can be responsible for immunodepression. There is a need to improve in vitro assays on human dendritic cells used to detect and evaluate adverse effects of xenobiotics. Two aspects were explored in this work: cytotoxic effects of xenobiotics on immature dendritic cells, and the interference of xenobiotics with dendritic cell maturation. Dendritic cells of two different origins were tested. Dendritic cells obtained either from umbilical cord blood CD34(+) cells or, for the first time, from umbilical cord blood monocytes. The cytotoxicity assay on immature dendritic cells has been improved. For the study of the potential adverse effects of xenobiotics on the maturation process of dendritic cells, several parameters were selected such as expression of markers (CD86, CD83, HLA-DR), secretion of interleukins 10 and 12, and proliferation of autologous lymphocytes. The relevance and the efficiency of the protocol applied were tested using two mycotoxins, T-2 toxin and deoxynivalence, DON, which are known to be immunosuppressive, and one phycotoxin, domoic acid, which is known not to have any immunotoxic effect. Assays using umbilical cord monocyte dendritic cell cultures with the protocol defined in this work, which involves a cytotoxicity study followed by evaluation of several markers of adverse effects on the dendritic cell maturation process, revealed their usefulness for investigating xenobiotic immunotoxicity toward immune primary reactions.

  16. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1997-01-01

    Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

  17. Semiautomated analysis of dendrite morphology in cell culture.

    Science.gov (United States)

    Sweet, Eric S; Langhammer, Chris L; Kutzing, Melinda K; Firestein, Bonnie L

    2013-01-01

    Quantifying dendrite morphology is a method for determining the effect of biochemical pathways and extracellular agents on neuronal development and differentiation. Quantification can be performed using Sholl analysis, dendrite counting, and length quantification. These procedures can be performed on dendrite-forming cell lines or primary neurons grown in culture. In this protocol, we describe the use of a set of computer programs to assist in quantifying many aspects of dendrite morphology, including changes in total and localized arbor complexity.

  18. Remodeling of monoplanar Purkinje cell dendrites during cerebellar circuit formation.

    Directory of Open Access Journals (Sweden)

    Megumi Kaneko

    Full Text Available Dendrite arborization patterns are critical determinants of neuronal connectivity and integration. Planar and highly branched dendrites of the cerebellar Purkinje cell receive specific topographical projections from two major afferent pathways; a single climbing fiber axon from the inferior olive that extend along Purkinje dendrites, and parallel fiber axons of granule cells that contact vertically to the plane of dendrites. It has been believed that murine Purkinje cell dendrites extend in a single parasagittal plane in the molecular layer after the cell polarity is determined during the early postnatal development. By three-dimensional confocal analysis of growing Purkinje cells, we observed that mouse Purkinje cells underwent dynamic dendritic remodeling during circuit maturation in the third postnatal week. After dendrites were polarized and flattened in the early second postnatal week, dendritic arbors gradually expanded in multiple sagittal planes in the molecular layer by intensive growth and branching by the third postnatal week. Dendrites then became confined to a single plane in the fourth postnatal week. Multiplanar Purkinje cells in the third week were often associated by ectopic climbing fibers innervating nearby Purkinje cells in distinct sagittal planes. The mature monoplanar arborization was disrupted in mutant mice with abnormal Purkinje cell connectivity and motor discoordination. The dendrite remodeling was also impaired by pharmacological disruption of normal afferent activity during the second or third postnatal week. Our results suggest that the monoplanar arborization of Purkinje cells is coupled with functional development of the cerebellar circuitry.

  19. Dendritic cells modified by vitamin D

    DEFF Research Database (Denmark)

    Pedersen, Ayako Wakatsuki; Claesson, Mogens Helweg; Zocca, Mai-Britt

    2011-01-01

    Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell ...... and the optimal frequency, dose, and route of DC administration to achieve therapeutic effects in humans, adoptive VD3-DC transfer represents one of the most promising approaches to future treatment of autoimmune diseases.......Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell...... costimulatory molecules and hampered IL-12 production. These VD3-modulated DCs induce T cell tolerance in vitro using multiple mechanisms such as rendering T cells anergic, dampening of Th1 responses, and recruiting and differentiating regulatory T cells. Due to their ability to specifically target pathological...

  20. Inducible expression of endomorphins in murine dendritic cells.

    Science.gov (United States)

    Yang, Xiaohuai; Xia, Hui; Chen, Yong; Liu, Xiaofen; Zhou, Cheng; Gao, Qin; Li, Zhenghong

    2012-12-15

    Bone marrow precursor cells were extracted from C57BL/6J mice aged 7-8 weeks, and dendritic cells were purified using anti-CD11c (a specific marker for dendritic cells) antibody-coated magnetic beads. Immunofluorescence staining revealed that the expression levels of endomorphin-1 and endomorphin-2 were upregulated in dendritic cells activated by lipopolysaccharide. An enzyme immunoassay showed that lipopolysaccharide and other Toll-like receptor ligands promoted the secretion of endomorphin-1 and endomorphin-2 from activated dendritic cells. [(3)H]-thymidine incorporation demonstrated that endomorphin-1 and endomorphin-2 both inhibited the proliferation of T lymphocyte induced by activated dendritic cells. Furthermore, this immunosuppressive effect was blocked by CTOP, a specific antagonist of µ-opioid receptors. Our experimental findings indicate that activated dendritic cells can induce the expression and secretion of endomorphins, and that endomorphins suppress T lymphocyte proliferation through activation of µ-opioid receptors.

  1. Inducible expression of endomorphins in murine dendritic cells

    Institute of Scientific and Technical Information of China (English)

    Xiaohuai Yang; Hui Xia; Yong Chen; Xiaofen Liu; Cheng Zhou; Qin Gao; Zhenghong Li

    2012-01-01

    Bone marrow precursor cells were extracted from C57BL/6J mice aged 7–8 weeks, and dendritic cells were purified using anti-CD11c (a specific marker for dendritic cells) antibody-coated magnetic beads. Immunofluorescence staining revealed that the expression levels of endomorphin-1 and endomorphin-2 were upregulated in dendritic cells activated by lipopolysaccharide. An enzyme immunoassay showed that lipopolysaccharide and other Toll-like receptor ligands promoted the secretion of endomorphin-1 and endomorphin-2 from activated dendritic cells. [3H]-thymidine incorporation demonstrated that endomorphin-1 and endomorphin-2 both inhibited the proliferation of T lymphocyte induced by activated dendritic cells. Furthermore, this immunosuppressive effect was blocked by CTOP, a specific antagonist of μ-opioid receptors. Our experimental findings indicate that activated dendritic cells can induce the expression and secretion of endomorphins, and that endomorphins suppress T lymphocyte proliferation through activation of μ-opioid receptors.

  2. Reduction of conventional dendritic cells during Plasmodium infection is dependent on activation induced cell death by type I and II interferons.

    Science.gov (United States)

    Tamura, Takahiko; Kimura, Kazumi; Yui, Katsuyuki; Yoshida, Shigeto

    2015-12-01

    Dendritic cells (DCs) play critical roles in innate and adaptive immunity and in pathogenesis during the blood stage of malaria infection. The mechanisms underlying DC homeostasis during malaria infection are not well understood. In this study, the numbers of conventional DCs (cDCs) and plasmacytoid DCs (pDCs) in the spleens after lethal rodent malaria infection were examined, and were found to be significantly reduced. Concomitant with up-regulation of maturation-associated molecules, activation of caspase-3 was significantly increased, suggesting induction of cell death. Studies using neutralizing antibody and gene-deficient mice showed that type I and II interferons were critically involved in activation induced cell death of cDCs during malaria infection. These results demonstrate that DCs rapidly disappeared following IFN-mediated DC activation, and that homeostasis of DCs was significantly impaired during malaria infection.

  3. Decrease in Circulating Dendritic Cell Precursors in Patients with Peripheral Artery Disease

    Directory of Open Access Journals (Sweden)

    Daniel Kretzschmar

    2015-01-01

    Full Text Available Peripheral artery disease (PAD is a common manifestation of atherosclerosis. Inflammation is important for initiation and progression of the disease. Dendritic cells (DCs as antigen-presenting cells play an important role in the immune system. Therefore, we hypothesize that, in patients with PAD, DCPs might be reduced in blood due to their recruitment into the vascular wall and induce a proinflammatory response. The numbers of myeloid DCPs, plasmacytoid DCPs, and total DCPs were analyzed by flow cytometry in blood of patients with PAD (n=52 compared to controls (n=60. Femoralis plaques (n=12 of patients who underwent surgery were immunostained for CD209 and CD83 (mDCs as well as CD304, CD123 (pDCs, and HLA-DR. In patients with PAD, a significant decrease in mDCPs, pDCPs, and tDCPs was observed. In immunostaining, markers indicative for mDCs (CD209: 16 versus 8 cells/0.1 mm2, P=0.02; CD83: 19 versus 5 cells/0.1 mm2, P=0.03 were significantly elevated in femoralis plaques compared to control vessels. We show for the first time that mDCPs, pDCPs, and tDCPs are significantly reduced in patients with PAD. Immunohistochemical analysis unraveled that the decrease in DCPs might be due to their recruitment into atherosclerotic plaques.

  4. Dendritic Cells in vivo and in vitro

    Institute of Scientific and Technical Information of China (English)

    Hui Wan; Marcel Dupasquier

    2005-01-01

    Dendritic cells (DC) are crucial cells of the immune system, and bridged the essential connection between innate and adaptive immunity. They reside in the periphery as sentinels where they take up antigens. Upon activation,they migrate to lymphoid organs and present there the processed antigens to T cells, thereby activating them and eliciting a potent immune response. Dendritic cells are bone marrow-derived cells, still big controversies exist about their in vivo development. In vitro, DC can be generated from multiple precursor cells, among them lymphoid and myeloid committed progenitors. Although it remains unknown how DC are generated in vivo,studying the functions of in vitro generated DC results in fundamental knowledge of the DC biology with promising applications for future medicine. Therefore, in this review, we present current protocols for the generation of DC from precursors in vitro. We will do this for the mouse system, where most research occurs and for the human system, where research concentrates on implementing DC biology in disease treatments.

  5. Dendritic Cells in vivo and in vitro

    Institute of Scientific and Technical Information of China (English)

    HuiWan; MarcelDupasquier

    2005-01-01

    Dendritic cells (DC) are crucial cells of the immune system, and bridged the essential connection between innate and adaptive immunity. They reside in the periphery as sentinels where they take up antigens. Upon activation, they migrate to lymphoid organs and present there the processed antigens to T cells, thereby activating them and eliciting a potent immune response. Dendritic cells are bone marrow-derived cells, still big controversies exist about their in vivo development. In vitro, DC can be generated from multiple precursor cells, among them lymphoid and myeloid committed progenitors. Although it remains unknown how DC are generated in vivo, studying the functions of in vitro generated DC results in fundamental knowledge of the DC biology with promising applications for future medicine. Therefore, in this review, we present current protocols for the generation of DC from precursors in vitro. We will do this for the mouse system, where most research occurs and for the human system, where research concentrates on implementing DC biology in disease treatments. Cellular & Molecular Immunology. 2005;2(1):28-35.

  6. In vitro effects of trichothecenes on human dendritic cells.

    Science.gov (United States)

    Hymery, N; Sibiril, Y; Parent-Massin, D

    2006-09-01

    The aim of this work was to study the in vitro effects of trichothecenes on human dendritic cells. Trichothecenes are mycotoxins produced by fungi such as Fusarium, Myrothecium, and Stachybotrys. Two aspects have been explored in this work: the cytotoxicity of trichothecenes on immature dendritic cells to determine IC 50 (inhibition concentration), and the effects of trichothecenes on dendritic cell maturation process. Two mycotoxins (T-2 and DON) known to be immunotoxic have been tested on a model of monocyte-derived dendritic cells culture. Cytotoxic effects of T-2 toxin and DON on immature dendritic cells showed that DON is less potent than T-2 toxin. The exposure to trichothecenes during dendritic cell maturation upon addition of LPS or TNF-alpha markedly inhibited the up-regulation of maturation markers such as CD-86, HLA-DR and CCR7. Features of LPS or TNF-alpha -mediated maturation of dendritic cells, such as IL-10 and IL-12 secretions and endocytosis, were also impaired in response to trichothecenes treatment. These results suggest trichothecenes have adverse effects on dendritic cells and dendritic cell maturation process.

  7. Immune Monitoring Using mRNA-Transfected Dendritic Cells

    DEFF Research Database (Denmark)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by m......RNA electroporation, ensuring presentation of antigen through major histocompatibility complex I and potentially activating T cells, enabling them to kill the tumor cells. Despite extensive research in the field, only one dendritic cell-based vaccine has been approved. There is therefore a great need to elucidate...... and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA....

  8. Targeting vaccines to dendritic cells

    DEFF Research Database (Denmark)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-01-01

    to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC...... are considered to play a central role for the provocation of primary immune responses by vaccination. A rational way of improving the potency and safety of new and already existing vaccines could therefore be to direct vaccines specifically to DC. There is a need for developing multifunctional vaccine drug...... delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC....

  9. Fast generation of dendritic cells

    DEFF Research Database (Denmark)

    Kvistborg, P; Bøgh, Marie; Claesson, M H

    2009-01-01

    we have developed fast DC protocol by comparing two different fast DC protocols with SDDC. DC were evaluated by FACS analysis, and the optimal profile was considered: CD14(low), CD80(high), CD83(high), CD86(high), CCR7(high), HLA class I and II(high). FACS profiles were used as the selection criteria...... together with yield and morphology. Two fast DC protocols fulfilled these criteria and were selected for functional analysis. Our results demonstrate that DC generated within 5days or 48h are comparable with SDDC both phenotypically and functionally. However, we found that 48h DC were more susceptible than...... SDDC to the IL-10 inducing stimulus of TLR ligands (R848 and LPS). Thus to determine the clinical relevance of fast DC protocols in cancer settings, small phase I trials should be conducted monitoring regulatory T cells carefully....

  10. Dendritic planarity of Purkinje cells is independent of Reelin signaling.

    Science.gov (United States)

    Kim, Jinkyung; Park, Tae-Ju; Kwon, Namseop; Lee, Dongmyeong; Kim, Seunghwan; Kohmura, Yoshiki; Ishikawa, Tetsuya; Kim, Kyong-Tai; Curran, Tom; Je, Jung Ho

    2015-07-01

    The dendritic planarity of Purkinje cells is critical for cerebellar circuit formation. In the absence of Crk and CrkL, the Reelin pathway does not function resulting in partial Purkinje cell migration and defective dendritogenesis. However, the relationships among Purkinje cell migration, dendritic development and Reelin signaling have not been clearly delineated. Here, we use synchrotron X-ray microscopy to obtain 3-D images of Golgi-stained Purkinje cell dendrites. Purkinje cells that failed to migrate completely exhibited conical dendrites with abnormal 3-D arborization and reduced dendritic complexity. Furthermore, their spines were fewer in number with a distorted morphology. In contrast, Purkinje cells that migrated successfully displayed planar dendritic and spine morphologies similar to normal cells, despite reduced dendritic complexity. These results indicate that, during cerebellar formation, Purkinje cells migrate into an environment that supports development of dendritic planarity and spine formation. While Reelin signaling is important for the migration process, it does not make a direct major contribution to dendrite formation.

  11. Harnessing Dendritic Cells for Tumor Antigen Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Nierkens, Stefan [Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, Nijmegen 6525 GA (Netherlands); Janssen, Edith M., E-mail: edith.janssen@cchmc.org [Division of Molecular Immunology, Cincinnati Children' s Hospital Research Foundation, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States)

    2011-04-26

    Dendritic cells (DC) are professional antigen presenting cells that are crucial for the induction of anti-tumor T cell responses. As a consequence, research has focused on the harnessing of DCs for therapeutic interventions. Although current strategies employing ex vivo-generated and tumor-antigen loaded DCs have been proven feasible, there are still many obstacles to overcome in order to improve clinical trial successes and offset the cost and complexity of customized cell therapy. This review focuses on one of these obstacles and a pivotal step for the priming of tumor-specific CD8{sup +} and CD4{sup +} T cells; the in vitro loading of DCs with tumor antigens.

  12. Homophilic Protocadherin Cell-Cell Interactions Promote Dendrite Complexity

    Directory of Open Access Journals (Sweden)

    Michael J. Molumby

    2016-05-01

    Full Text Available Growth of a properly complex dendrite arbor is a key step in neuronal differentiation and a prerequisite for neural circuit formation. Diverse cell surface molecules, such as the clustered protocadherins (Pcdhs, have long been proposed to regulate circuit formation through specific cell-cell interactions. Here, using transgenic and conditional knockout mice to manipulate γ-Pcdh repertoire in the cerebral cortex, we show that the complexity of a neuron’s dendritic arbor is determined by homophilic interactions with other cells. Neurons expressing only one of the 22 γ-Pcdhs can exhibit either exuberant or minimal dendrite complexity, depending only on whether surrounding cells express the same isoform. Furthermore, loss of astrocytic γ-Pcdhs, or disruption of astrocyte-neuron homophilic matching, reduces dendrite complexity cell non-autonomously. Our data indicate that γ-Pcdhs act locally to promote dendrite arborization via homophilic matching, and they confirm that connectivity in vivo depends on molecular interactions between neurons and between neurons and astrocytes.

  13. Differentiation of apical and basal dendrites in pyramidal cells and granule cells in dissociated hippocampal cultures.

    Directory of Open Access Journals (Sweden)

    You Kure Wu

    Full Text Available Hippocampal pyramidal cells and dentate granule cells develop morphologically distinct dendritic arbors, yet also share some common features. Both cell types form a long apical dendrite which extends from the apex of the cell soma, while short basal dendrites are developed only in pyramidal cells. Using quantitative morphometric analyses of mouse hippocampal cultures, we evaluated the differences in dendritic arborization patterns between pyramidal and granule cells. Furthermore, we observed and described the final apical dendrite determination during dendritic polarization by time-lapse imaging. Pyramidal and granule cells in culture exhibited similar dendritic patterns with a single principal dendrite and several minor dendrites so that the cell types were not readily distinguished by appearance. While basal dendrites in granule cells are normally degraded by adulthood in vivo, cultured granule cells retained their minor dendrites. Asymmetric growth of a single principal dendrite harboring the Golgi was observed in both cell types soon after the onset of dendritic growth. Time-lapse imaging revealed that up until the second week in culture, final principal dendrite designation was not stabilized, but was frequently replaced by other minor dendrites. Before dendritic polarity was stabilized, the Golgi moved dynamically within the soma and was repeatedly repositioned at newly emerging principal dendrites. Our results suggest that polarized growth of the apical dendrite is regulated by cell intrinsic programs, while regression of basal dendrites requires cue(s from the extracellular environment in the dentate gyrus. The apical dendrite designation is determined from among multiple growing dendrites of young developing neurons.

  14. Viruses, dendritic cells and the lung

    Directory of Open Access Journals (Sweden)

    Graham Barney S

    2001-06-01

    Full Text Available Abstract The interaction between viruses and dendritic cells (DCs is varied and complex. DCs are key elements in the development of a host response to pathogens such as viruses, but viruses have developed survival tactics to either evade or diminish the immune system that functions to kill and eliminate these micro-organisms. In the present review we summarize current concepts regarding the function of DCs in the immune system, our understanding of how viruses alter DC function to attenuate both the virus-specific and global immune response, and how we may be able to exploit DC function to prevent or treat viral infections.

  15. Metamaterial absorber with random dendritic cells

    Science.gov (United States)

    Zhu, Weiren; Zhao, Xiaopeng

    2010-05-01

    The metamaterial absorber composed of random dendritic cells has been investigated at microwave frequencies. It is found that the absorptivities come to be weaker and the resonant frequency get red shift as the disordered states increasing, however, the random metamaterial absorber still presents high absorptivity more than 95%. The disordered structures can help understanding of the metamaterial absorber and may be employed for practical design of infrared metamaterial absorber, which may play important roles in collection of radiative heat energy and directional transfer enhancement.

  16. Estrogen Receptor-Dependent Regulation of Dendritic Cell Development and Function

    Science.gov (United States)

    Laffont, Sophie; Seillet, Cyril; Guéry, Jean-Charles

    2017-01-01

    Autoimmunity, infectious diseases and cancer affect women and men differently. Because they tend to develop more vigorous adaptive immune responses than men, women are less susceptible to some infectious diseases but also at higher risk of autoimmunity. The regulation of immune responses by sex-dependent factors probably involves several non-redundant mechanisms. A privileged area of study, however, concerns the role of sex steroid hormones in the biology of innate immune cells, especially dendritic cells (DCs). In recent years, our understanding of the lineage origin of DC populations has expanded, and the lineage-committing transcription factors shaping peripheral DC subsets have been identified. Both progenitor cells and mature DC subsets express estrogen receptors (ERs), which are ligand-dependent transcription factors. This suggests that estrogens may contribute to the reported sex differences in immunity by regulating DC biology. Here, we review the recent literature and highlight evidence that estrogen-dependent activation of ERα regulates the development or the functional responses of particular DC subsets. The in vitro model of GM-CSF-induced DC differentiation shows that CD11c+ CD11bint Ly6cneg cells depend on ERα activation by estrogen for their development, and for the acquisition of competence to activate naive CD4+ T lymphocytes and mount a robust pro-inflammatory cytokine response to CD40 stimulation. In this model, estrogen signaling in conjunction with GM-CSF is necessary to promote early interferon regulatory factor (Irf)-4 expression in macrophage-DC progenitors and their subsequent differentiation into IRF-4hi CD11c+ CD11bint Ly6cneg cells, closely related to the cDC2 subset. The Flt3L-induced model of DC differentiation in turn shows that ERα signaling promotes the development of conventional DC (cDC) and plasmacytoid DC (pDC) with higher capability of pro-inflammatory cytokine production in response to TLR stimulation. Likewise, cell

  17. In vivo evidence for dendritic cell lysis by NK cells

    OpenAIRE

    Ferlazzo, Guido

    2012-01-01

    By using an experimental model of anticancer vaccination, we have recently lent support to the assumption, so far only sustained by in vitro data, that natural killer cells can restrain less immunogenic, allegedly tolerogenic, dendritic cells (DCs). This in vivo selection of immunogenic DCs appears to depend on perforin and to be associated with a more protective tumor-specific T lymphocyte response.

  18. Dendritic cell-tumor cell hybrids and immunotherapy

    DEFF Research Database (Denmark)

    Cathelin, Dominique; Nicolas, Alexandra; Bouchot, André

    2011-01-01

    Dendritic cells (DC) are professional antigen-presenting cells currently being used as a cellular adjuvant in cancer immunotherapy strategies. Unfortunately, DC-based vaccines have not demonstrated spectacular clinical results. DC loading with tumor antigens and DC differentiation and activation...

  19. Information Fusion for Anomaly Detection with the Dendritic Cell Algorithm

    CERN Document Server

    Greensmith, Julie; Tedesco, Gianni

    2010-01-01

    Dendritic cells are antigen presenting cells that provide a vital link between the innate and adaptive immune system, providing the initial detection of pathogenic invaders. Research into this family of cells has revealed that they perform information fusion which directs immune responses. We have derived a Dendritic Cell Algorithm based on the functionality of these cells, by modelling the biological signals and differentiation pathways to build a control mechanism for an artificial immune system. We present algorithmic details in addition to experimental results, when the algorithm was applied to anomaly detection for the detection of port scans. The results show the Dendritic Cell Algorithm is sucessful at detecting port scans.

  20. 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.

  1. Triggering of dendritic cell apoptosis by xanthohumol.

    Science.gov (United States)

    Xuan, Nguyen Thi; Shumilina, Ekaterina; Gulbins, Erich; Gu, Shuchen; Götz, Friedrich; Lang, Florian

    2010-07-01

    Xanthohumol, a flavonoid from beer with anticancer activity is known to trigger apoptosis in a variety of tumor cells. Xanthohumol further has anti-inflammatory activity. However, little is known about the effect of xanthohumol on survival and function of immune cells. The present study thus addressed the effect of xanthohumol on dendritic cells (DCs), key players in the regulation of innate and adaptive immunity. To this end, mouse bone marrow-derived DCs were treated with xanthohumol with subsequent assessment of enzymatic activity of acid sphingomyelinase (Asm), ceramide formation determined with anti-ceramide antibodies in FACS and immunohistochemical analysis, caspase activity utilizing FITC conjugated anti-active caspase 8 or caspase 3 antibodies in FACS and by Western blotting, DNA fragmentation by determining the percentage of cells in the sub-G1 phase and cell membrane scrambling by annexin V binding in FACS analysis. As a result, xanthohumol stimulated Asm, enhanced ceramide formation, activated caspases 8 and 3, triggered DNA fragmentation and led to cell membrane scrambling, all effects virtually absent in DCs from gene targeted mice lacking functional Asm or in wild-type cells treated with sphingomyelinase inhibitor amitriptyline. In conclusion, xanthohumol stimulated Asm leading to caspase activation and apoptosis of bone marrow-derived DCs.

  2. Low Counts of Plasmacytoid Dendritic Cells after Engraftment Are Associated with High Early Mortality after Allogeneic Stem Cell Transplantation.

    Science.gov (United States)

    Gonçalves, Matheus Vescovi; Yamamoto, Mihoko; Kimura, Eliza Yurico Sugano; Colturato, Vergílio Antônio Rensi; de Souza, Mair Pedro; Mauad, Marcos; Ikoma, Maura Valerio; Novis, Yana; Rocha, Vanderson; Ginani, Valeria Cortez; Wanderley de Oliveira Felix, Olga Margareth; Seber, Adriana; Kerbauy, Fabio Rodrigues; Hamerschlak, Nelson; Orfao, Alberto; Rodrigues, Celso Arrais

    2015-07-01

    Dendritic cells (DCs) are antigen-presenting cells that drive immune responses and tolerance and are divided in different subsets: myeloid DCs (mDCs: lineage-; HLA-DR+, 11c+), plasmacytoid dendritic cells (pDCs: HLA-DR+, CD123+), and monocyte-derived DCs (moDC: lineage-, 11c+, 16+). After hematopoietic stem cell transplantation (HSCT), low DC counts in the recipients' peripheral blood (PB) have been associated with worse outcomes, but the relevance of DC graft content remains unclear, and there are few data in the setting of unrelated donor HSCT. We evaluated the DC graft content and monitored DC recovery in PB from 111 HSCT recipients (median age, 17 years; range 1 to 74), who received bone marrow (46%), umbilical cord blood (32%), or PB (22%) from unrelated (81%) or related donors (19%). In 86 patients with sustained allogeneic recovery, patients with higher counts of all DC subsets (pDC, mDC, and moDC) 3 weeks after engraftment had lower incidence of nonrelapse mortality (NMR) and acute graft-versus-host disease (aGVHD) and better survival. pDC counts were associated with more striking results: patients with higher pDC counts had much lower incidences of NRM (3% versus 47%, P < .0001), lower incidence of aGVHD (24% versus 67%, P < .0001), and better overall survival (92% versus 45%, P < .0001). In contrast, higher pDC counts in the graft was associated with an increased risk of aGVHD (55% versus 26%, P = .02). Our results indicate that DC counts are closely correlated with HSCT outcomes and warrant further prospective evaluation and possible early therapeutic interventions to ameliorate severe aGVHD and decrease mortality.

  3. 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.

  4. Harnessing dendritic cells in inflammatory skin diseases.

    Science.gov (United States)

    Chu, Chung-Ching; Di Meglio, Paola; Nestle, Frank O

    2011-02-01

    The skin immune system harbors a complex network of dendritic cells (DCs). Recent studies highlight a diverse functional specialization of skin DC subsets. In addition to generating cellular and humoral immunity against pathogens, skin DCs are involved in tolerogenic mechanisms to ensure the maintenance of immune homeostasis, as well as in pathogenesis of chronic inflammation in the skin when excessive immune responses are initiated and unrestrained. Harnessing DCs by directly targeting DC-derived molecules or selectively modulate DC subsets is a convincing strategy to tackle inflammatory skin diseases. In this review we discuss recent advances underlining the functional specialization of skin DCs and discuss the potential implication for future DC-based therapeutic strategies.

  5. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1998-01-01

    The specific aims of the project were: (1) Application of the NASA bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC). (2) Compare the frequency and function of DC in normal donors and immunocompromised cancer patients. (3) Analyze the effectiveness of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in a murine model of experimental fungal disease. Our investigations have provided new insight into DC immunobiology and have led to the development of methodology to evaluate DC in blood of normal donors and patients. Information gained from these studies has broadened our understanding of possible mechanisms involved in the immune dysfunction of space travelers and earth-bound cancer patients, and could contribute to the design of novel therapies to restore/preserve immunity in these individuals. Several new avenues of investigation were also revealed. The results of studies completed during Round 2 are summarized.

  6. Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum

    OpenAIRE

    Ziegler, A; Everett, H.; Hamza, E; Garbani, M; Gerber, V.; Marti, E; Steinbach, F

    2016-01-01

    Background: Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including horses. ...

  7. Macrophages and Dendritic Cells: Partners in Atherogenesis.

    Science.gov (United States)

    Cybulsky, Myron I; Cheong, Cheolho; Robbins, Clinton S

    2016-02-19

    Atherosclerosis is a complex chronic disease. The accumulation of myeloid cells in the arterial intima, including macrophages and dendritic cells (DCs), is a feature of early stages of disease. For decades, it has been known that monocyte recruitment to the intima contributes to the burden of lesion macrophages. Yet, this paradigm may require reevaluation in light of recent advances in understanding of tissue macrophage ontogeny, their capacity for self-renewal, as well as observations that macrophages proliferate throughout atherogenesis and that self-renewal is critical for maintenance of macrophages in advanced lesions. The rate of atherosclerotic lesion formation is profoundly influenced by innate and adaptive immunity, which can be regulated locally within atherosclerotic lesions, as well as in secondary lymphoid organs, the bone marrow and the blood. DCs are important modulators of immunity. Advances in the past decade have cemented our understanding of DC subsets, functions, hematopoietic origin, gene expression patterns, transcription factors critical for differentiation, and provided new tools for study of DC biology. The functions of macrophages and DCs overlap to some extent, thus it is important to reassess the contributions of each of these myeloid cells taking into account strict criteria of cell identification, ontogeny, and determine whether their key roles are within atherosclerotic lesions or secondary lymphoid organs. This review will highlight key aspect of macrophage and DC biology, summarize how these cells participate in different stages of atherogenesis and comment on complexities, controversies, and gaps in knowledge in the field.

  8. Dendritic Cells in the Cancer Microenvironment

    Directory of Open Access Journals (Sweden)

    Yang Ma, Galina V. Shurin, Zhu Peiyuan, Michael R. Shurin

    2013-01-01

    Full Text Available The complexity of the tumor immunoenvironment is underscored by the emergence and discovery of different subsets of immune effectors and regulatory cells. Tumor-induced polarization of immune cell differentiation and function makes this unique environment even more intricate and variable. Dendritic cells (DCs represent a special group of cells that display different phenotype and activity at the tumor site and exhibit differential pro-tumorigenic and anti-tumorigenic functions. DCs play a key role in inducing and maintaining the antitumor immunity, but in the tumor environment their antigen-presenting function may be lost or inefficient. DCs might be also polarized into immunosuppressive/tolerogenic regulatory DCs, which limit activity of effector T cells and support tumor growth and progression. Although various factors and signaling pathways have been described to be responsible for abnormal functioning of DCs in cancer, there are still no feasible therapeutic modalities available for preventing or reversing DC malfunction in tumor-bearing hosts. Thus, better understanding of DC immunobiology in cancer is pivotal for designing novel or improved therapeutic approaches that will allow proper functioning of DCs in patients with cancer.

  9. Derivation and Utilization of Functional CD8(+) Dendritic Cell Lines.

    Science.gov (United States)

    Pigni, Matteo; Ashok, Devika; Acha-Orbea, Hans

    2016-01-01

    It is notoriously difficult to obtain large quantities of non-activated dendritic cells ex vivo. For this reason, we produced and characterized a mouse model expressing the large T oncogene under the CD11c promoter (Mushi mice), in which CD8α(+) dendritic cells transform after 4 months. We derived a variety of stable cell lines from these primary lines. These cell lines reproducibly share with freshly isolated dendritic cells most surface markers, mRNA and protein expression, and all tested biological functions. Cell lines can be derived from various strains and knockout mice and can be easily transduced with lentiviruses. In this article, we describe the derivation, culture, and lentiviral transduction of these dendritic cell lines.

  10. Iron acquisition by Mycobacterium tuberculosis residing within myeloid dendritic cells.

    Science.gov (United States)

    Olakanmi, Oyebode; Kesavalu, Banurekha; Abdalla, Maher Y; Britigan, Bradley E

    2013-12-01

    The pathophysiology of Mycobacterium tuberculosis (M.tb) infection is linked to the ability of the organism to grow within macrophages. Lung myeloid dendritic cells are a newly recognized reservoir of M.tb during infection. Iron (Fe) acquisition is critical for M.tb growth. In vivo, extracellular Fe is chelated to transferrin (TF) and lactoferrin (LF). We previously reported that M.tb replicating in human monocyte-dervied macrophages (MDM) can acquire Fe bound to TF, LF, and citrate, as well as from the MDM cytoplasm. Access of M.tb to Fe may influence its growth in macrophages and dendritic cells. In the present work we confirmed the ability of different strains of M.tb to grow in human myeloid dendritic cells in vitro. Fe acquired by M.tb replicating within dendritic cells from externally added Fe chelates varied with the Fe chelate present in the external media: Fe-citrate > Fe-LF > Fe-TF. Fe acquisition rates from each chelate did not vary over 7 days. M.tb within dendritic cells also acquired Fe from the dendritic cell cytoplasm, with the efficiency of Fe acquisition greater from cytoplasmic Fe sources, regardless of the initial Fe chelate from which that cytoplasmic Fe was derived. Growth and Fe acquisition results with human MDM were similar to those with dendritic cells. M.tb grow and replicate within myeloid dendritic cells in vitro. Fe metabolism of M.tb growing in either MDM or dendritic cells in vitro is influenced by the nature of Fe available and the organism appears to preferentially access cytoplasmic rather than extracellular Fe sources. Whether these in vitro data extend to in vivo conditions should be examined in future studies.

  11. A short-term increase of the postoperative naturally circulating dendritic cells subsets in flurbiprofen-treated patients with esophageal carcinoma undergoing thoracic surgery

    Science.gov (United States)

    Chai, Xiao-qing; Shu, Shu-hua; Zhang, Xiao-lin; Xie, Yan-hu; Wei, Xin; Wu, Yu-jing; Wei, Wei

    2016-01-01

    The present study evaluated whether flurbiprofen increased the naturally circulating dendritic cells (DCs) subsets in patients with esophageal squamous cell carcinoma (ESCC) undergoing esophageal resection. Compared to healthy donors (n=20), the significantly depressed percentages of plasmacytoid DCs (pDCs), CD1c+ myeloid DCs (mDCs), and CD141+ mDCs among ESCC patients (n=60) were confirmed. Flurbiprofen was administered before skin incision and at the end of operation in group F (n=30), as well as placebo in group C (n=30). The postoperative suppressed percentages of pDCs, CD1c+ mDCs, and CD141+ mDCs increased significantly following the perioperative treatment with flurbiprofen. Flurbiprofen also significantly stimulated the postoperative IFN-f and IL-17 production, but inhibited the immunosuppressive IL-10 and TGF-β levels. Furthermore, flurbiprofen exerted a similar analgesic effect and brought a significantly less sufentanil consumption compared to group C. Taken together, flurbiprofen provided a short-term increase of postoperative naturally circulating DCs in ESCC patients. PMID:26959879

  12. Transcriptional profiling of dendritic cells matured in different osmolarities

    Directory of Open Access Journals (Sweden)

    Federica Chessa

    2016-03-01

    Full Text Available Tissue-specific microenvironments shape the fate of mononuclear phagocytes [1–3]. Interstitial osmolarity is a tissue biophysical parameter which considerably modulates the phenotype and function of dendritic cells [4]. In the present report we provide a detailed description of our experimental workflow and bioinformatic analysis applied to our gene expression dataset (GSE72174, aiming to investigate the influence of different osmolarity conditions on the gene expression signature of bone marrow-derived dendritic cells. We established a cell culture system involving murine bone marrow cells, cultured under different NaCl-induced osmolarity conditions in the presence of the dendritic cell growth factor GM-CSF. Gene expression analysis was applied to mature dendritic cells (day 7 developed in different osmolarities, with and without prior stimulation with the TLR2/4 ligand LPS.

  13. Metabolism Is Central to Tolerogenic Dendritic Cell Function

    Directory of Open Access Journals (Sweden)

    Wen Jing Sim

    2016-01-01

    Full Text Available Immunological tolerance is a fundamental tenant of immune homeostasis and overall health. Self-tolerance is a critical component of the immune system that allows for the recognition of self, resulting in hyporeactivity instead of immunogenicity. Dendritic cells are central to the establishment of dominant immune tolerance through the secretion of immunosuppressive cytokines and regulatory polarization of T cells. Cellular metabolism holds the key to determining DC immunogenic or tolerogenic cell fate. Recent studies have demonstrated that dendritic cell maturation leads to a shift toward a glycolytic metabolic state and preferred use of glucose as a carbon source. In contrast, tolerogenic dendritic cells favor oxidative phosphorylation and fatty acid oxidation. This dichotomous metabolic reprogramming of dendritic cells drives differential cellular function and plays a role in pathologies, such as autoimmune disease. Pharmacological alterations in metabolism have promising therapeutic potential.

  14. Follicular Dendritic Cell Sarcoma of the Abdomen: the Imaging Findings

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Tae Wook; Lee, Soon Jin; Song, Hye Jong [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2010-04-15

    Follicular dendritic cell sarcoma is a rare neoplasm that originates from follicular dendritic cells in lymphoid follicles. This disease usually involves the lymph nodes, and especially the head and neck area. Rarely, extranodal sites may be affected, including tonsil, the oral cavity, liver, spleen and the gastrointestinal tract. We report here on the imaging findings of follicular dendritic cell sarcoma of the abdomen that involved the retroperitoneal lymph nodes and colon. It shows as a well-defined, enhancing homogenous mass with internal necrosis and regional lymphadenopathy.

  15. Dendritic cells and their role in periodontal disease.

    Science.gov (United States)

    Wilensky, A; Segev, H; Mizraji, G; Shaul, Y; Capucha, T; Shacham, M; Hovav, A-H

    2014-03-01

    T cells, particularly CD4+ T cells, play a central role in both progression and control of periodontal disease, whereas the contribution of the various CD4+ T helper subsets to periodontal destruction remains controversial, the activation, and regulation of these cells is orchestrated by dendritic cells. As sentinels of the oral mucosa, dendritic cells encounter and capture oral microbes, then migrate to the lymph node where they regulate the differentiation of CD4+ T cells. It is thus clear that dendritic cells are of major importance in the course of periodontitis, as they hold the immunological cues delivered by the pathogen and the surrounding environment, allowing them to induce destructive immunity. In recent years, advanced immunological techniques and new mouse models have facilitated in vivo studies that have provided new insights into the developmental and functional aspects of dendritic cells. This progress has also benefited the characterization of oral dendritic cells, as well as to their function in periodontitis. Here, we provide an overview of the various gingival dendritic cell subsets and their distribution, while focusing on their role in periodontal bone loss.

  16. Tumor's other immune targets: dendritic cells.

    Science.gov (United States)

    Esche, C; Lokshin, A; Shurin, G V; Gastman, B R; Rabinowich, H; Watkins, S C; Lotze, M T; Shurin, M R

    1999-08-01

    The induction of apoptosis in T cells is one of several mechanisms by which tumors escape immune recognition. We have investigated whether tumors induce apoptosis in dendritic cells (DC) by co-culture of murine or human DC with different tumor cell lines for 4-48 h. Analysis of DC morphological features, JAM assay, TUNEL, caspase-3-like and transglutaminase activity, Annexin V binding, and DNA fragmentation assays revealed a time- and dose-dependent induction of apoptosis in DC by tumor-derived factors. This finding is both effector and target specific. The mechanism of tumor-induced DC apoptosis involved regulation of Bcl-2 and Bax expression. Double staining of both murine and human tumor tissues confirmed that tumor-associated DC undergo apoptotic death in vivo. DC isolated from tumor tissue showed significantly higher levels of apoptosis as determined by TUNEL assay when compared with DC isolated from spleen. These findings demonstrate that tumors induce apoptosis in DC and suggest a new mechanism of tumor escape from immune recognition. DC protection from apoptosis will lead to improvement of DC-based immunotherapies for cancer and other immune diseases.

  17. Differential Gene Expression in Thrombomodulin (TM; CD141)+ and TM− Dendritic Cell Subsets

    OpenAIRE

    Masaaki Toda; Zhifei Shao; Yamaguchi, Ken D.; Takehiro Takagi; Corina N D'Alessandro-Gabazza; Osamu Taguchi; Hugh Salamon; Leung, Lawrence L. K.; Gabazza, Esteban C.; John Morser

    2013-01-01

    Previously we have shown in a mouse model of bronchial asthma that thrombomodulin can convert immunogenic conventional dendritic cells into tolerogenic dendritic cells while inducing its own expression on their cell surface. Thrombomodulin(+) dendritic cells are tolerogenic while thrombomodulin(-) dendritic cells are pro-inflammatory and immunogenic. Here we hypothesized that thrombomodulin treatment of dendritic cells would modulate inflammatory gene expression. Murine bone marrow-derived de...

  18. CD163 positive subsets of blood dendritic cells

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Møller, Holger Jon; Moestrup, Søren Kragh

    2006-01-01

    CD163 and CD91 are scavenging receptors with highly increased expression during the differentiation of monocytes into the anti-inflammatory macrophage phenotype. In addition, CD91 is expressed in monocyte-derived dendritic cells (MoDCs), where the receptor is suggested to be important for interna......CD163 and CD91 are scavenging receptors with highly increased expression during the differentiation of monocytes into the anti-inflammatory macrophage phenotype. In addition, CD91 is expressed in monocyte-derived dendritic cells (MoDCs), where the receptor is suggested to be important...... for internalization of CD91-targeted antigens to be presented on the dendritic cell surface for T-cell stimulation. Despite their overlap in functionality, the expression of CD91 and CD163 has never been compared and the expression of CD163 in the monocyte-dendritic cell lineage is not yet characterized. CD163...

  19. Mycobacterium avium subspecies impair dendritic cell maturation.

    Science.gov (United States)

    Basler, Tina; Brumshagen, Christina; Beineke, Andreas; Goethe, Ralph; Bäumer, Wolfgang

    2013-10-01

    Mycobacterium avium ssp. paratuberculosis (MAP) causes Johne's disease, a chronic, granulomatous enteritis of ruminants. Dendritic cells (DC) of the gut are ideally placed to combat invading mycobacteria; however, little is known about their interaction with MAP. Here, we investigated the interaction of MAP and the closely related M. avium ssp. avium (MAA) with murine DC and the effect of infected macrophages on DC maturation. The infection of DC with MAP or MAA induced DC maturation, which differed to that of LPS as maturation was accompanied by higher production of IL-10 and lower production of IL-12. Treatment of maturing DC with supernatants from mycobacteria-infected macrophages resulted in impaired DC maturation, leading to a semi-mature, tolerogenic DC phenotype expressing low levels of MHCII, CD86 and TNF-α after LPS stimulation. Though the cells were not completely differentiated they responded with an increased IL-10 and a decreased IL-12 production. Using recombinant cytokines we provide evidence that the semi-mature DC phenotype results from a combination of secreted cytokines and released antigenic mycobacterial components of the infected macrophage. Our results indicate that MAP and MAA are able to subvert DC function directly by infecting and indirectly via the milieu created by infected macrophages.

  20. Deciphering dendritic cell heterogenity in immunity

    Directory of Open Access Journals (Sweden)

    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  1. Transcriptional regulation of dendritic cell diversity.

    Science.gov (United States)

    Chopin, Michaël; Allan, Rhys S; Belz, Gabrielle T

    2012-01-01

    Dendritic cells (DCs) are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration, and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These findings open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle - identification of similar DC populations in mouse and man - now sets the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  2. Dendritic Cells, Viruses, and the Development of Atopic Disease

    Directory of Open Access Journals (Sweden)

    Jonathan S. Tam

    2012-01-01

    Full Text Available Dendritic cells are important residents of the lung environment. They have been associated with asthma and other inflammatory diseases of the airways. In addition to their antigen-presenting functions, dendritic cells have the ability to modulate the lung environment to promote atopic disease. While it has long been known that respiratory viral infections associate with the development and exacerbation of atopic diseases, the exact mechanisms have been unclear. Recent studies have begun to show the critical importance of the dendritic cell in this process. This paper focuses on these data demonstrating how different populations of dendritic cells are capable of bridging the adaptive and innate immune systems, ultimately leading to the translation of viral illness into atopic disease.

  3. Activated protein C modulates the proinflammatory activity of dendritic cells

    Directory of Open Access Journals (Sweden)

    Matsumoto T

    2015-05-01

    Full Text Available Takahiro Matsumoto,1,2* Yuki Matsushima,1* Masaaki Toda,1 Ziaurahman Roeen,1 Corina N D'Alessandro-Gabazza,1,5 Josephine A Hinneh,1 Etsuko Harada,1,3 Taro Yasuma,4 Yutaka Yano,4 Masahito Urawa,1,5 Tetsu Kobayashi,5 Osamu Taguchi,5 Esteban C Gabazza1 1Department of Immunology, Mie University Graduate School of Medicine, Tsu, Mie Prefecture, 2BONAC Corporation, BIO Factory 4F, Fukuoka, 3Iwade Research Institute of Mycology, 4Department of Endocrinology, Diabetes and Metabolism, 5Department of Pulmonary and Critical Care Medicine, Mie University Graduate School of Medicine, Tsu, Mie Prefecture, Japan *These authors contributed equally to this work Background: Previous studies have demonstrated the beneficial activity of activated protein C in allergic diseases including bronchial asthma and rhinitis. However, the exact mechanism of action of activated protein C in allergies is unclear. In this study, we hypothesized that pharmacological doses of activated protein C can modulate allergic inflammation by inhibiting dendritic cells. Materials and methods: Dendritic cells were prepared using murine bone marrow progenitor cells and human peripheral monocytes. Bronchial asthma was induced in mice that received intratracheal instillation of ovalbumin-pulsed dendritic cells. Results: Activated protein C significantly increased the differentiation of tolerogenic plasmacytoid dendritic cells and the secretion of type I interferons, but it significantly reduced lipopolysaccharide-mediated maturation and the secretion of inflammatory cytokines in myeloid dendritic cells. Activated protein C also inhibited maturation and the secretion of inflammatory cytokines in monocyte-derived dendritic cells. Activated protein C-treated dendritic cells were less effective when differentiating naïve CD4 T-cells from Th1 or Th2 cells, and the cellular effect of activated protein C was mediated by its receptors. Mice that received adoptive transfer of activated protein C

  4. Dendritic cell-nerve clusters are sites of T cell proliferation in allergic airway inflammation.

    Science.gov (United States)

    Veres, Tibor Z; Shevchenko, Marina; Krasteva, Gabriela; Spies, Emma; Prenzler, Frauke; Rochlitzer, Sabine; Tschernig, Thomas; Krug, Norbert; Kummer, Wolfgang; Braun, Armin

    2009-03-01

    Interactions between T cells and dendritic cells in the airway mucosa precede secondary immune responses to inhaled antigen. The purpose of this study was to identify the anatomical locations where dendritic cell-T cell interactions occur, resulting in T cells activation by dendritic cells. In a mouse model of allergic airway inflammation, we applied whole-mount immunohistology and confocal microscopy to visualize dendritic cells and T cells together with nerves, epithelium, and smooth muscle in three dimensions. Proliferating T cells were identified by the detection of the incorporation of the nucleotide analogue 5-ethynyl-2'-deoxyuridine into the DNA. We developed a novel quantification method that enabled the accurate determination of cell-cell contacts in a semi-automated fashion. Dendritic cell-T cell interactions occurred beneath the smooth muscle layer, but not in the epithelium. Approximately 10% of the dendritic cells were contacted by nerves, and up to 4% of T cells formed clusters with these dendritic cells. T cells that were clustered with nerve-contacting dendritic cells proliferated only in the airways of mice with allergic inflammation but not in the airways of negative controls. Taken together, these results suggest that during the secondary immune response, sensory nerves influence dendritic cell-driven T cell activation in the airway mucosa.

  5. T Cells Capture Bacteria by Transinfection from Dendritic Cells.

    Science.gov (United States)

    Cruz-Adalia, Aranzazu; Ramírez-Santiago, Guillermo; Torres-Torresano, Mónica; Garcia-Ferreras, Raquel; Veiga Chacón, Esteban

    2016-01-13

    Recently, we have shown, contrary to what is described, that CD4(+) T cells, the paradigm of adaptive immune cells, capture bacteria from infected dendritic cells (DCs) by a process called transinfection. Here, we describe the analysis of the transinfection process, which occurs during the course of antigen presentation. This process was unveiled by using CD4(+) T cells from transgenic OTII mice, which bear a T cell receptor (TCR) specific for a peptide of ovoalbumin (OVAp), which therefore can form stable immune complexes with infected dendritic cells loaded with this specific OVAp. The dynamics of green fluorescent protein (GFP)-expressing bacteria during DC-T cell transmission can be monitored by live-cell imaging and the quantification of bacterial transinfection can be performed by flow cytometry. In addition, transinfection can be quantified by a more sensitive method based in the use of gentamicin, a non-permeable aminoglycoside antibiotic killing extracellular bacteria but not intracellular ones. This classical method has been used previously in microbiology to study the efficiency of bacterial infections. We hereby explain the protocol of the complete process, from the isolation of the primary cells to the quantification of transinfection.

  6. Organ-derived dendritic cells have differential effects on alloreactive T cells

    OpenAIRE

    Kim, Theo D.; Terwey, Theis H.; Zakrzewski, Johannes L; Suh, David; Kochman, Adam A.; Chen, Megan E.; King, Chris G.; Borsotti, Chiara; Grubin, Jeremy; Smith, Odette M.; Heller, Glenn; Liu, Chen; Murphy, George F.; Alpdogan, Onder; Marcel R. M. van den Brink

    2008-01-01

    Dendritic cells (DCs) are considered critical for the induction of graft-versus-host disease (GVHD) after bone marrow transplantation (BMT). In addition to their priming function, dendritic cells have been shown to induce organ-tropism through induction of specific homing molecules on T cells. Using adoptive transfer of CFSE-labeled cells, we first demonstrated that alloreactive T cells differentially up-regulate specific homing molecules in vivo. Host-type dendritic cells from the GVHD targe...

  7. Kicking off adaptive immunity: the discovery of dendritic cells

    OpenAIRE

    Katsnelson, Alla

    2006-01-01

    In 1973, Ralph Steinman and Zanvil Cohn discovered an unusual looking population of cells with an unprecedented ability to activate naive T cells. Dubbed “dendritic cells,” these cells are now known as the primary instigators of adaptive immunity.

  8. Nomenclature of monocytes and dendritic cells in blood

    NARCIS (Netherlands)

    L. Ziegler-Heitbrock (Loems); P. Ancuta (Petronela); S. Crowe (Suzanne); M. Dalod (Marc); V. Grau (Veronika); D.N. Hart (Derek); P.J. Leenen (Pieter); Y.J. Liu; G. MacPherson (Gordon); G.J. Randolph (Gwendalyn); J. Scherberich (Juergen); J. Schmitz (Juergen); K. Shortman (Ken); S. Sozzani (Silvano); H. Strobl (Herbert); M. Zembala (Marek); J.M. Austyn (Jonathan); M.B. Lutz (Manfred)

    2010-01-01

    textabstractMonocytes and cells of the dendritic cell lineage circulate in blood and eventually migrate into tissue where they further mature and serve various functions, most notably in immune defense. Over recent years these cells have been characterized in detail with the use of cell surface mark

  9. A Model of Dendritic Cell Therapy for Melanoma

    Directory of Open Access Journals (Sweden)

    Ami eRadunskaya

    2013-03-01

    Full Text Available Dendritic cells are a promising immunotherapy tool for boosting an individual's antigen specific immune response to cancer. We develop a mathematical model using differential and delay-differential equations to describe the interactions between dendritic cells, effector-immune cells and tumor cells. We account for the trafficking of immune cells between lymph, blood, and tumor compartments. Our model reflects experimental results both for dendritic-cell trafficking and for immune suppression of tumor growth in mice. In addition, in silico experiments suggest more effective immunotherapy treatment protocols can be achieved by modifying dose location and schedule. A sensitivity analysis of the model reveals which patient-specific parameters have the greatest impact on treatment efficacy.

  10. Plasmacytoid DCs regulate recall responses by rapid induction of IL-10 in memory T cells.

    Science.gov (United States)

    Kvale, Espen O; Fløisand, Yngvar; Lund-Johansen, Fridtjof; Rollag, Halvor; Farkas, Lorant; Ghanekar, Smita; Brandtzaeg, Per; Jahnsen, Frode L; Olweus, Johanna

    2007-04-15

    Dendritic cells (DCs) are believed to regulate T cell-mediated immunity primarily by directing differentiation of naive T cells. Here, we show that a large fraction of CD4(+) memory cells produce IL-10 within the first hours after interaction with plasmacytoid DCs (PDCs). In contrast, CD11c(+) DCs induce IFN-gamma and little IL-10. IL-10-secreting T cells isolated after 36 hours of culture with PDCs suppressed antigen-induced T-cell proliferation by an IL-10-dependent mechanism, but were distinct from natural and type 1 regulatory T cells. They proliferated strongly and continued to secrete IL-10 during expansion with PDCs, and after restimulation with immature monocyte-derived DCs or CD11c(+) DCs. The IL-10-producing T cells acquired the ability to secrete high levels of IFN-gamma after isolation and subsequent coculture with PDCs or CD11c(+) DCs. Compared to CD11c(+) DCs, PDCs were superior in their ability to selectively expand T cells that produced cytokines on repeated antigenic challenge. The DC-dependent differences in cytokine profiles were observed with viral recall antigen or staphylococcal enterotoxin B and were independent of extracellular type I interferon or IL-10. Our results show that DCs can regulate memory responses and that PDCs rapidly induce regulatory cytokines in effector T cells that can suppress bystander activity.

  11. Human intestinal dendritic cells as controllers of mucosal immunity

    Directory of Open Access Journals (Sweden)

    David Bernardo

    2013-06-01

    Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  12. Macrophages as APC and the dendritic cell myth.

    Science.gov (United States)

    Hume, David A

    2008-11-01

    Dendritic cells have been considered an immune cell type that is specialized for the presentation of Ag to naive T cells. Considerable effort has been applied to separate their lineage, pathways of differentiation, and effectiveness in Ag presentation from those of macrophages. This review summarizes evidence that dendritic cells are a part of the mononuclear phagocyte system and are derived from a common precursor, responsive to the same growth factors (including CSF-1), express the same surface markers (including CD11c), and have no unique adaptation for Ag presentation that is not shared by other macrophages.

  13. Functional limitations of plasmacytoid dendritic cells limit type I interferon, T cell responses and virus control in early life.

    Directory of Open Access Journals (Sweden)

    Elodie Belnoue

    Full Text Available Infant mortality from viral infection remains a major global health concern: viruses causing acute infections in immunologically mature hosts often follow a more severe course in early life, with prolonged or persistent viral replication. Similarly, the WE strain of lymphocytic choriomeningitis virus (LCMV-WE causes acute self-limiting infection in adult mice but follows a protracted course in infant animals, in which LCMV-specific CD8⁺ T cells fail to expand and control infection. By disrupting type I IFNs signaling in adult mice or providing IFN-α supplementation to infant mice, we show here that the impaired early life T cell responses and viral control result from limited early type I IFN responses. We postulated that plasmacytoid dendritic cells (pDC, which have been identified as one major source of immediate-early IFN-I, may not exert adult-like function in vivo in the early life microenvironment. We tested this hypothesis by studying pDC functions in vivo during LCMV infection and identified a coordinated downregulation of infant pDC maturation, activation and function: despite an adult-like in vitro activation capacity of infant pDCs, the expression of the E2-2 pDC master regulator (and of critical downstream antiviral genes such as MyD88, TLR7/TLR9, NF-κB, IRF7 and IRF8 is downregulated in vivo at baseline and during LCMV infection. A similar pattern was observed in response to ssRNA polyU, a model ligand of the TLR7 viral sensor. This suggests that the limited T cell-mediated defense against early life viral infections is largely attributable to / regulated by infant pDC responses and provides incentives for novel strategies to supplement or stimulate immediate-early IFN-α responses.

  14. Plasmacytoid dendritic cells are dispensable for noninfectious intestinal IgA responses in vivo.

    Science.gov (United States)

    Moro-Sibilot, Ludovic; This, Sebastien; Blanc, Pascal; Sanlaville, Amelien; Sisirak, Vanja; Bardel, Emilie; Boschetti, Gilles; Bendriss-Vermare, Nathalie; Defrance, Thierry; Dubois, Bertrand; Kaiserlian, Dominique

    2016-02-01

    Intestinal DCs orchestrate gut immune homeostasis by dampening proinflammatory T-cell responses and inducing anti-inflammatory IgA responses. Although no specific DC subset has been strictly assigned so far to govern IgA response, some candidate subsets emerge. In particular, plasmacytoid DCs (pDCs), which notoriously promote anti-viral immunity and T-cell tolerance to innocuous antigens (Ags), contribute to IgA induction in response to intestinal viral infection and promote T-cell-independent IgA responses in vitro. Here, using two transgenic mouse models, we show that neither short-term nor long-term pDC depletion alters IgA class switch recombination in Peyer's patches and frequency of IgA plasma cells in intestinal mucosa at steady state, even in the absence of T-cell help. In addition, pDCs are dispensable for induction of intestinal IgA plasma cells in response to oral immunization with T-cell-dependent or T-cell-independent Ags, and are not required for proliferation and IgA switch of Ag-specific B cells in GALT. These results show that pDCs are dispensable for noninfectious IgA responses, and suggest that various DC subsets may play redundant roles in the control of intestinal IgA responses.

  15. Murid herpesvirus-4 exploits dendritic cells to infect B cells.

    Science.gov (United States)

    Gaspar, Miguel; May, Janet S; Sukla, Soumi; Frederico, Bruno; Gill, Michael B; Smith, Christopher M; Belz, Gabrielle T; Stevenson, Philip G

    2011-11-01

    Dendritic cells (DCs) play a central role in initiating immune responses. Some persistent viruses infect DCs and can disrupt their functions in vitro. However, these viruses remain strongly immunogenic in vivo. Thus what role DC infection plays in the pathogenesis of persistent infections is unclear. Here we show that a persistent, B cell-tropic gamma-herpesvirus, Murid Herpesvirus-4 (MuHV-4), infects DCs early after host entry, before it establishes a substantial infection of B cells. DC-specific virus marking by cre-lox recombination revealed that a significant fraction of the virus latent in B cells had passed through a DC, and a virus attenuated for replication in DCs was impaired in B cell colonization. In vitro MuHV-4 dramatically altered the DC cytoskeleton, suggesting that it manipulates DC migration and shape in order to spread. MuHV-4 therefore uses DCs to colonize B cells.

  16. Avian dendritic cells: Phenotype and ontogeny in lymphoid organs.

    Science.gov (United States)

    Nagy, Nándor; Bódi, Ildikó; Oláh, Imre

    2016-05-01

    Dendritic cells (DC) are critically important accessory cells in the innate and adaptive immune systems. Avian DCs were originally identified in primary and secondary lymphoid organs by their typical morphology, displaying long cell processes with cytoplasmic granules. Several subtypes are known. Bursal secretory dendritic cells (BSDC) are elongated cells which express vimentin intermediate filaments, MHC II molecules, macrophage colony-stimulating factor 1 receptor (CSF1R), and produce 74.3+ secretory granules. Avian follicular dendritic cells (FDC) highly resemble BSDC, express the CD83, 74.3 and CSF1R molecules, and present antigen in germinal centers. Thymic dendritic cells (TDC), which express 74.3 and CD83, are concentrated in thymic medulla while interdigitating DC are found in T cell-rich areas of secondary lymphoid organs. Avian Langerhans cells are a specialized 74.3-/MHC II+ cell population found in stratified squamous epithelium and are capable of differentiating into 74.3+ migratory DCs. During organogenesis hematopoietic precursors of DC colonize the developing lymphoid organ primordia prior to immigration of lymphoid precursor cells. This review summarizes our current understanding of the ontogeny, cytoarchitecture, and immunophenotype of avian DC, and offers an antibody panel for the in vitro and in vivo identification of these heterogeneous cell types.

  17. Detection of Langerhans cells and plasmacytoid dendritic cells in condyloma acuminatum lesions of patients%尖锐湿疣患者皮损中朗格汉斯细胞和浆细胞样树突细胞的检测

    Institute of Scientific and Technical Information of China (English)

    朱小霞; 周强; 程浩; 朱红明

    2015-01-01

    Objective To investigate the possible roles of Langerhans cells(LCs) and plasmacytoid dendritic cells(pDCs)in the pathogenesis of condyloma acuminatum(CA). Methods Tissue specimens were obtained from the lesions of 23 patients with CA and from perilesional normal skin of 13 of the 23 patients. The expressions and distribution of CD1a, CD2AP and CD123 were analyzed using the streptavidin-peroxidase (SP) immunohistochemical method. Statistical analysis was carried out to compare the density and percentage of CD1a + LCs, CD2AP + pDCs and CD123 +pDCs between lesional skin and perilesional normal skin. Results Most CD1a + LCs were observed in the prickle cell layer of the epidermis, and a few in the papillary layer of the dermis. There was no significant difference in the density or percentage of CD1a+ LCs in the epidermis or dermis between the lesional and perilesional skin specimens (all P > 0.05). CD2AP + pDCs and CD123 + pDCs were distributed mainly in the papillary layer of the dermis, and their density and percentage were significantly higher in the lesional than in the perilesional skin specimens (all P 0.05)。CD2AP+pDC、CD123+pDC 主要位于真皮乳头层,CA 患者皮损中 CD2AP+pDC、CD123+pDC 的密度和阳性率均比边缘正常对照组显著增高(P <0.05)。结论人乳头瘤病毒感染影响局部黏膜的 pDC 数量,LC 数量未见变化。

  18. Intratumoral Dendritic Cells and Chemoradiation for the Treatment of Murine Squamous Cell Carcinoma

    OpenAIRE

    Moyer, Jeffrey S.; Li, Ji; Wei, Shuang; Teitz-Tennenbaum, Seagal; Chang, Alfred E

    2008-01-01

    Dendritic cells are potent antigen presenting cells that have been shown to have significant antitumor effects in vitro and in vivo. However, the therapeutic efficacy of dendritic cells as an immunotherapeutic treatment has been limited by both immunologic tolerance and active immunosuppression in the tumor microenvironment. To address this problem, we examined the ability of concurrent systemic chemotherapy and local, fractionated radiation to augment intratumoral dendritic cell injections i...

  19. Involvement of dendritic cells in autoimmune diseases in children

    Directory of Open Access Journals (Sweden)

    Reed Ann M

    2007-07-01

    Full Text Available Abstract Dendritic cells (DCs are professional antigen-presenting cells that are specialized in the uptake of antigens and their transport from peripheral tissues to the lymphoid organs. Over the last decades, the properties of DCs have been intensely studied and much knowledge has been gained about the role of DCs in various diseases and health conditions where the immune system is involved, particularly in cancer and autoimmune disorders. Emerging clues in autoimmune diseases, suggest that dendritic cell dysregulation might be involved in the development of various autoimmune disorders in both adults and children. However, studies investigating a possible contribution of DCs in autoimmune diseases in the pediatric population alone are scanty. The purpose of this review is to give a general overview of the current literature on the relevance of dendritic cells in the most common autoimmune conditions of childhood.

  20. Dendritic cell SIRPα regulates homeostasis of dendritic cells in lymphoid organs.

    Science.gov (United States)

    Washio, Ken; Kotani, Takenori; Saito, Yasuyuki; Respatika, Datu; Murata, Yoji; Kaneko, Yoriaki; Okazawa, Hideki; Ohnishi, Hiroshi; Fukunaga, Atsushi; Nishigori, Chikako; Matozaki, Takashi

    2015-06-01

    Signal regulatory protein α (SIRPα), an immunoglobulin superfamily protein that is expressed predominantly in myeloid lineage cells such as dendritic cells (DCs) or macrophages, mediates cell-cell signaling. In the immune system, SIRPα is thought to be important for homeostasis of DCs, but it remains unclear whether SIRPα intrinsic to DCs is indeed indispensable for such functional role. Thus, we here generated the mice, in which SIRPα was specifically ablated in CD11c(+) DCs (Sirpa(Δ) (DC) ). Sirpa(Δ) (DC) mice manifested a marked reduction of CD4(+) CD8α(-) conventional DCs (cDCs) in the secondary lymphoid organs, as well as of Langerhans cells in the epidermis. Such reduction of cDCs in Sirpa(Δ) (DC) mice was comparable to that apparent with the mice, in which SIRPα was systemically ablated. Expression of SIRPα in DCs was well correlated with that of either endothelial cell-selective adhesion molecule (ESAM) or Epstein-Barr virus-induced molecule 2 (EBI2), both of which were also implicated in the regulation of DC homeostasis. Indeed, ESAM(+) or EBI2(+) cDCs were markedly reduced in the spleen of Sirpa(Δ) (DC) mice. Thus, our results suggest that SIRPα intrinsic to CD11c(+) DCs is essential for homeostasis of cDCs in the secondary lymphoid organs and skin.

  1. Dendritic Cells in Kidney Transplant Biopsy Samples Are Associated with T Cell Infiltration and Poor Allograft Survival.

    Science.gov (United States)

    Batal, Ibrahim; De Serres, Sacha A; Safa, Kassem; Bijol, Vanesa; Ueno, Takuya; Onozato, Maristela L; Iafrate, A John; Herter, Jan M; Lichtman, Andrew H; Mayadas, Tanya N; Guleria, Indira; Rennke, Helmut G; Najafian, Nader; Chandraker, Anil

    2015-12-01

    Progress in long-term renal allograft survival continues to lag behind the progress in short-term transplant outcomes. Dendritic cells are the most efficient antigen-presenting cells, but surprisingly little attention has been paid to their presence in transplanted kidneys. We used dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin as a marker of dendritic cells in 105 allograft biopsy samples from 105 kidney transplant recipients. High dendritic cell density was associated with poor allograft survival independent of clinical variables. Moreover, high dendritic cell density correlated with greater T cell proliferation and poor outcomes in patients with high total inflammation scores, including inflammation in areas of tubular atrophy. We then explored the association between dendritic cells and histologic variables associated with poor prognosis. Multivariate analysis revealed an independent association between the densities of dendritic cells and T cells. In biopsy samples with high dendritic cell density, electron microscopy showed direct physical contact between infiltrating lymphocytes and cells that have the ultrastructural morphologic characteristics of dendritic cells. The origin of graft dendritic cells was sought in nine sex-mismatched recipients using XY fluorescence in situ hybridization. Whereas donor dendritic cells predominated initially, the majority of dendritic cells in late allograft biopsy samples were of recipient origin. Our data highlight the prognostic value of dendritic cell density in allograft biopsy samples, suggest a new role for these cells in shaping graft inflammation, and provide a rationale for targeting dendritic cell recruitment to promote long-term allograft survival.

  2. Modified vaccinia virus Ankara triggers type I IFN production in murine conventional dendritic cells via a cGAS/STING-mediated cytosolic DNA-sensing pathway.

    Directory of Open Access Journals (Sweden)

    Peihong Dai

    2014-04-01

    Full Text Available Modified vaccinia virus Ankara (MVA is an attenuated poxvirus that has been engineered as a vaccine against infectious agents and cancers. Our goal is to understand how MVA modulates innate immunity in dendritic cells (DCs, which can provide insights to vaccine design. In this study, using murine bone marrow-derived dendritic cells, we assessed type I interferon (IFN gene induction and protein secretion in response to MVA infection. We report that MVA infection elicits the production of type I IFN in murine conventional dendritic cells (cDCs, but not in plasmacytoid dendritic cells (pDCs. Transcription factors IRF3 (IFN regulatory factor 3 and IRF7, and the positive feedback loop mediated by IFNAR1 (IFN alpha/beta receptor 1, are required for the induction. MVA induction of type I IFN is fully dependent on STING (stimulator of IFN genes and the newly discovered cytosolic DNA sensor cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase. MVA infection of cDCs triggers phosphorylation of TBK1 (Tank-binding kinase 1 and IRF3, which is abolished in the absence of cGAS and STING. Furthermore, intravenous delivery of MVA induces type I IFN in wild-type mice, but not in mice lacking STING or IRF3. Treatment of cDCs with inhibitors of endosomal and lysosomal acidification or the lysosomal enzyme Cathepsin B attenuated MVA-induced type I IFN production, indicating that lysosomal enzymatic processing of virions is important for MVA sensing. Taken together, our results demonstrate a critical role of the cGAS/STING-mediated cytosolic DNA-sensing pathway for type I IFN induction in cDCs by MVA. We present evidence that vaccinia virulence factors E3 and N1 inhibit the activation of IRF3 and the induction of IFNB gene in MVA-infected cDCs.

  3. Modified vaccinia virus Ankara triggers type I IFN production in murine conventional dendritic cells via a cGAS/STING-mediated cytosolic DNA-sensing pathway.

    Science.gov (United States)

    Dai, Peihong; Wang, Weiyi; Cao, Hua; Avogadri, Francesca; Dai, Lianpan; Drexler, Ingo; Joyce, Johanna A; Li, Xiao-Dong; Chen, Zhijian; Merghoub, Taha; Shuman, Stewart; Deng, Liang

    2014-04-01

    Modified vaccinia virus Ankara (MVA) is an attenuated poxvirus that has been engineered as a vaccine against infectious agents and cancers. Our goal is to understand how MVA modulates innate immunity in dendritic cells (DCs), which can provide insights to vaccine design. In this study, using murine bone marrow-derived dendritic cells, we assessed type I interferon (IFN) gene induction and protein secretion in response to MVA infection. We report that MVA infection elicits the production of type I IFN in murine conventional dendritic cells (cDCs), but not in plasmacytoid dendritic cells (pDCs). Transcription factors IRF3 (IFN regulatory factor 3) and IRF7, and the positive feedback loop mediated by IFNAR1 (IFN alpha/beta receptor 1), are required for the induction. MVA induction of type I IFN is fully dependent on STING (stimulator of IFN genes) and the newly discovered cytosolic DNA sensor cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase). MVA infection of cDCs triggers phosphorylation of TBK1 (Tank-binding kinase 1) and IRF3, which is abolished in the absence of cGAS and STING. Furthermore, intravenous delivery of MVA induces type I IFN in wild-type mice, but not in mice lacking STING or IRF3. Treatment of cDCs with inhibitors of endosomal and lysosomal acidification or the lysosomal enzyme Cathepsin B attenuated MVA-induced type I IFN production, indicating that lysosomal enzymatic processing of virions is important for MVA sensing. Taken together, our results demonstrate a critical role of the cGAS/STING-mediated cytosolic DNA-sensing pathway for type I IFN induction in cDCs by MVA. We present evidence that vaccinia virulence factors E3 and N1 inhibit the activation of IRF3 and the induction of IFNB gene in MVA-infected cDCs.

  4. Phenotypical and functional characterization of clinical-grade dendritic cells.

    NARCIS (Netherlands)

    Vries, I.J.M. de; Adema, G.J.; Punt, C.J.A.; Figdor, C.G.

    2005-01-01

    Dendritic cells (DC) are the most potent antigen-presenting cells and form a promising new treatment modality. Fully activated DC loaded with antigen are very useful in stimulating immune responses, in particular those to combat cancer. Immature DC can either cause immunological tolerance or induce

  5. Dendritic cells and their role in tumor immunosurveillance

    NARCIS (Netherlands)

    Strioga, M.M.; Schijns, V.E.J.C.; Powell, D.J.; Pasukoniene, V.; Dobrovolskiene, N.T.; Michalek, J.

    2013-01-01

    Dendritic cells (DCs) comprise a heterogeneous population of cells that play a key role in initiating, directing and regulating adaptive immune responses, including those critically involved in tumor immunosurveillance. As a riposte to the central role of DCs in the generation of antitumor immune re

  6. 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

  7. IL-10 control of dendritic cells in the skin

    NARCIS (Netherlands)

    B.E. Clausen (Bjorn); M.J.H. Girard-Madoux (Mathilde)

    2013-01-01

    textabstractInterleukin-10 (IL-10) is a potent immunomodulatory cytokine, whose cellular targets have not yet been precisely identified. Mice bearing a dendritic cell (DC)-specific defect in the IL-10 receptor mice exhibit exaggerated T-cell reactivation in the skin, highlighting a key function of D

  8. Dendritic cell maturation results in pronounced changes in glycan expression affecting recognition by siglecs and galectins

    NARCIS (Netherlands)

    Bax, Marieke; Garcia-Vallejo, Juan J.; Jang-Lee, Jihye; North, Simon J.; Gilmartin, Tim J.; Hernandez, Gilberto; Crocker, Paul R.; Leffler, Hakon; Head, Steven R.; Haslam, Stuart M.; Dell, Anne; van Kooyk, Yvette

    2007-01-01

    Dendritic cells (DC) are the most potent APC in the organism. Immature dendritic cells (iDC) reside in the tissue where they capture pathogens whereas mature dendritic cells (mDC) are able to activate T cells in the lymph node. This dramatic functional change is mediated by an important genetic repr

  9. Plasmacytoid dendritic cells mediate anti-inflammatory responses to a gut commensal molecule via both innate and adaptive mechanisms.

    Science.gov (United States)

    Dasgupta, Suryasarathi; Erturk-Hasdemir, Deniz; Ochoa-Reparaz, Javier; Reinecker, Hans-Christian; Kasper, Dennis L

    2014-04-09

    Polysaccharide A (PSA), the archetypical immunomodulatory molecule of the gut commensal Bacteroides fragilis, induces regulatory T cells to secrete the anti-inflammatory cytokine interleukin-10 (IL-10). The cellular mediators of PSA's immunomodulatory properties are incompletely understood. In a mouse model of colitis, we find that PSA requires both innate and adaptive immune mechanisms to generate protection. Plasmacytoid DCs (PDCs) exposed to PSA do not produce proinflammatory cytokines, but instead they specifically stimulate IL-10 secretion by CD4+ T cells and efficiently mediate PSA-afforded immunoprotection. PSA induces and preferentially ligates Toll-like receptor 2 on PDCs but not on conventional DCs. Compared with other TLR2 ligands, PSA is better at enhancing PDC expression of costimulatory molecules required for protection against colitis. PDCs can thus orchestrate the beneficial immunoregulatory interaction of commensal microbial molecules, such as PSA, through both innate and adaptive immune mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Blastic plasmacytoid dendritic cell neoplasm with absolute monocytosis at presentation

    Directory of Open Access Journals (Sweden)

    Jaworski JM

    2015-02-01

    Full Text Available Joseph M Jaworski,1,2 Vanlila K Swami,1 Rebecca C Heintzelman,1 Carrie A Cusack,3 Christina L Chung,3 Jeremy Peck,3 Matthew Fanelli,3 Micheal Styler,4 Sanaa Rizk,4 J Steve Hou1 1Department of Pathology and Laboratory Medicine, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 2Department of Pathology, Mercy Fitzgerald Hospital, Darby, PA, USA; 3Department of Dermatology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 4Department of Hematology/Oncology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA Abstract: Blastic plasmacytoid dendritic cell neoplasm is an uncommon malignancy derived from precursors of plasmacytoid dendritic cells. Nearly all patients present initially with cutaneous manifestations, with many having extracutaneous disease additionally. While response to chemotherapy initially is effective, relapse occurs in most, with a leukemic phase ultimately developing. The prognosis is dismal. While most of the clinical and pathologic features are well described, the association and possible prognostic significance between peripheral blood absolute monocytosis (>1.0 K/µL and blastic plasmacytoid dendritic cell neoplasm have not been reported. We report a case of a 68-year-old man who presented with a rash for 4–5 months. On physical examination, there were multiple, dull-pink, indurated plaques on the trunk and extremities. Complete blood count revealed thrombocytopenia, absolute monocytosis of 1.7 K/µL, and a negative flow cytometry study. Biopsy of an abdominal lesion revealed typical features of blastic plasmacytoid dendritic cell neoplasm. Patients having both hematologic and nonhematologic malignancies have an increased incidence of absolute monocytosis. Recent studies examining Hodgkin and non-Hodgkin lymphoma patients have suggested that this is a negative prognostic factor. The association between

  11. Dendritic cells and immuno-modulation in autoimmune arthritis

    OpenAIRE

    Spiering, R.

    2013-01-01

    The immune system consists of a broad array of immune cells to protect the body against invasive pathogenic microorganisms. Immune responses should however, be tightly controlled to ensure tolerance to the body’s own cells and proteins in order to limit damage to the host own cells and tissue. Autoimmune diseases can arise when the balance between pathogen-driven immunity (inflammatory immune response) and tolerance (regulatory immune response) to self products is dysregulated. Dendritic cell...

  12. Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

    OpenAIRE

    Julio Aliberti

    2016-01-01

    Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response...

  13. File list: ALL.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: Oth.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  15. File list: InP.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  20. File list: Pol.Bld.10.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  2. File list: ALL.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  6. File list: InP.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  10. File list: ALL.Bld.10.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  11. File list: Unc.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  12. File list: Oth.Bld.05.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  14. File list: Oth.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  1. File list: ALL.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  2. File list: ALL.Bld.10.AllAg.Dendritic_Cells [Chip-atlas[Archive

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  11. Recognition of enteroinvasive Escherichia coli and Shigella flexneri by dendritic cells: distinct dendritic cell activation states

    Directory of Open Access Journals (Sweden)

    Ana Carolina Ramos Moreno

    2012-02-01

    Full Text Available The innate and adaptive immune responses of dendritic cells (DCs to enteroinvasive Escherichia coli (EIEC infection were compared with DC responses to Shigella flexneri infection. EIEC triggered DCs to produce interleukin (IL-10, IL-12 and tumour necrosis factor (TNF-α, whereas S. flexneri induced only the production of TNF-α. Unlike S. flexneri, EIEC strongly increased the expression of toll like receptor (TLR-4 and TLR-5 in DCs and diminished the expression of co-stimulatory molecules that may cooperate to inhibit CD4+ T-lymphocyte proliferation. The inflammation elicited by EIEC seems to be related to innate immunity both because of the aforementioned results and because only EIEC were able to stimulate DC transmigration across polarised Caco-2 cell monolayers, a mechanism likely to be associated with the secretion of CC chemokine ligands (CCL20 and TNF-α. Understanding intestinal DC biology is critical to unravelling the infection strategies of EIEC and may aid in the design of treatments for infectious diseases.

  12. Slowing down light using a dendritic cell cluster metasurface waveguide

    Science.gov (United States)

    Fang, Z. H.; Chen, H.; Yang, F. S.; Luo, C. R.; Zhao, X. P.

    2016-11-01

    Slowing down or even stopping light is the first task to realising optical information transmission and storage. Theoretical studies have revealed that metamaterials can slow down or even stop light; however, the difficulty of preparing metamaterials that operate in visible light hinders progress in the research of slowing or stopping light. Metasurfaces provide a new opportunity to make progress in such research. In this paper, we propose a dendritic cell cluster metasurface consisting of dendritic structures. The simulation results show that dendritic structure can realise abnormal reflection and refraction effects. Single- and double-layer dendritic metasurfaces that respond in visible light were prepared by electrochemical deposition. Abnormal Goos-Hänchen (GH) shifts were experimentally obtained. The rainbow trapping effect was observed in a waveguide constructed using the dendritic metasurface sample. The incident white light was separated into seven colours ranging from blue to red light. The measured transmission energy in the waveguide showed that the energy escaping from the waveguide was zero at the resonant frequency of the sample under a certain amount of incident light. The proposed metasurface has a simple preparation process, functions in visible light, and can be readily extended to the infrared band and communication wavelengths.

  13. Semaphorin 7A Promotes Chemokine-Driven Dendritic Cell Migration

    NARCIS (Netherlands)

    van Rijn, Anoek; Paulis, Leonie; te Riet, Joost; Vasaturo, Angela; Reinieren-Beeren, Inge; van der Schaaf, Alie; Kuipers, Arthur J.; Schulte, Luuk P.; Jongbloets, Bart C.; Pasterkamp, R. Jeroen; Figdor, Carl G.; van Spriel, Annemiek B.; Buschow, Sonja I.

    2016-01-01

    Dendritic cell (DC) migration is essential for efficient host defense against pathogens and cancer, as well as for the efficacy of DC-based immunotherapies. However, the molecules that induce the migratory phenotype of DCs are poorly defined. Based on a largescale proteome analysis of maturing DCs,

  14. Lung Dendritic cells: Targets for therapy in allergic disease

    NARCIS (Netherlands)

    B.N.M. Lambrecht (Bart)

    2008-01-01

    textabstractDendritic cells are crucial in determining the functional outcome of allergen encounter in the lung. Antigen presentation by myeloid DCs leads to Th2 sensitization typical of allergic disease, whereas antigen presentation by plasmacytoid DCs serves to dampen inflammation. It is increasin

  15. Migration of dendritic cell based cancer vaccines: in vivo veritas?

    NARCIS (Netherlands)

    Adema, G.J.; Vries, I.J.M. de; Punt, C.J.A.; Figdor, C.G.

    2005-01-01

    Ex vivo generated cancer vaccines based on dendritic cells (DCs) are currently applied in the clinic. The migration of DCs from the tissues to the lymph nodes is tightly controlled and involves many different mediators and their receptors. A recent study demonstrated that the rate of migration of

  16. Multimodal imaging of nanovaccine carriers targeted to human dendritic cells

    NARCIS (Netherlands)

    Cruz, L.J.; Tacken, P.J.; Bonetto, F.J.; Buschow, S.I.; Croes, H.J.E.; Wijers-Rouw, M.J.P.; Vries, I.J.M. de; Figdor, C.G.

    2011-01-01

    Dendritic cells (DCs) are key players in the initiation of adaptive immune responses and are currently exploited in immunotherapy against cancer and infectious diseases. The targeted delivery of nanovaccine particles (NPs) to DCs in vivo is a promising strategy to enhance immune responses. Here, tar

  17. Monocyte-derived dendritic cells in bipolar disorder

    NARCIS (Netherlands)

    Knijff, EM; Ruwhof, C; de Wit, HJ; Kupka, RW; Vonk, R; Akkerhuis, GW; Nolen, WA; Drexhage, HA

    2006-01-01

    Background: Dendritic cells (DC) are key regulators of the immune system, which is compromised in patients with bipolar disorder. We sought to study monocyte-derived DC in bipolar disorder. Methods: Monocytes purified from blood collected from DSM-IV bipolar disorder outpatients (n = 53, 12 without

  18. Interaction of classical swine fever virus with dendritic cells

    NARCIS (Netherlands)

    Carrasco, C.P.; Rigden, R.C.; Vincent, I.E.; Balmelli, C.; Ceppi, M.; Bauhofer, O.; Tache, V.; Hjertner, B.; McNeilly, F.; Gennip, van H.G.P.; McCullough, K.C.; Summerfield, A.

    2004-01-01

    Functional disruption of dendritic cells (DCs) is an important strategy for viral pathogens to evade host defences. Monocytotropic viruses such as classical swine fever virus (CSFV) could employ such a mechanism, since the virus can suppress immune responses and induce apoptosis without infecting ly

  19. Tolerogenic dendritic cells for regulatory T cell induction in man

    Directory of Open Access Journals (Sweden)

    Verena eRaker

    2015-11-01

    Full Text Available Dendritic cells are (DC highly specialized professional antigen-presenting cells (APC that regulate immune responses, maintaining the balance between tolerance and immunity. Mechanisms via which they can promote central and peripheral tolerance include clonal deletion, inhibition of memory T cell responses, T cell anergy and induction of regulatory T cells. These properties have led to the analysis of human tolerogenic DC as a therapeutic strategy for induction or re-establishment of tolerance. In the recent years, numerous protocols for the generation of human tolerogenic DC have been developed and their tolerogenic mechanisms, including induction of regulatory T cells, are relatively well understood. Phase I trials have been conducted in autoimmune disease, with results that emphasize the feasibility and safety of treatments with tolerogenic DC. Therefore, the scientific rationale for the use of tolerogenic DC therapy in the fields of transplantation medicine and allergic and autoimmune diseases is strong. This review will give an overview on efforts and protocols to generate human tolerogenic DC with focus on IL-10-modulated DC as inducers of regulatory T cells and discuss their clinical applications and challenges faced in further developing this form of immunotherapy.

  20. Cancer Vaccine by Fusions of Dendritic and Cancer Cells

    OpenAIRE

    Shigeo Koido; Eiichi Hara; Sadamu Homma; Yoshihisa Namiki; Toshifumi Ohkusa; Jianlin Gong; Hisao Tajiri

    2010-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Therefore, their use for the active immunotherapy against cancers has been studied with considerable interest. The fusion of DCs with whole tumor cells represents in many ways an ideal approach to deliver, process, and subsequently present a broad array of tumor-associated antigens, including those yet to be unidentified, in the context of DCs-derived...

  1. Dendritic web - A viable material for silicon solar cells

    Science.gov (United States)

    Seidensticker, R. G.; Scudder, L.; Brandhorst, H. W., Jr.

    1975-01-01

    The dendritic web process is a technique for growing thin silicon ribbon from liquid silicon. The material is suitable for solar cell fabrication and, in fact, cells fabricated on web material are equivalent in performance to cells fabricated on Czochralski-grown material. A recently concluded study has delineated the thermal requirements for silicon web crucibles, and a detailed conceptual design has been developed for a laboratory growth apparatus.

  2. Loss of CD103~+ intestinal dendritic cells during colonic inflammation

    Institute of Scientific and Technical Information of China (English)

    Ulrike; G; Strauch; Nicole; Grunwald; Florian; Obermeier; Sonja; Gürster; Heiko; C; Rath

    2010-01-01

    AIM:To investigate possible differences in dendritic cells(DC)within intestinal tissue of mice before and after induction of colitis. METHODS:Mucosal DC derived from intestinal tissue,as well as from mesenteric lymph nodes and spleen,were analyzed by fluorescence activated cell sorting(FACS) analysis.Supernatants of these cells were analyzed for secretion of different pro-and anti-inflammatory cytokines. Immunohistochemistry and immunofluorescence were performed on cryosections of mucosal tissue derived fro...

  3. Acute myeloid dendritic cell leukaemia with specific cutaneous involvement: a diagnostic challenge.

    Science.gov (United States)

    Ferran, M; Gallardo, F; Ferrer, A M; Salar, A; Pérez-Vila, E; Juanpere, N; Salgado, R; Espinet, B; Orfao, A; Florensa, L; Pujol, R M

    2008-05-01

    Myeloid or type 1 dendritic cell leukaemia is an exceedingly rare haematopoietic neoplasm characterized by a specific immunophenotypic profile close to plasmacytoid dendritic cell and acute myelogenous leukaemia. A 77-year-old man presenting specific cutaneous infiltration by myeloid dendritic cell leukaemia is reported. The clinical features as well as the cutaneous histopathological and immunohistochemical features led to the initial diagnosis of CD4+/CD56+ haematodermic neoplasm. However, extensive immunophenotypic studies performed from peripheral blood blasts disclosed that leukaemic cells expressed myeloid dendritic cell markers, confirming the diagnosis. The diagnostic difficulties of specific cutaneous involvement by myeloid dendritic cell leukaemia on the basis of routine histopathological and immunohistochemical features are highlighted.

  4. Dendritic Cells and HIV-1 Trans-Infection

    Directory of Open Access Journals (Sweden)

    David McDonald

    2010-08-01

    Full Text Available Dendritic cells initiate and sustain immune responses by migrating to sites of pathogenic insult, transporting antigens to lymphoid tissues and signaling immune specific activation of T cells through the formation of the immunological synapse. Dendritic cells can also transfer intact, infectious HIV-1 to CD4 T cells through an analogous structure, the infectious synapse. This replication independent mode of HIV-1 transmission, known as trans-infection, greatly increases T cell infection in vitro and is thought to contribute to viral dissemination in vivo. This review outlines the recent data defining the mechanisms of trans-infection and provides a context for the potential contribution of trans-infection in HIV-1 disease.

  5. Dendritic Cell Apoptosis and the Pathogenesis of Dengue

    Directory of Open Access Journals (Sweden)

    Lysangela R. Alves

    2012-11-01

    Full Text Available Dengue viruses and other members of the Flaviviridae family are emerging human pathogens. Dengue is transmitted to humans by Aedes aegypti female mosquitoes. Following infection through the bite, cells of the hematopoietic lineage, like dendritic cells, are the first targets of dengue virus infection. Dendritic cells (DCs are key antigen presenting cells, sensing pathogens, processing and presenting the antigens to T lymphocytes, and triggering an adaptive immune response. Infection of DCs by dengue virus may induce apoptosis, impairing their ability to present antigens to T cells, and thereby contributing to dengue pathogenesis. This review focuses on general mechanisms by which dengue virus triggers apoptosis, and possible influence of DC-apoptosis on dengue disease severity.

  6. Direction selectivity is computed by active dendritic integration in retinal ganglion cells.

    Science.gov (United States)

    Sivyer, Benjamin; Williams, Stephen R

    2013-12-01

    Active dendritic integration is thought to enrich the computational power of central neurons. However, a direct role of active dendritic processing in the execution of defined neuronal computations in intact neural networks has not been established. Here we used multi-site electrophysiological recording techniques to demonstrate that active dendritic integration underlies the computation of direction selectivity in rabbit retinal ganglion cells. Direction-selective retinal ganglion cells fire action potentials in response to visual image movement in a preferred direction. Dendritic recordings revealed that preferred-direction moving-light stimuli led to dendritic spike generation in terminal dendrites, which were further integrated and amplified as they spread through the dendritic arbor to the axon to drive action potential output. In contrast, when light bars moved in a null direction, synaptic inhibition vetoed neuronal output by directly inhibiting terminal dendritic spike initiation. Active dendritic integration therefore underlies a physiologically engaged circuit-based computation in the retina.

  7. Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells.

    Science.gov (United States)

    Zeybek, N Dilara; Asan, Esin; Erbil, A Hakan; Dagdeviren, Attila

    2008-01-01

    Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p=0.008, 0.008, 0.002 and <0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p=0.015, <0.0009 and <0.0009, respectively). Our study demonstrates that both peptide- and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

  8. Two cases of extranodal follicular dendritic cell sarcoma

    Institute of Scientific and Technical Information of China (English)

    王坚; 孔蕴仪; 陆洪芬; 许越香

    2003-01-01

    @@ Follicular dendritic cell (FDC) is an essential component of the nonlymphoid, nonphagocytic immunoaccessory reticulum cells of the peripheral lymphoid tissue.1 Follicular dendritic cell sarcoma (FDCs) are confined largely to the primary and secondary B-cell follicles, where they form a tight interlacing meshwork. They play a role in the capture and presentation of antigens, generation and regulation of immune complexes. FDCs can be recognized morphologically by their indistinct cellular borders, pale eosinophilic cytoplasm, round-to-ovoid nuclei with delicate nuclear membranes and clear-to-vesicular chromatin with inconspicuous or small nucleoli. FDCs are best identified through immunostaining using CD21, CD35, R4/23, KiM4, KiM4p and Ki-FDC1p.

  9. Dendritic Kv3.3 potassium channels in cerebellar purkinje cells regulate generation and spatial dynamics of dendritic Ca2+ spikes.

    Science.gov (United States)

    Zagha, Edward; Manita, Satoshi; Ross, William N; Rudy, Bernardo

    2010-06-01

    Purkinje cell dendrites are excitable structures with intrinsic and synaptic conductances contributing to the generation and propagation of electrical activity. Voltage-gated potassium channel subunit Kv3.3 is expressed in the distal dendrites of Purkinje cells. However, the functional relevance of this dendritic distribution is not understood. Moreover, mutations in Kv3.3 cause movement disorders in mice and cerebellar atrophy and ataxia in humans, emphasizing the importance of understanding the role of these channels. In this study, we explore functional implications of this dendritic channel expression and compare Purkinje cell dendritic excitability in wild-type and Kv3.3 knockout mice. We demonstrate enhanced excitability of Purkinje cell dendrites in Kv3.3 knockout mice, despite normal resting membrane properties. Combined data from local application pharmacology, voltage clamp analysis of ionic currents, and assessment of dendritic Ca(2+) spike threshold in Purkinje cells suggest a role for Kv3.3 channels in opposing Ca(2+) spike initiation. To study the physiological relevance of altered dendritic excitability, we measured [Ca(2+)](i) changes throughout the dendritic tree in response to climbing fiber activation. Ca(2+) signals were specifically enhanced in distal dendrites of Kv3.3 knockout Purkinje cells, suggesting a role for dendritic Kv3.3 channels in regulating propagation of electrical activity and Ca(2+) influx in distal dendrites. These findings characterize unique roles of Kv3.3 channels in dendrites, with implications for synaptic integration, plasticity, and human disease.

  10. Molecular Characterization of Dendritic Cell-Derived Exosomes

    OpenAIRE

    Théry, Clotilde; Regnault, Armelle; Garin, Jérôme; Wolfers, Joseph; Zitvogel, Laurence; Ricciardi-Castagnoli, Paola; Raposo, Graça; Amigorena, Sebastian

    1999-01-01

    Exosomes are membrane vesicles secreted by hematopoietic cells upon fusion of late multivesicular endosomes with the plasma membrane. Dendritic cell (DC)-derived exosomes induce potent antitumor immune responses in mice, resulting in the regression of established tumors (Zitvogel, L., A. Regnault, A. Lozier, J. Wolfers, C. Flament, D. Tenza, P. Ricciardi-Castagnoli, G. Raposo, and S. Amigorena. 1998. Nat. Med. 4:594–600). To unravel the molecular basis of exosome-induced immune stimulation, w...

  11. Modulation of respiratory dendritic cells during Klebsiella pneumonia infection

    OpenAIRE

    Hackstein, Holger; Kranz, Sabine; Lippitsch, Anne; Wachtendorf, Andreas; Kershaw, Olivia; Achim D Gruber; Michel, Gabriela; Lohmeyer, Jürgen; Bein, Gregor; Baal, Nelli; Herold, Susanne

    2013-01-01

    Background: Klebsiella pneumoniae is a leading cause of severe hospital-acquired respiratory tract infections and death but little is known regarding the modulation of respiratory dendritic cell (DC) subsets. Plasmacytoid DC (pDC) are specialized type 1 interferon producing cells and considered to be classical mediators of antiviral immunity. Method: By using multiparameter flow cytometry analysis we have analysed the modulation of respiratory DC subsets after intratracheal Klebsi...

  12. The role of the vascular dendritic cell network in atherosclerosis

    OpenAIRE

    Alberts-Grill, Noah; Denning, Timothy L.; Rezvan, Amir; Jo, Hanjoong

    2013-01-01

    A complex role has been described for dendritic cells (DCs) in the potentiation and control of vascular inflammation and atherosclerosis. Resident vascular DCs are found in the intima of atherosclerosis-prone vascular regions exposed to disturbed blood flow patterns. Several phenotypically and functionally distinct vascular DC subsets have been described. The functional heterogeneity of these cells and their contributions to vascular homeostasis, inflammation, and atherosclerosis are only rec...

  13. Dendritic Cells for Real-Time Anomaly Detection

    CERN Document Server

    Greensmith, Julie

    2010-01-01

    Dendritic Cells (DCs) are innate immune system cells which have the power to activate or suppress the immune system. The behaviour of human of human DCs is abstracted to form an algorithm suitable for anomaly detection. We test this algorithm on the real-time problem of port scan detection. Our results show a significant difference in artificial DC behaviour for an outgoing portscan when compared to behaviour for normal processes.

  14. Cigarette smoke promotes dendritic cell accumulation in COPD; a Lung Tissue Research Consortium study

    Directory of Open Access Journals (Sweden)

    Yi Eunhee S

    2010-04-01

    Full Text Available Abstract Background Abnormal immune responses are believed to be highly relevant in the pathogenesis of chronic obstructive pulmonary disease (COPD. Dendritic cells provide a critical checkpoint for immunity by their capacity to both induce and suppress immunity. Although evident that cigarette smoke, the primary cause of COPD, significantly influences dendritic cell functions, little is known about the roles of dendritic cells in the pathogenesis of COPD. Methods The extent of dendritic cell infiltration in COPD tissue specimens was determined using immunohistochemical localization of CD83+ cells (marker of matured myeloid dendritic cells, and CD1a+ cells (Langerhans cells. The extent of tissue infiltration with Langerhans cells was also determined by the relative expression of the CD207 gene in COPD versus control tissues. To determine mechanisms by which dendritic cells accumulate in COPD, complimentary studies were conducted using monocyte-derived human dendritic cells exposed to cigarette smoke extract (CSE, and dendritic cells extracted from mice chronically exposed to cigarette smoke. Results In human COPD lung tissue, we detected a significant increase in the total number of CD83+ cells, and significantly higher amounts of CD207 mRNA when compared with control tissue. Human monocyte-derived dendritic cells exposed to CSE (0.1-2% exhibited enhanced survival in vitro when compared with control dendritic cells. Murine dendritic cells extracted from mice exposed to cigarette smoke for 4 weeks, also demonstrated enhanced survival compared to dendritic cells extracted from control mice. Acute exposure of human dendritic cells to CSE induced the cellular pro-survival proteins heme-oxygenase-1 (HO-1, and B cell lymphoma leukemia-x(L (Bcl-xL, predominantly through oxidative stress. Although activated human dendritic cells conditioned with CSE expressed diminished migratory CCR7 expression, their migration towards the CCR7 ligand CCL21 was not

  15. CD1c+ blood dendritic cells have Langerhans cell potential.

    Science.gov (United States)

    Milne, Paul; Bigley, Venetia; Gunawan, Merry; Haniffa, Muzlifah; Collin, Matthew

    2015-01-15

    Langerhans cells (LCs) are self-renewing in the steady state but repopulated by myeloid precursors after injury. Human monocytes give rise to langerin-positive cells in vitro, suggesting a potential precursor role. However, differentiation experiments with human lineage-negative cells and CD34(+) progenitors suggest that there is an alternative monocyte-independent pathway of LC differentiation. Recent data in mice also show long-term repopulation of the LC compartment with alternative myeloid precursors. Here we show that, although monocytes are able to express langerin, when cultured with soluble ligands granulocyte macrophage colony-stimulating factor (GM-CSF), transforming growth factor β (TGFβ), and bone morphogenetic protein 7 (BMP7), CD1c(+) dendritic cells (DCs) become much more LC-like with high langerin, Birbeck granules, EpCAM, and E-cadherin expression under the same conditions. These data highlight a new potential precursor function of CD1c(+) DCs and demonstrate an alternative pathway of LC differentiation that may have relevance in vivo.

  16. Murine and Human Model Systems for the Study of Dendritic Cell Immunobiology.

    Science.gov (United States)

    Hargadon, Kristian M

    2016-01-01

    Dendritic cells are a population of innate immune cells that possess their own effector functions as well as numerous regulatory properties that shape the activity of other innate and adaptive cells of the immune system. Following their development from either lymphoid or myeloid progenitors, the function of dendritic cells is tightly linked to their maturation and activation status. Differentiation into specialized subsets of dendritic cells also contributes to the diverse immunologic functions of these cells. Because of the key role played by dendritic cells in the regulation of both immune tolerance and activation, significant efforts have been focused on understanding dendritic cell biology. This review highlights the model systems currently available to study dendritic cell immunobiology and emphasizes the advantages and disadvantages to each system in both murine and human settings. In particular, in vitro cell culture systems involving immortalized dendritic cell lines, ex vivo systems for differentiating and expanding dendritic cells from their precursor populations, and systems for expanding, ablating, and manipulating dendritic cells in vivo are discussed. Emphasis is placed on the contribution of these systems to our current understanding of the development, function, and immunotherapeutic applications of dendritic cells, and insights into how these models might be extended in the future to answer remaining questions in the field are discussed.

  17. Therapeutic dendritic-cell vaccine for simian AIDS

    Institute of Scientific and Technical Information of China (English)

    Lu,W; Wu,XX; Lu,YZ; Guo,WZ; Andrieu,JM

    2005-01-01

    An effective immune response against human immunodeficiency virus or simian immunodeficiency virus (SIV) is critical in achieving control of viral replication. Here, we show in SIV-infected rhesus monkeys that an effective and durable SIV-specific cellular and humoral immunity is elicited by a vaccination with chemically inactivated SIV-pulsed dendritic cells. After three immunizations made at two-week intervals, the animals exhibited a 50-fold decrease of SIV DNA and a 1,000-fold decrease of SIV RNA in peripheral blood. Such reduced viral load levels were maintained over the remaining 34 weeks of the study. Molecular and cellular analyses of axillary and inguinal node lymphocytes of vaccinated monkeys revealed a correlation between decreased SIV DNA and RNA levels and increased SIV-specific T-cell responses. Neutralizing antibody responses were augmented and remained elevated. Inactivated whole virus-pulsed dendritic cell vaccines are promising means to control diseases caused by immunodeficiency viruses.

  18. Differential expression of Toll-like receptors in dendritic cells of patients with dengue during early and late acute phases of the disease.

    Directory of Open Access Journals (Sweden)

    Silvia Torres

    Full Text Available BACKGROUND: Dengue hemorrhagic fever (DHF is observed in individuals that have pre-existing heterotypic dengue antibodies and is associated with increased viral load and high levels of pro-inflammatory cytokines early in infection. Interestingly, a recent study showed that dengue virus infection in the presence of antibodies resulted in poor stimulation of Toll-like receptors (TLRs, thereby facilitating virus particle production, and also suggesting that TLRs may contribute to disease pathogenesis. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the expression levels of TLR2, 3, 4 and 9 and the co-stimulatory molecules CD80 and CD86 by flow cytometry. This was evaluated in monocytes, in myeloid and plasmacytoid dendritic cells (mDCs and pDCs from 30 dengue patients with different clinical outcomes and in 20 healthy controls. Increased expression of TLR3 and TLR9 in DCs of patients with dengue fever (DF early in infection was detected. In DCs from patients with severe manifestations, poor stimulation of TLR3 and TLR9 was observed. In addition, we found a lower expression of TLR2 in patients with DF compared to DHF. Expression levels of TLR4 were not affected. Furthermore, the expression of CD80 and CD86 was altered in mDCs and CD86 in pDCs of severe dengue cases. We show that interferon alpha production decreased in the presence of dengue virus after stimulation of PBMCs with the TLR9 agonist (CpG A. This suggests that the virus can affect the interferon response through this signaling pathway. CONCLUSIONS/SIGNIFICANCE: These results show that during dengue disease progression, the expression profile of TLRs changes depending on the severity of the disease. Changes in TLRs expression could play a central role in DC activation, thereby influencing the innate immune response.

  19. The Current Immune Function of Hepatic Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Willy Hsu; Shang-An Shu; Eric Gershwin; Zhe-Xiong Lian

    2007-01-01

    While only a small percentage of the liver as dendritic cells, they play a major role in the regulation of liver immunity. Four major types of dendritic cell subsets include myeloid CD8α-B220-, lymphoid CD8α+B220-,plasmacytoid CD8α-B220+, and natural killer dendritic cell with CD8α-B220-NK1.1+ phenotype. Although these subsets have slightly different characteristics, they are all poor na(i)ve T cell stimulators. In exchange for their reduced capacity for allostimulation, hepatic DCs are equipped with an enhanced ability to secrete cytokines in response to TLR stimulation. In addition, they have increased level of phagocytosis. Both of these traits suggest hepatic DC as part of the innate immune system. With such a high rate of exposure to the dietary and commensal antigens, it is important for the hepatic DCs to have an enhanced innate response while maintaining a tolerogenic state to avoid chronic inflammation. Only upon secondary infectivity does the hepatic DC activate memory T cells for rapid eradication of recurring pathogen. On the other hand, overly tolerogenic characteristics of hepatic DC may be responsible for the increase prevalence of autoimmunity or liver malignancies.

  20. Evaluation of two different dendritic cell preparations with BCG reactivity

    Directory of Open Access Journals (Sweden)

    Fol Marek

    2016-01-01

    Full Text Available Dendritic cells (DCs play a key-role in the immune response against intracellular bacterial pathogens, including mycobacteria. Monocyte-derived dendritic cells (MoDCs are considered to behave as inflammatory cell populations. Different immunomagnetic methods (positive and negative can be used to purify monocytes before their in vitro differentiation and their culture behavior can be expected to be different. In this study we evaluated the reactivity of two dendritic cell populations towards the Bacillus Calmette-Guérin (BCG antigen. Monocytes were obtained from the blood of healthy donors, using positive and negative immunomagnetic separation methods. The expression of DC-SIGN, CD86, CD80, HLA-DR and CD40 on MoDCs was estimated by flow cytometry. The level of IL-12p70, IL-10 and TNF-α was measured by ELISA. Neither of the tested methods affected the surface marker expression of DCs. No significant alteration in immunological response, measured by cytokine production, was noted either. After BCG stimulation, the absence of IL-12, but the IL-23 production was observed in both cell preparations. Positive and negative magnetic separation methods are effective techniques to optimize the preparation of monocytes as the source of MoDCs for potential clinical application.

  1. Immunohistochemical patterns of follicular dendritic cell meshwork and Ki-67 in small B-cell lymphomas

    Institute of Scientific and Technical Information of China (English)

    时云飞

    2013-01-01

    Objective To identify the immunohistochemical patterns of follicular dendritic cell(FDC)meshwork and Ki-67labeling index in small B-cell lymphomas(SBLs) and their significance in differential diagnosis.Methods

  2. Novel murine dendritic cell lines: a powerful auxiliary tool for dendritic cell research

    Directory of Open Access Journals (Sweden)

    Silvia A Fuertes Marraco

    2012-11-01

    Full Text Available Research in vitro facilitates discovery, screening and pilot experiments, often preceding research in vivo. Several technical difficulties render Dendritic Cell (DC research particularly challenging, including the low frequency of DC in vivo, thorough isolation requirements, and the vulnerability of DC ex vivo. Critically, there is not as yet a widely accepted human or murine DC line and in vitro systems of DC research are limited. In this study, we report the generation of new murine DC lines, named MutuDC, originating from cultures of splenic CD8α conventional DC (cDC tumors. By direct comparison to normal WT splenic cDC subsets, we describe the phenotypic and functional features of the MutuDC lines and show that they have retained all the major features of their natural counterpart in vivo, the splenic CD8α cDC. These features include expression of surface markers Clec9A, DEC205, and CD24, positive response to TLR3 and TLR9 but not TLR7 stimuli, secretion of cytokines and chemokines upon activation, as well as cross-presentation capacity. In addition to the close resemblance to normal splenic CD8α cDC, a major advantage is the ease of derivation and maintenance of the MutuDC lines, using standard culture medium and conditions, importantly without adding supplementary growth factors or maturation-inducing stimuli to the medium. Furthermore, genetically modified MutuDC lines have been successfully obtained either by lentiviral transduction or by culture of DC tumors originating from genetically modified mice.In view of the current lack of stable and functional DC lines, these novel murine DC lines have the potential to serve as an important auxiliary tool for DC research.

  3. A general principle governs vision-dependent dendritic patterning of retinal ganglion cells.

    Science.gov (United States)

    Xu, Hong-Ping; Sun, Jin Hao; Tian, Ning

    2014-10-15

    Dendritic arbors of retinal ganglion cells (RGCs) collect information over a certain area of the visual scene. The coverage territory and the arbor density of dendrites determine what fraction of the visual field is sampled by a single cell and at what resolution. However, it is not clear whether visual stimulation is required for the establishment of branching patterns of RGCs, and whether a general principle directs the dendritic patterning of diverse RGCs. By analyzing the geometric structures of RGC dendrites, we found that dendritic arbors of RGCs underwent a substantial spatial rearrangement after eye-opening. Light deprivation blocked both the dendritic growth and the branch patterning, suggesting that visual stimulation is required for the acquisition of specific branching patterns of RGCs. We further showed that vision-dependent dendritic growth and arbor refinement occurred mainly in the middle portion of the dendritic tree. This nonproportional growth and selective refinement suggest that the late-stage dendritic development of RGCs is not a passive stretching with the growth of eyes, but rather an active process of selective growth/elimination of dendritic arbors of RGCs driven by visual activity. Finally, our data showed that there was a power law relationship between the coverage territory and dendritic arbor density of RGCs on a cell-by-cell basis. RGCs were systematically less dense when they cover larger territories regardless of their cell type, retinal location, or developmental stage. These results suggest that a general structural design principle directs the vision-dependent patterning of RGC dendrites.

  4. Large-Scale mRNA Transfection of Dendritic Cells by Electroporation in Continuous Flow Systems

    DEFF Research Database (Denmark)

    Selmeczi, Dávid; Hansen, Thomas Steen; Met, Özcan

    2016-01-01

    Electroporation is well established for transient mRNA transfection of many mammalian cells, including immune cells such as dendritic cells used in cancer immunotherapy. Therapeutic application requires methods to efficiently electroporate and transfect millions of immune cells in a fast process...... the instrumentation and methods needed for the efficient transfection by electroporation of millions of dendritic cells in one continuous flow process....... with high cell survival. Continuous flow of suspended dendritic cells through a channel incorporating spatially separated microporous meshes with a synchronized electrical pulsing sequence can yield dendritic cell transfection rates of >75 % with survival rates of >90 %. This chapter describes...

  5. The analysis of purkinje cell dendritic morphology in organotypic slice cultures.

    Science.gov (United States)

    Kapfhammer, Josef P; Gugger, Olivia S

    2012-03-21

    Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly oriented in the sagittal plane and develops mostly in the postnatal period in small rodents (3). Furthermore, several antibodies are available which selectively and intensively label Purkinje cells including all processes, with anti-Calbindin D28K being the most widely used. For viewing of dendrites in living cells, mice expressing EGFP selectively in Purkinje cells (11) are available through Jackson labs. Organotypic cerebellar slice cultures cells allow easy experimental manipulation of Purkinje cell dendritic development because most of the dendritic expansion of the Purkinje cell dendritic tree is actually taking place during the culture period (4). We present here a short, reliable and easy protocol for viewing and analyzing the dendritic morphology of Purkinje cells grown in organotypic cerebellar slice cultures. For many purposes, a quantitative evaluation of the Purkinje cell dendritic tree is desirable. We focus here on two parameters, dendritic tree size and branch point numbers, which can be rapidly and easily determined from anti-calbindin stained cerebellar slice cultures. These two parameters yield a reliable and sensitive measure of changes of the Purkinje cell dendritic tree. Using the example of treatments with the protein kinase C (PKC) activator PMA and the metabotropic glutamate receptor 1 (mGluR1) we demonstrate how differences in the dendritic development are visualized and quantitatively assessed. The combination of the presence of an extensive dendritic tree, selective and intense immunostaining methods, organotypic slice cultures which cover the period of dendritic growth and a mouse model with Purkinje cell specific EGFP expression make Purkinje cells a powerful model system for revealing the mechanisms of dendritic development.

  6. Dextromethorphan Inhibits Activations and Functions in Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Der-Yuan Chen

    2013-01-01

    Full Text Available Dendritic cells (DCs play an important role in connecting innate and adaptive immunity. Thus, DCs have been regarded as a major target for the development of immunomodulators. In this study, we examined the effect of dextromethorphan (DXM, a common cough suppressant with a high safety profile, on the activation and function of DCs. In the presence of DXM, the LPS-induced expression of the costimulatory molecules in murine bone marrow-derived dendritic cells (BMDCs was significantly suppressed. In addition, DXM treatment reduced the production of reactive oxygen species (ROS, proinflammatory cytokines, and chemokines in maturing BMDCs that were activated by LPS. Therefore, DXM abrogated the ability of LPS-stimulated DCs to induce Ag-specific T-cell activation, as determined by their decreased proliferation and IFN-γ secretion in mixed leukocyte cultures. Moreover, the inhibition of LPS-induced MAPK activation and NF-κB translocation may contribute to the suppressive effect of DXM on BMDCs. Remarkably, DXM decreased the LPS-induced surface expression of CD80, CD83, and HLA-DR and the secretion of IL-6 and IL-12 in human monocyte-derived dendritic cells (MDDCs. These findings provide a new insight into the impact of DXM treatment on DCs and suggest that DXM has the potential to be used in treating DC-related acute and chronic diseases.

  7. Dextromethorphan Inhibits Activations and Functions in Dendritic Cells

    Science.gov (United States)

    Chen, Der-Yuan; Song, Pei-Shan; Hong, Jau-Shyong; Chu, Ching-Liang; Pan, I-Horng; Chen, Yi-Ming; Lin, Ching-Hsiung; Lin, Sheng-Hao; Lin, Chi-Chen

    2013-01-01

    Dendritic cells (DCs) play an important role in connecting innate and adaptive immunity. Thus, DCs have been regarded as a major target for the development of immunomodulators. In this study, we examined the effect of dextromethorphan (DXM), a common cough suppressant with a high safety profile, on the activation and function of DCs. In the presence of DXM, the LPS-induced expression of the costimulatory molecules in murine bone marrow-derived dendritic cells (BMDCs) was significantly suppressed. In addition, DXM treatment reduced the production of reactive oxygen species (ROS), proinflammatory cytokines, and chemokines in maturing BMDCs that were activated by LPS. Therefore, DXM abrogated the ability of LPS-stimulated DCs to induce Ag-specific T-cell activation, as determined by their decreased proliferation and IFN-γ secretion in mixed leukocyte cultures. Moreover, the inhibition of LPS-induced MAPK activation and NF-κB translocation may contribute to the suppressive effect of DXM on BMDCs. Remarkably, DXM decreased the LPS-induced surface expression of CD80, CD83, and HLA-DR and the secretion of IL-6 and IL-12 in human monocyte-derived dendritic cells (MDDCs). These findings provide a new insight into the impact of DXM treatment on DCs and suggest that DXM has the potential to be used in treating DC-related acute and chronic diseases. PMID:23781253

  8. 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...

  9. Epidermal cells are the primary phagocytes in the fragmentation and clearance of degenerating dendrites in Drosophila.

    Science.gov (United States)

    Han, Chun; Song, Yuanquan; Xiao, Hui; Wang, Denan; Franc, Nathalie C; Jan, Lily Yeh; Jan, Yuh-Nung

    2014-02-05

    During developmental remodeling, neurites destined for pruning often degenerate on-site. Physical injury also induces degeneration of neurites distal to the injury site. Prompt clearance of degenerating neurites is important for maintaining tissue homeostasis and preventing inflammatory responses. Here we show that in both dendrite pruning and dendrite injury of Drosophila sensory neurons, epidermal cells rather than hemocytes are the primary phagocytes in clearing degenerating dendrites. Epidermal cells act via Draper-mediated recognition to facilitate dendrite degeneration and to engulf and degrade degenerating dendrites. Using multiple dendritic membrane markers to trace phagocytosis, we show that two members of the CD36 family, croquemort (crq) and debris buster (dsb), act at distinct stages of phagosome maturation for dendrite clearance. Our finding reveals the physiological importance of coordination between neurons and their surrounding epidermis, for both dendrite fragmentation and clearance.

  10. Comparison of runout range of PDCs in different density using Volcflow numerical simulation model

    Science.gov (United States)

    Chang, C.; Yun, S. H.

    2016-12-01

    In our preceding research, we simulated 45 scenarios using of a VolcFlow numerical simulation model to calculate runout range of pyroclastic density currents that caused by column collapse of the explosive Plinian eruption on the Mt. Baekdu, Korean peninsula (the border of North Korea and China). We assumed 2,000 kg/m3 for density of PDCs in previous scenarios. In this study, in order to find out the change of the runout range that according to different density, we refer to study of Rowley(2010), about the scale of density of PDCs that is 500- 3,000 kg/m3. So we set the density of the PDCs as 1,000 kg/m3, 2,000 kg/m3, 3,000 kg/m3, respectively under the same condition in previous study. Then we simulated total of 15 scenarios from VEI 3 to VEI 7 and compared to the results. In the results, the runout range of PDCs are increased a little in higher density. It seems that dense currents have high kinetic energy that makes the range of PDCs higher. But there are not a big differences in runout ranges even in case of VEI 7. Therefore, the density of PDCs does not have much effect on the runout range of PDCs. In this study we assumed the column collapse caused the PDCs, it needs further research in another type of PDCs that occurred by lava dome collapse.This research was supported by a grant [MPSS-NH-2015-81] through the Disaster and Safety Management Institute funded by Ministry of Public Safety and Security of Korean government.

  11. Viral piracy: HIV-1 targets dendritic cells for transmission.

    Science.gov (United States)

    Lekkerkerker, Annemarie N; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2006-04-01

    Dendritic cells (DCs), the professional antigen presenting cells, are critical for host immunity by inducing specific immune responses against a broad variety of pathogens. Remarkably the human immunodeficiency virus-1 (HIV-1) subverts DC function leading to spread of the virus. At an early phase of HIV-1 transmission, DCs capture HIV-1 at mucosal surfaces and transmit the virus to T cells in secondary lymphoid tissues. Capture of the virus on DCs takes place via C-type lectins of which the dendritic cell-specific intercellular adhesion molecule-3 (ICAM-3) grabbing nonintegrin (DC-SIGN) is the best studied. DC-SIGN-captured HIV-1 particles accumulate in CD81(+) multivesicular bodies (MVBs) in DCs and are subsequently transmitted to CD4+ T cells resulting in infection of T cells. The viral cell-to-cell transmission takes place at the DC-T cell interface termed the infectious synapse. Recent studies demonstrate that direct infection of DCs contributes to the transmission to T cells at a later phase. Moreover, the infected DCs may function as cellular reservoirs for HIV-1. This review discusses the different processes that govern viral piracy of DCs by HIV-1, emphasizing the intracellular routing of the virus from capture on the cell surface to egress in the infectious synapse.

  12. Colored visible light metamaterials based on random dendritic cells

    CERN Document Server

    Song, K; Liu, B Q; Zhao, X P

    2011-01-01

    Optical metamaterials(OMs) at visible wavelengths have been extensively developed. OMs reported presently are all composed of periodic structure, and fabricated by top-down approaches. Here, the colored visible light frequencies metamaterials composed of double layer array disordered and geometrical variational dendritic cells are demonstrated, fabricating by a novel bottom-up approach. The experiment demonstrated that the OMs composed of random silver dendritic cells caused the appearance of multiple transmission passbands at red and yellow light frequencies. The slab focusing experiment reveals a clear point image in the range of half-wavelength with an intensity of 5% higher than that of the light source. Proposed colored OMs will open a new way to prepare the cloak and the perfect lens suitable for optical frequency.

  13. Atypical protein kinase C regulates primary dendrite specification of cerebellar Purkinje cells by localizing Golgi apparatus.

    Science.gov (United States)

    Tanabe, Koji; Kani, Shuichi; Shimizu, Takashi; Bae, Young-Ki; Abe, Takaya; Hibi, Masahiko

    2010-12-15

    Neurons have highly polarized structures that determine what parts of the soma elaborate the axon and dendrites. However, little is known about the mechanisms that establish neuronal polarity in vivo. Cerebellar Purkinje cells extend a single primary dendrite from the soma that ramifies into a highly branched dendritic arbor. We used the zebrafish cerebellum to investigate the mechanisms by which Purkinje cells acquire these characteristics. To examine dendritic morphogenesis in individual Purkinje cells, we marked the cell membrane using a Purkinje cell-specific promoter to drive membrane-targeted fluorescent proteins. We found that zebrafish Purkinje cells initially extend multiple neurites from the soma and subsequently retract all but one, which becomes the primary dendrite. In addition, the Golgi apparatus specifically locates to the root of the primary dendrite, and its localization is already established in immature Purkinje cells that have multiple neurites. Inhibiting secretory trafficking through the Golgi apparatus reduces dendritic growth, suggesting that the Golgi apparatus is involved in the dendritic morphogenesis. We also demonstrated that in a mutant of an atypical protein kinase C (aPKC), Prkci, Purkinje cells retain multiple primary dendrites and show disrupted localization of the Golgi apparatus. Furthermore, a mosaic inhibition of Prkci in Purkinje cells recapitulates the aPKC mutant phenotype. These results suggest that the aPKC cell autonomously controls the Golgi localization and thereby regulates the specification of the primary dendrite of Purkinje cells.

  14. Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    L.D. Loopuijt

    2007-10-01

    Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

  15. Receptor-Dependent Coronavirus Infection of Dendritic Cells

    Science.gov (United States)

    Turner, Brian C.; Hemmila, Erin M.; Beauchemin, Nicole; Holmes, Kathryn V.

    2004-01-01

    In several mammalian species, including humans, coronavirus infection can modulate the host immune response. We show a potential role of dendritic cells (DC) in murine coronavirus-induced immune modulation and pathogenesis by demonstrating that the JAW SII DC line and primary DC from BALB/c mice and p/p mice with reduced expression of the murine coronavirus receptor, murine CEACAM1a, are susceptible to murine coronavirus infection by a receptor-dependent pathway. PMID:15113927

  16. Articulation and Clarification of the Dendritic Cell Algorithm

    CERN Document Server

    Greensmith, Julie; Twycross, Jamie

    2009-01-01

    The Dendritic Cell algorithm (DCA) is inspired by recent work in innate immunity. In this paper a formal description of the DCA is given. The DCA is described in detail, and its use as an anomaly detector is illustrated within the context of computer security. A port scan detection task is performed to substantiate the influence of signal selection on the behaviour of the algorithm. Experimental results provide a comparison of differing input signal mappings.

  17. Molecular signatures of maturing dendritic cells: implications for testing the quality of dendritic cell therapies

    Directory of Open Access Journals (Sweden)

    Wang Ena

    2010-01-01

    Full Text Available Abstract Background Dendritic cells (DCs are often produced by granulocyte-macrophage colony-stimulating factor (GM-CSF and interleukin-4 (IL-4 stimulation of monocytes. To improve the effectiveness of DC adoptive immune cancer therapy, many different agents have been used to mature DCs. We analyzed the kinetics of DC maturation by lipopolysaccharide (LPS and interferon-γ (IFN-γ induction in order to characterize the usefulness of mature DCs (mDCs for immune therapy and to identify biomarkers for assessing the quality of mDCs. Methods Peripheral blood mononuclear cells were collected from 6 healthy subjects by apheresis, monocytes were isolated by elutriation, and immature DCs (iDCs were produced by 3 days of culture with GM-CSF and IL-4. The iDCs were sampled after 4, 8 and 24 hours in culture with LPS and IFN-γ and were then assessed by flow cytometry, ELISA, and global gene and microRNA (miRNA expression analysis. Results After 24 hours of LPS and IFN-γ stimulation, DC surface expression of CD80, CD83, CD86, and HLA Class II antigens were up-regulated. Th1 attractant genes such as CXCL9, CXCL10, CXCL11 and CCL5 were up-regulated during maturation but not Treg attractants such as CCL22 and CXCL12. The expression of classical mDC biomarker genes CD83, CCR7, CCL5, CCL8, SOD2, MT2A, OASL, GBP1 and HES4 were up-regulated throughout maturation while MTIB, MTIE, MTIG, MTIH, GADD45A and LAMP3 were only up-regulated late in maturation. The expression of miR-155 was up-regulated 8-fold in mDCs. Conclusion DCs, matured with LPS and IFN-γ, were characterized by increased levels of Th1 attractants as opposed to Treg attractants and may be particularly effective for adoptive immune cancer therapy.

  18. Induction and identification of rabbit peripheral blood derived dendritic cells

    Science.gov (United States)

    Zhou, Jing; Yang, FuYuan; Chen, WenLi

    2012-03-01

    Purpose: To study a method of the induction of dendritic cells (DCs) from rabbit peripheral blood. Methods: Peripheral blood cells were removed from rabbit, filtered through nylon mesh. Peripheral blood mononuclear cells (PBMC) were isolated from the blood cells by Ficoll-Hypaque centrifugation (density of 1.077g/cm3).To obtain DCs, PBMC were cultured in RPMI1640 medium containing 10% fetal calf serum, 50U/mL penicillin and streptomycin, referred to subsequently as complete medium, at 37°C in 5% CO2 atmosphere for 4 hours. Nonadherent cells were aspirated, adherent cells were continued incubated in complete medium, supplemented with granulocyte/macrophage colony-stimulating factor (GM-CSF, 50ng/ml),and interleukin 4 (IL-4, 50ng/ml) for 9 days. Fluorescein labeled antibodies(anti-CD14, anti-HLA-DR, anti-CD86) were used to sign cells cultured for 3,6,9 days respectively, Then flow cytometry was performed. Results: Ratio of anti-HLA-DR and anti-CD86 labeled cells increased with induction time extension, in contrast with anti-CD14. Conclusion: Dendritic cells can be effectively induced by the method of this experiment, cell maturation status increased with induction time extension.

  19. Molecular programming of steady-state dendritic cells: impact on autoimmunity and tumor immune surveillance.

    Science.gov (United States)

    Johnson, Dylan J; Ohashi, Pamela S

    2013-05-01

    Dendritic cells are master regulators of immunity. Immature dendritic cells are essential for maintaining self-tolerance, while mature dendritic cells initiate a variety of specialized immune responses. Dendritic cell quiescence is often viewed as a default state that requires exogenous stimuli to induce maturation. However, recent studies have identified dendritic cell quiescence factors that actively program dendritic cells to an immature state. In the absence of these factors, dendritic cells spontaneously become immunogenic and can induce autoimmune responses. Herein we discuss two such factors, NF-κB1 and A20, that preserve dendritic cell immaturity through their regulation of NF-κB signaling. Loss of either of these factors increases dendritic cell immunogenicity, suggesting that they may be important targets for enhancing dendritic cell-based cancer immunotherapies. Alternatively, defects in molecules critical for maintaining steady-state DCs may provide novel biomarkers that identify patients who have enhanced natural antitumor immunity or that correlate with better responses to various immunotherapies.

  20. Dynamic Range of Vertebrate Retina Ganglion Cells: Importance of Active Dendrites and Coupling by Electrical Synapses

    Science.gov (United States)

    Publio, Rodrigo; Ceballos, Cesar Celis; Roque, Antonio C.

    2012-01-01

    The vertebrate retina has a very high dynamic range. This is due to the concerted action of its diverse cell types. Ganglion cells, which are the output cells of the retina, have to preserve this high dynamic range to convey it to higher brain areas. Experimental evidence shows that the firing response of ganglion cells is strongly correlated with their total dendritic area and only weakly correlated with their dendritic branching complexity. On the other hand, theoretical studies with simple neuron models claim that active and large dendritic trees enhance the dynamic range of single neurons. Theoretical models also claim that electrical coupling between ganglion cells via gap junctions enhances their collective dynamic range. In this work we use morphologically reconstructed multi-compartmental ganglion cell models to perform two studies. In the first study we investigate the relationship between single ganglion cell dynamic range and number of dendritic branches/total dendritic area for both active and passive dendrites. Our results support the claim that large and active dendrites enhance the dynamic range of a single ganglion cell and show that total dendritic area has stronger correlation with dynamic range than with number of dendritic branches. In the second study we investigate the dynamic range of a square array of ganglion cells with passive or active dendritic trees coupled with each other via dendrodendritic gap junctions. Our results suggest that electrical coupling between active dendritic trees enhances the dynamic range of the ganglion cell array in comparison with both the uncoupled case and the coupled case with cells with passive dendrites. The results from our detailed computational modeling studies suggest that the key properties of the ganglion cells that endow them with a large dynamic range are large and active dendritic trees and electrical coupling via gap junctions. PMID:23144767

  1. Dynamic range of vertebrate retina ganglion cells: importance of active dendrites and coupling by electrical synapses.

    Science.gov (United States)

    Publio, Rodrigo; Ceballos, Cesar Celis; Roque, Antonio C

    2012-01-01

    The vertebrate retina has a very high dynamic range. This is due to the concerted action of its diverse cell types. Ganglion cells, which are the output cells of the retina, have to preserve this high dynamic range to convey it to higher brain areas. Experimental evidence shows that the firing response of ganglion cells is strongly correlated with their total dendritic area and only weakly correlated with their dendritic branching complexity. On the other hand, theoretical studies with simple neuron models claim that active and large dendritic trees enhance the dynamic range of single neurons. Theoretical models also claim that electrical coupling between ganglion cells via gap junctions enhances their collective dynamic range. In this work we use morphologically reconstructed multi-compartmental ganglion cell models to perform two studies. In the first study we investigate the relationship between single ganglion cell dynamic range and number of dendritic branches/total dendritic area for both active and passive dendrites. Our results support the claim that large and active dendrites enhance the dynamic range of a single ganglion cell and show that total dendritic area has stronger correlation with dynamic range than with number of dendritic branches. In the second study we investigate the dynamic range of a square array of ganglion cells with passive or active dendritic trees coupled with each other via dendrodendritic gap junctions. Our results suggest that electrical coupling between active dendritic trees enhances the dynamic range of the ganglion cell array in comparison with both the uncoupled case and the coupled case with cells with passive dendrites. The results from our detailed computational modeling studies suggest that the key properties of the ganglion cells that endow them with a large dynamic range are large and active dendritic trees and electrical coupling via gap junctions.

  2. Suppressing The Growth Of Dendrites In Secondary Li Cells

    Science.gov (United States)

    Davies, Evan D.; Perrone, David E.; Shen, David H.

    1996-01-01

    Proposed technique for suppressing growth of lithium dendrites in rechargeable lithium electrochemical power cells involves periodic interruption of steady charging current with short, high-current discharge pulses. Technique applicable to lithium cells of several different types, including Li/TiS(2), Li/NbSe(3), Li/CoO(2), Li/MoS(2), Li/Vo(x), and Li/MnO(2). Cells candidates for use in spacecraft, military, communications, automotive, and other applications in which high-energy-density rechargeable batteries needed.

  3. Dendritic cell-development in steady-state and inflammation

    OpenAIRE

    Schmid, Michael Alexander

    2010-01-01

    Dendritic cells (DC), the major antigen-presenting cells, continuously need to be regenerated from bone marrow (BM) hematopoietic stem and progenitor cells (HSPC). What intermediate progenitors exist on the way to DC generation and what external factors act on these in steady-state and during inflammation, has not been addressed in detail. Flt3L is a non-redundant cytokine in DC development and the generation of DCs was shown to proceed along both Flt3+ common lymphoid and common myeloid prog...

  4. Lipid-laden dendritic cells fail to function

    Institute of Scientific and Technical Information of China (English)

    Philip C Calder

    2010-01-01

    @@ Dendritic cells(DCs)are professional antigen-acquiring,-processing and-presenting cells[1-4].As such,DCs form the key link between the innate and acquired immune responses playing a role in host defence and in immune tolerance[1-4].Accordingly,defects in the ability of DCs to function can lead to increased susceptibility to infection,loss of tolerance,autoimmunity and tumour growth[1-4].Sub-classes of DCs are defined and discriminated by the expression of different cell surface markers.

  5. 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.

  6. EBI2 augments Tfh cell fate by promoting interaction with IL-2-quenching dendritic cells.

    Science.gov (United States)

    Li, Jianhua; Lu, Erick; Yi, Tangsheng; Cyster, Jason G

    2016-05-05

    T follicular helper (Tfh) cells are a subset of T cells carrying the CD4 antigen; they are important in supporting plasma cell and germinal centre responses. The initial induction of Tfh cell properties occurs within the first few days after activation by antigen recognition on dendritic cells, although how dendritic cells promote this cell-fate decision is not fully understood. Moreover, although Tfh cells are uniquely defined by expression of the follicle-homing receptor CXCR5 (refs 1, 2), the guidance receptor promoting the earlier localization of activated T cells at the interface of the B-cell follicle and T zone has been unclear. Here we show that the G-protein-coupled receptor EBI2 (GPR183) and its ligand 7α,25-dihydroxycholesterol mediate positioning of activated CD4 T cells at the interface of the follicle and T zone. In this location they interact with activated dendritic cells and are exposed to Tfh-cell-promoting inducible co-stimulator (ICOS) ligand. Interleukin-2 (IL-2) is a cytokine that has multiple influences on T-cell fate, including negative regulation of Tfh cell differentiation. We demonstrate that activated dendritic cells in the outer T zone further augment Tfh cell differentiation by producing membrane and soluble forms of CD25, the IL-2 receptor α-chain, and quenching T-cell-derived IL-2. Mice lacking EBI2 in T cells or CD25 in dendritic cells have reduced Tfh cells and mount defective T-cell-dependent plasma cell and germinal centre responses. These findings demonstrate that distinct niches within the lymphoid organ T zone support distinct cell fate decisions, and they establish a function for dendritic-cell-derived CD25 in controlling IL-2 availability and T-cell differentiation.

  7. Chlamydia pneumoniae infection induced allergic airway sensitization is controlled by regulatory T-cells and plasmacytoid dendritic cells.

    Directory of Open Access Journals (Sweden)

    Timothy R Crother

    Full Text Available Chlamydia pneumoniae (CP is associated with induction and exacerbation of asthma. CP infection can induce allergic airway sensitization in mice in a dose- and time-dependent manner. Allergen exposure 5 days after a low dose (mild-moderate, but not a high dose (severe CP infection induces antigen sensitization in mice. Innate immune signals play a critical role in controlling CP infection induced allergic airway sensitization, however these mechanisms have not been fully elucidated. Wild-type, TLR2-/-, and TLR4-/- mice were infected intranasally (i.n. with a low dose of CP, followed by i.n. exposure to human serum albumin (HSA and challenged with HSA 2 weeks later. Airway inflammation, immunoglobulins, eosinophils, and goblet cells were measured. Low dose CP infection induced allergic sensitization in TLR2-/- mice, but not in TLR4-/- mice, due to differential Treg responses in these genotypes. TLR2-/- mice had reduced numbers of Tregs in the lung during CP infection while TLR4-/- mice had increased numbers. High dose CP infection resulted in an increase in Tregs and pDCs in lungs, which prevented antigen sensitization in WT mice. Depletion of Tregs or pDCs resulted in allergic airway sensitization. We conclude that Tregs and pDCs are critical determinants regulating CP infection-induced allergic sensitization. Furthermore, TLR2 and TLR4 signaling during CP infection may play a regulatory role through the modulation of Tregs.

  8. Chlamydia pneumoniae infection induced allergic airway sensitization is controlled by regulatory T-cells and plasmacytoid dendritic cells.

    Science.gov (United States)

    Crother, Timothy R; Schröder, Nicolas W J; Karlin, Justin; Chen, Shuang; Shimada, Kenichi; Slepenkin, Anatoly; Alsabeh, Randa; Peterson, Ellena; Arditi, Moshe

    2011-01-01

    Chlamydia pneumoniae (CP) is associated with induction and exacerbation of asthma. CP infection can induce allergic airway sensitization in mice in a dose- and time-dependent manner. Allergen exposure 5 days after a low dose (mild-moderate), but not a high dose (severe) CP infection induces antigen sensitization in mice. Innate immune signals play a critical role in controlling CP infection induced allergic airway sensitization, however these mechanisms have not been fully elucidated. Wild-type, TLR2-/-, and TLR4-/- mice were infected intranasally (i.n.) with a low dose of CP, followed by i.n. exposure to human serum albumin (HSA) and challenged with HSA 2 weeks later. Airway inflammation, immunoglobulins, eosinophils, and goblet cells were measured. Low dose CP infection induced allergic sensitization in TLR2-/- mice, but not in TLR4-/- mice, due to differential Treg responses in these genotypes. TLR2-/- mice had reduced numbers of Tregs in the lung during CP infection while TLR4-/- mice had increased numbers. High dose CP infection resulted in an increase in Tregs and pDCs in lungs, which prevented antigen sensitization in WT mice. Depletion of Tregs or pDCs resulted in allergic airway sensitization. We conclude that Tregs and pDCs are critical determinants regulating CP infection-induced allergic sensitization. Furthermore, TLR2 and TLR4 signaling during CP infection may play a regulatory role through the modulation of Tregs.

  9. Inducing Maturation of Monocyte-Derived Dendritic Cells on Human Epithelial Cell Feeder Layer

    Directory of Open Access Journals (Sweden)

    Delirezh N

    2012-02-01

    Full Text Available Background: Nowadays, dendritic cells (DCs have a special place in cancer treatment strategies and they have been used for tumor immunotherapy as they can induce immune response against tumor cells. Researchers have been trying to generate efficient dendritic cells in vitro; therefore, this research was done to generate them for use in research and tumor immunotherapy. Methods: This study took place at Urmia University in 2010-2011 years. In this study plastic adherent monocytes were incubated with granulocyte-macrophage colony stimulating factor (GM-CSF and interleukin-4 (IL-4 for five days. Finally, fully matured and stable DCs were generated by 48 hours of incubation in a monocyte conditioned medium (MCM containing tumor necrosis factor-α (TNF-α and epithelial cells. Phenotypic and functional analysis were carried out by using anti-CD14, anti-CD80, anti-CD86, and anti-CD83 monoclonal antibodies, and by determining their phagocytic activity, mixed lymphocyte reaction (MLR and cytokine production, respectively. Results: Dendritic cells were produced with high levels of surface molecule, i.e. of CD80, CD83, CD86, HLA-DR, expression and low levels of CD14 expression. Dendritic cells showed efficient phagocytosis and ability to stimulate T-lymphocytes. Moreover, dendritic cells could secrete high levels of interleukin-12 (IL-12 cytokine which was depictive of their full maturation. Measurement of the produced cytokines showed the generation of type-1 dendritic cells (DC1. Conclusion: Our study showed that skin epithelial cells could induce maturation of monocyte-derived dendritic cells (DCs. This feeder layer led to the production of efficient dendritic cells with the ability to be used for tumor immunotherapy.

  10. 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

  11. Hepatitis B virus-like particles access major histocompatibility class I and II antigen presentation pathways in primary dendritic cells.

    Science.gov (United States)

    Moffat, Jessica M; Cheong, Wan-Shoo; Villadangos, José A; Mintern, Justine D; Netter, Hans J

    2013-04-26

    Virus-like particles (VLPs) represent high density displays of viral proteins that efficiently trigger immunity. VLPs composed of the small hepatitis B virus envelope protein (HBsAgS) are useful vaccine platforms that induce humoral and cellular immune responses. Notably, however, some studies suggest HBsAgS VLPs impair dendritic cell (DC) function. Here we investigated HBsAgS VLP interaction with DC subsets and antigen access to major histocompatibility complex (MHC) class I and II antigen presentation pathways in primary DCs. HBsAgS VLPs impaired plasmacytoid DC (pDC) interferon alpha (IFNα) production in response to CpG in vitro, but did not alter conventional DC (cDC) or pDC phenotype when administered in vivo. To assess cellular immune responses, HBsAgS VLPs were generated containing the ovalbumin (OVA) model epitopes OVA(257-264) and OVA(323-339) to access MHCI and MHCII antigen presentation pathways, respectively; both in vitro and following immunisation in vivo. HBsAgS VLP-OVA(257-264) elicited CTL responses in vivo that were not enhanced by inclusion of an additional MHCII helper epitope. HBsAgS VLP-OVA(257-264) administered in vivo was cross-presented by CD8(+) DCs, but not CD8(-) DCs. Therefore, HBsAgS VLPs can deliver antigen to both MHCI and MHCII antigen presentation pathways in primary DCs and promote cytotoxic and helper T cell priming despite their suppressive effect on pDCs.

  12. Generation of Th17 cells in response to intranasal infection requires TGF-β1 from dendritic cells and IL-6 from CD301b+ dendritic cells.

    Science.gov (United States)

    Linehan, Jonathan L; Dileepan, Thamotharampillai; Kashem, Sakeen W; Kaplan, Daniel H; Cleary, Patrick; Jenkins, Marc K

    2015-10-13

    Intranasal (i.n.) infections preferentially generate Th17 cells. We explored the basis for this anatomic preference by tracking polyclonal CD4(+) T cells specific for an MHC class II-bound peptide from the mucosal pathogen Streptococcus pyogenes. S. pyogenes MHC class II-bound peptide-specific CD4(+) T cells were first activated in the cervical lymph nodes following i.n. inoculation and then differentiated into Th17 cells. S. pyogenes-induced Th17 formation depended on TGF-β1 from dendritic cells and IL-6 from a CD301b(+) dendritic cell subset located in the cervical lymph nodes but not the spleen. Thus, the tendency of i.n. infection to induce Th17 cells is related to cytokine production by specialized dendritic cells that drain this site.

  13. Unique immunomodulatory effects of azelastine on dendritic cells in vitro.

    Science.gov (United States)

    Schumacher, S; Kietzmann, M; Stark, H; Bäumer, W

    2014-11-01

    Allergic contact dermatitis and atopic dermatitis are among the most common inflammatory skin diseases in western countries, and antigen-presenting cells like dendritic cells (DC) are key players in their pathophysiology. Histamine, an important mediator of allergic reactions, influences DC maturation and cytokine secretion, which led us to investigate the immunomodulatory potential of the well-known histamine H1 receptor antagonists: azelastine, olopatadine, cetirizine, and pyrilamine. Unlike other H1 antihistamines, azelastine decreased lipopolysaccharide-induced tumor necrosis factor α and interleukin-12 secretion from murine bone marrow-derived DC. This effect was independent of histamine receptors H1, H2, or H4 and may be linked to inhibition of the nuclear factor kappa B pathway. Moreover, only azelastine reduced proliferation of allogenic T cells in a mixed leukocyte reaction. We then tested topical application of the H1 antihistamines on mice sensitized against toluene-2,4-diisocyanate, a model of Th2-mediated allergic contact dermatitis. In contrast to the in vitro results, all investigated substances were efficacious in reducing allergic ear swelling. Azelastine has unique effects on dendritic cells and T cell interaction in vitro. However, this did not translate into superior in vivo efficacy for Th2-mediated allergic dermatitis, possibly due to the effects of the antihistamines on other cell types involved in skin inflammation. Future research will have to clarify whether these properties are relevant to in vivo models of allergic inflammation with a different T cell polarization.

  14. Dendritic cell podosome dynamics does not depend on the F-actin regulator SWAP-70.

    Directory of Open Access Journals (Sweden)

    Anne Götz

    Full Text Available In addition to classical adhesion structures like filopodia or focal adhesions, dendritic cells similar to macrophages and osteoclasts assemble highly dynamic F-actin structures called podosomes. They are involved in cellular processes such as extracellular matrix degradation, bone resorption by osteoclasts, and trans-cellular diapedesis of lymphocytes. Besides adhesion and migration, podosomes enable dendritic cells to degrade connective tissue by matrix metalloproteinases. SWAP-70 interacts with RhoGTPases and F-actin and regulates migration of dendritic cells. SWAP-70 deficient osteoclasts are impaired in F-actin-ring formation and bone resorption. In the present study, we demonstrate that SWAP-70 is not required for podosome formation and F-actin turnover in dendritic cells. Furthermore, we found that toll-like receptor 4 ligand induced podosome disassembly and podosome-mediated matrix degradation is not affected by SWAP-70 in dendritic cells. Thus, podosome formation and function in dendritic cells is independent of SWAP-70.

  15. 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.

  16. Methamphetamine Enhances HIV-1 Infectivity in Monocyte Derived Dendritic Cells

    OpenAIRE

    2008-01-01

    The US is currently experiencing an epidemic of methamphetamine (Meth) use as a recreational drug. Recent studies also show a high prevalence of HIV-1 infection among Meth users. We report that Meth enhances HIV-1 infectivity of dendritic cells as measured by multinuclear activation of a galactosidase indicator (MAGI) cell assay, p24 assay, and LTR-RU5 amplification. Meth induces increased HIV-1 infection in association with an increase in the HIV-1 coreceptors, CXCR4 and CCR5, and infection ...

  17. Self-antigen presentation by dendritic cells in autoimmunity

    Directory of Open Access Journals (Sweden)

    Ann-Katrin eHopp

    2014-02-01

    Full Text Available The operation of both central and peripheral tolerance ensures the prevention of autoimmune diseases. The maintenance of peripheral tolerance requires self-antigen presentation by professional antigen presenting cells (APCs. Dendritic cells (DCs are considered as major APCs involved in this process. The current review discusses the role of DCs in autoimmune diseases, the various factors involved in the induction and maintenance of tolerogenic DC phenotype and pinpoints their therapeutic capacity as well as potential novel targets for future clinical studies.

  18. SUBTYPE CHARACTERICS OF DENDRITIC CELLS FROM PERIPHERAL BLOOD OF PATIENTS WITH RHEUMATOID ARTHRITIS

    Directory of Open Access Journals (Sweden)

    S. A. Falaleeva

    2013-01-01

    Full Text Available Abstract. Characteristics of myeloid and plasmacytoid dendritic cells from peripheral blood were studied in healthy donors and patients with rheumatoid arthritis (RA. We evaluated relative amounts of dendritic cell by their subtypes, degree of their maturity, and ability to respond to the maturation factors (toll-like receptor 4, 7 and 8 agonists. The results of in vitro experiments have shown that the patients with rheumatoid arthritis exhibited a significant reduction in numbers of plasmacytoid dendritic cells from peripheral blood. A sufficient decrease in CD83, CD80 expression on dendritic cell subtypes in RA patients was significantly less, than in healthy donors. In patients with RA, a significant increase in the number of CCR7-expressing plasmacytoid dendritic cells was shown in peripheral blood. In stimulated cultures, maturation of dendritic cells expressing maturation markers (CD83, CD80, CCR7 proved to be increased up to normal values. It should be noted that the counts of plasmacytoid dendritic cells in peripheral blood of RA patients expressing CCR7 was significantly higher than among healthy donors. Meanwhile, expression of CD83 and CD80 increased tovalues of healthy donors.Hence, we have found a significant reduction in relative counts of blood-derived myeloid and plasmacytoid dendritic cells expressing markers of mature dendritic cells (CD83, CD80 in patients with rheumatoid arthritis. Upon stimulated in vitro maturation, the counts of myeloid and plasmacytoid dendritic cells expressing CD83 and CD80 increased to the values corresponding to those of control group. RA patients showed significantly higher numbers of plasmacytoid dendritic cells expressing CCR7. This could indicate some changes in functional activity of dendritic cells in peripheral blood of patients with RA.

  19. The Analysis of Purkinje Cell Dendritic Morphology in Organotypic Slice Cultures

    OpenAIRE

    Kapfhammer, Josef P.; Gugger, Olivia S.

    2012-01-01

    Purkinje cells are an attractive model system for studying dendritic development, because they have an impressive dendritic tree which is strictly oriented in the sagittal plane and develops mostly in the postnatal period in small rodents 3. Furthermore, several antibodies are available which selectively and intensively label Purkinje cells including all processes, with anti-Calbindin D28K being the most widely used. For viewing of dendrites in living cells, mice expressing EGFP selectively i...

  20. The serotonin receptor 5-HT₇R regulates the morphology and migratory properties of dendritic cells.

    Science.gov (United States)

    Holst, Katrin; Guseva, Daria; Schindler, Susann; Sixt, Michael; Braun, Armin; Chopra, Himpriya; Pabst, Oliver; Ponimaskin, Evgeni

    2015-08-01

    Dendritic cells are potent antigen-presenting cells endowed with the unique ability to initiate adaptive immune responses upon inflammation. Inflammatory processes are often associated with an increased production of serotonin, which operates by activating specific receptors. However, the functional role of serotonin receptors in regulation of dendritic cell functions is poorly understood. Here, we demonstrate that expression of serotonin receptor 5-HT7 (5-HT7R) as well as its downstream effector Cdc42 is upregulated in dendritic cells upon maturation. Although dendritic cell maturation was independent of 5-HT7R, receptor stimulation affected dendritic cell morphology through Cdc42-mediated signaling. In addition, basal activity of 5-HT7R was required for the proper expression of the chemokine receptor CCR7, which is a key factor that controls dendritic cell migration. Consistent with this, we observed that 5-HT7R enhances chemotactic motility of dendritic cells in vitro by modulating their directionality and migration velocity. Accordingly, migration of dendritic cells in murine colon explants was abolished after pharmacological receptor inhibition. Our results indicate that there is a crucial role for 5-HT7R-Cdc42-mediated signaling in the regulation of dendritic cell morphology and motility, suggesting that 5-HT7R could be a new target for treatment of a variety of inflammatory and immune disorders.

  1. Multiple modes of action potential initiation and propagation in mitral cell primary dendrite

    DEFF Research Database (Denmark)

    Chen, Wei R; Shen, Gongyu Y; Shepherd, Gordon M

    2002-01-01

    The mitral cell primary dendrite plays an important role in transmitting distal olfactory nerve input from olfactory glomerulus to the soma-axon initial segment. To understand how dendritic active properties are involved in this transmission, we have combined dual soma and dendritic patch...... recordings with computational modeling to analyze action-potential initiation and propagation in the primary dendrite. In response to depolarizing current injection or distal olfactory nerve input, fast Na(+) action potentials were recorded along the entire length of the primary dendritic trunk. With weak......-initiation site reflected an independent thresholding mechanism in the distal dendrite. When strong olfactory nerve excitation was paired with strong inhibition to the mitral cell basal secondary dendrites, a small fast prepotential was recorded at the soma, which indicated that an action potential was initiated...

  2. Dendritic Cell Cancer Vaccines: From the Bench to the Bedside

    Directory of Open Access Journals (Sweden)

    Tamar Katz

    2014-10-01

    Full Text Available The recognition that the development of cancer is associated with acquired immunodeficiency, mostly against cancer cells themselves, and understanding pathways inducing this immunosuppression, has led to a tremendous development of new immunological approaches, both vaccines and drugs, which overcome this inhibition. Both “passive” (e.g. strategies relying on the administration of specific T cells and “active” vaccines (e.g. peptide-directed or whole-cell vaccines have become attractive immunological approaches, inducing cell death by targeting tumor-associated antigens. Whereas peptide-targeted vaccines are usually directed against a single antigen, whole-cell vaccines (e.g. dendritic cell vaccines are aimed to induce robust responsiveness by targeting several tumor-related antigens simultaneously. The combination of vaccines with new immuno-stimulating agents which target “immunosuppressive checkpoints” (anti-CTLA-4, PD-1, etc. is likely to improve and maintain immune response induced by vaccination.

  3. Redefining the role of dendritic cells in periodontics.

    Science.gov (United States)

    Venkatesan, Gomathinayagam; Uppoor, Ashita; Naik, Dilip G

    2013-11-01

    A properly functioning adaptive immune system signifies the best features of life. It is diverse beyond compare, tolerant without fail, and capable of behaving appropriately with a myriad of infections and other challenges. Dendritic cells (DCs) are required to explain how this remarkable system is energized and directed. DCs consist of a family of antigen presenting cells, which are bone-marrow-derived cells that patrol all tissues of the body with the possible exceptions of the brain and testes. DCs function to capture bacteria and other pathogens for processing and presentation to T cells in the secondary lymphoid organs. They serve as an essential link between innate and adaptive immune systems and induce both primary and secondary immune responses. As a result of progress worldwide, there is now evidence of a central role for dendritic cells in initiating antigen-specific immunity and tolerance. This review addresses the origins and migration of DCs to target sites, their basic biology and plasticity in playing a key role in periodontal diseases, and finally, selected strategies being pursued to harness its ability to prevent periodontal diseases.

  4. Functional changes of dendritic cells in hypersensivity reactions to amoxicillin

    Directory of Open Access Journals (Sweden)

    C.M.F. Lima

    2010-10-01

    Full Text Available A better understanding of dendritic cell (DC involvement in responses to haptenic drugs is needed, because it represents a possible approach to the development of an in vitro test, which could identify patients prone to drug allergies. There are two main DC subsets: plasmacytoid DC (pDC and myeloid DC (mDC. β-lactams form hapten-carrier conjugates and may provide a suitable model to study DC behavior in drug allergy reactions. It has been demonstrated that drugs interact differently with DC in drug allergic and non-allergic patients, but there are no studies regarding these subsets. Our aim was to assess the functional changes of mDC and pDC harvested from an amoxicillin-hypersensitive 32-year-old woman who experienced a severe maculopapular exanthema as reflected in interleukin-6 (IL-6 production after stimulation with this drug and penicillin. We also aim to demonstrate, for the first time, the feasibility of this method for dendritic cell isolation followed by in vitro stimulation for studies of drug allergy physiopathology. DC were harvested using a double Percoll density gradient, which generates a basophil-depleted cell (BDC suspension. Further, pDC were isolated by blood DC antigen 4-positive magnetic selection and gravity filtration through magnetized columns. After stimulation with amoxicillin, penicillin and positive and negative controls, IL-6 production was measured by ELISA. A positive dose-response curve for IL-6 after stimulation with amoxicillin and penicillin was observed for pDC, but not for mDC or BDC suspension. These preliminary results demonstrate the feasibility of this methodology to expand the knowledge of the effect of dendritic cell activation by drug allergens.

  5. Allergen recognition by innate immune cells: critical role of dendritic and epithelial cells

    Directory of Open Access Journals (Sweden)

    Fabian eSalazar

    2013-11-01

    Full Text Available Allergy is an exacerbated response of the immune system against non-self-proteins called allergens and is typically characterized by biased type-2 T helper cell and deleterious IgE mediated immune responses. The allergic cascade starts with the recognition of allergens by antigen presenting cells, mainly dendritic cells, culminating in mast cell sensitization and triggering. Dendritic cells have been demonstrated to play a crucial role in orchestrating allergic diseases. Using different C-type lectin receptors dendritic cells are able to recognize and internalize a number of allergens from diverse sources leading to sensitization. Furthermore, there is increasing evidence highlighting the role of epithelial cells in triggering and modulating immune responses to allergens. As well as providing a physical barrier, epithelial cells can interact with allergens and influence dendritic cells behaviour through the release of a number of Th2 promoting cytokines. In this review we will summarise current understanding of how allergens are recognised by dendritic cells and epithelial cells and what are the consequences of such interaction in the context of allergic sensitisation and downstream events leading to allergic inflammation. Better understanding of the molecular mechanisms of allergen recognition and associated signalling pathways could enable developing more effective therapeutic strategies that target the initial steps of allergic sensitisation hence hindering development or progression of allergic diseases.

  6. Regulatory T cells, dendritic cells and neutrophils in patients with renal cell carcinoma.

    Science.gov (United States)

    Minárik, Ivo; Lašťovička, Jan; Budinský, Vít; Kayserová, Jana; Spíšek, Radek; Jarolím, Ladislav; Fialová, Anna; Babjuk, Marek; Bartůňková, Jiřina

    2013-05-01

    We evaluated dendritic cells (DC), regulatory T lymphocytes (Treg) and neutrophils in 37 patients with newly diagnosed renal cell carcinoma (RCC) in the tumor and peripheral blood (PB) and correlated these parameters with tumor staging (early-T1, 2, late-T3, 4 and metastatic disease). The number of myeloid and plasmacytoid DC in blood of RCC patients was higher than in healthy controls. The percentage of myeloid dendritic cells (mDC) from CD45+ cells in tumors was higher in comparison with peripheral blood irrespective of disease stage. Higher percentage of these cells expressed a maturation marker in the periphery in the early stage (CD83 expressing cells). The number of plasmacytoid dendritic cells (pDC) in PB was similar in both early and late stage groups, but the early group displayed a significantly higher percentage of pDC in tumor cell suspension. Neutrophil counts in the peripheral blood of RCC patients were higher than in healthy controls, but the counts in both tumor stage groups were similar. The proportion of neutrophils from CD45+ cells was higher in late stage tumors. Higher percentage of Treg from CD4+ cells was detected in renal carcinoma tissue in comparison to PB with no difference between stages of the disease. Our results reflect the complex interplay between various cells of the immune system and the tumor microenvironment. Activation of dendritic cell subpopulations at early stages of the disease course is counterbalanced by the early appearance of T regulatory cells both in the periphery and tumor tissue. Later stages are characterized by the accumulation of neutrophils in the tumor. Appropriate timing of anticancer strategies, especially immunotherapy, should take these dynamics of the immune response in RCC patients into account.

  7. Investigating evolutionary conservation of dendritic cell subset identity and functions

    Directory of Open Access Journals (Sweden)

    Thien-Phong eVu Manh

    2015-06-01

    Full Text Available Dendritic cells (DC were initially defined as mononuclear phagocytes with a dendritic morphology and an exquisite efficiency for naïve T cell activation. DC encompass several subsets initially identified by their expression of specific cell surface molecules and later shown to excel in distinct functions and to develop under the instruction of different transcription factors or cytokines. Very few cell surface molecules are expressed in a specific manner on any immune cell type. Hence, to identify cell types, the sole use of a small number of cell surface markers in classical flow cytometry can be deceiving. Moreover, the markers currently used to define mononuclear phagocyte subsets vary depending on the tissue and animal species studied and even between laboratories. This has led to confusion in the definition of DC subset identity and in their attribution of specific functions. There is a strong need to identify a rigorous and consensus way to define mononuclear phagocyte subsets, with precise guidelines potentially applicable throughout tissues and species. We will discuss the advantages, drawbacks and complementarities of different methodologies: cell surface phenotyping, ontogeny, functional characterization and molecular profiling. We will advocate that gene expression profiling is a very rigorous, largely unbiased and accessible method to define the identity of mononuclear phagocyte subsets, which strengthens and refines surface phenotyping. It is uniquely powerful to yield new, experimentally testable, hypotheses on the ontogeny or functions of mononuclear phagocyte subsets, their molecular regulation and their evolutionary conservation. We propose defining cell populations based on a combination of cell surface phenotyping, expression analysis of hallmark genes and robust functional assays, in order to reach a consensus and integrate faster the huge but scattered knowledge accumulated by different laboratories on different cell types

  8. GM-CSF Controls Nonlymphoid Tissue Dendritic Cell Homeostasis but Is Dispensable for the Differentiation of Inflammatory Dendritic Cells

    OpenAIRE

    Greter, Melanie; Helft, Julie; Chow, Andrew; Hashimoto, Daigo; Mortha, Arthur; Agudo-Cantero, Judith; Bogunovic, Milena; Gautier, Emmanuel L.; Miller, Jennifer; Leboeuf, Marylene; Lu, Geming; Aloman, Costica; Brown, Brian D.; Pollard, Jeffrey W.; Xiong, Huabao

    2012-01-01

    GM-CSF (Csf-2) is a critical cytokine for the in vitro generation of dendritic cells (DCs) and is thought to control the development of inflammatory DCs and resident CD103(+) DCs in some tissues. Here we showed that in contrast to the current understanding, Csf-2 receptor acts in the steady state to promote the survival and homeostasis of nonlymphoid tissue-resident CD103(+) and CD11b(+) DCs. Absence of Csf-2 receptor on lung DCs abrogated the induction of CD8(+) T cell immunity after immuniz...

  9. Radiation tolerance of boron doped dendritic web silicon solar cells

    Science.gov (United States)

    Rohatgi, A.

    1980-01-01

    The potential of dendritic web silicon for giving radiation hard solar cells is compared with the float zone silicon material. Solar cells with n(+)-p-P(+) structure and approximately 15% (AMl) efficiency were subjected to 1 MeV electron irradiation. Radiation tolerance of web cell efficiency was found to be at least as good as that of the float zone silicon cell. A study of the annealing behavior of radiation-induced defects via deep level transient spectroscopy revealed that E sub v + 0.31 eV defect, attributed to boron-oxygen-vacancy complex, is responsible for the reverse annealing of the irradiated cells in the temperature range of 150 to 350 C.

  10. Immune modulation by dendritic-cell-based cancer vaccines

    Indian Academy of Sciences (India)

    CHAITANYA KUMAR; SAKSHI KOHLI; POONAMALLE PARTHASARATHY BAPSY; ASHOK KUMAR VAID; MINISH JAIN; VENKATA SATHYA SURESH ATTILI; BANDANA SHARAN

    2017-03-01

    The interplay between host immunity and tumour cells has opened the possibility of targeting tumour cells bymodulation of the human immune system. Cancer immunotherapy involves the treatment of a tumour by utilizing therecombinant human immune system components to target the pro-tumour microenvironment or by revitalizing theimmune system with the ability to kill tumour cells by priming the immune cells with tumour antigens. In this review,current immunotherapy approaches to cancer with special focus on dendritic cell (DC)-based cancer vaccines arediscussed. Some of the DC-based vaccines under clinical trials for various cancer types are highlighted. Establishingtumour immunity involves a plethora of immune components and pathways; hence, combining chemotherapy,radiation therapy and various arms of immunotherapy, after analysing the benefits of individual therapeutic agents,might be beneficial to the patient.

  11. Polyelectrolyte coating of ferumoxytol nanoparticles for labeling of dendritic cells

    Science.gov (United States)

    Celikkin, Nehar; Jakubcová, Lucie; Zenke, Martin; Hoss, Mareike; Wong, John Erik; Hieronymus, Thomas

    2015-04-01

    Engineered magnetic nanoparticles (MNPs) are emerging to be used as cell tracers, drug delivery vehicles, and contrast agents for magnetic resonance imaging (MRI) for enhanced theragnostic applications in biomedicine. In vitro labeling of target cell populations with MNPs and their implantation into animal models and patients shows promising outcomes in monitoring successful cell engraftment, differentiation and migration by using MRI. Dendritic cells (DCs) are professional antigen-presenting cells that initiate adaptive immune responses. Thus, DCs have been the focus of cellular immunotherapy and are increasingly applied in clinical trials. Here, we addressed the coating of different polyelectrolytes (PE) around ferumoxytol particles using the layer-by-layer technique. The impact of PE-coated ferumoxytol particles for labeling of DCs and Flt3+ DC progenitors was then investigated. The results from our studies revealed that PE-coated ferumoxytol particles can be readily employed for labeling of DC and DC progenitors and thus are potentially suitable as contrast agents for MRI tracking.

  12. Dendritic Cell Regulation by Cannabinoid-Based Drugs

    Directory of Open Access Journals (Sweden)

    Mattias Svensson

    2010-08-01

    Full Text Available Cannabinoid pharmacology has made important advances in recent years after the cannabinoid system was discovered. Studies in experimental models and in humans have produced promising results using cannabinoid-based drugs for the treatment of obesity and cancer, as well as neuroinflammatory and chronic inflammatory diseases. Moreover, as we discuss here, additional studies also indicates that these drugs have immunosuppressive and anti-inflammatory properties including modulation of immune cell function. Thus, manipulation of the endocannabinoid system in vivo may provide novel therapeutic strategies against inflammatory disorders. At least two types of cannabinoid receptors, cannabinoid 1 and cannabinoid 2 receptors are expressed on immune cells such as dendritic cells (DC. Dendritic cells are recognized for their critical role in initiating and maintaining immune responses. Therefore, DC are potential targets for cannabinoid-mediated modulation. Here, we review the effects of cannabinoids on DC and provide some perspective concerning the therapeutic potential of cannabinoids for the treatment of human diseases involving aberrant inflammatory processes.

  13. Cord blood mesenchymal stem cells propel human dendritic cells to an intermediate maturation state and boost interleukin-12 production by mature dendritic cells.

    NARCIS (Netherlands)

    Berk, L.C.J. van den; Roelofs, H.; Huijs, T.; Siebers-Vermeulen, K.G.C.; Raymakers, R.A.P.; Kogler, G.; Figdor, C.G.; Torensma, R.

    2009-01-01

    Pathogen-derived entities force the tissue-resident dendritic cells (DCs) towards a mature state, followed by migration to the draining lymph node to present antigens to T cells. Bone marrow mesenchymal stem cells (MSCs) modulate the differentiation, maturation and function of DCs. In umbilical cord

  14. GABAergic interneurons targeting dendrites of pyramidal cells in the CA1 area of the hippocampus.

    Science.gov (United States)

    Klausberger, Thomas

    2009-09-01

    The dendrites of pyramidal cells are active compartments capable of independent computations, input/output transformation and synaptic plasticity. Pyramidal cells in the CA1 area of the hippocampus receive 92% of their GABAergic input onto dendrites. How does this GABAergic input participate in dendritic computations of pyramidal cells? One key to understanding their contribution to dendritic computation lies in the timing of GABAergic input in relation to excitatory transmission, back-propagating action potentials, Ca(2+) spikes and subthreshold membrane dynamics. The issue is further complicated by the fact that dendritic GABAergic inputs originate from numerous distinct sources operating with different molecular machineries and innervating different subcellular domains of pyramidal cell dendrites. The GABAergic input from distinct sources is likely to contribute differentially to dendritic computations. In this review, I describe four groups of GABAergic interneuron according to their expression of parvalbumin, cholecystokinin, axonal arborization density and long-range projections. These four interneuron groups contain at least 12 distinct cell types, which innervate mainly or exclusively the dendrites of CA1 pyramidal cells. Furthermore, I summarize the different spike timing of distinct interneuron types during gamma, theta and ripple oscillations in vivo, and I discuss some of the open questions on how GABAergic input modulates dendritic operations in CA1 pyramidal cells.

  15. Clinical application of dendritic cells in cancer vaccination therapy

    DEFF Research Database (Denmark)

    Svane, Inge Marie; Soot, Mette Line; Buus, Søren

    2003-01-01

    for large-scale generation of dendritic cells for clinical applications has made possible phase I/II studies designed to analyze the toxicity, feasibility and efficacy of this approach. In clinical trials, DC-based vaccination of patients with advanced cancer has in many cases led to immunity...... endpoints, including toxicity and response evaluation. This paper aims to review the technical aspects and clinical impact of vaccination trials, focusing on the generation of DC-based vaccines, evaluation of immunologic parameters and design of clinical trials necessary to meet the need for good laboratory...

  16. 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.

  17. Dendritic cell-based cancer immunotherapy for colorectal cancer.

    Science.gov (United States)

    Kajihara, Mikio; Takakura, Kazuki; Kanai, Tomoya; Ito, Zensho; Saito, Keisuke; Takami, Shinichiro; Shimodaira, Shigetaka; Okamoto, Masato; Ohkusa, Toshifumi; Koido, Shigeo

    2016-05-01

    Colorectal cancer (CRC) is one of the most common cancers and a leading cause of cancer-related mortality worldwide. Although systemic therapy is the standard care for patients with recurrent or metastatic CRC, the prognosis is extremely poor. The optimal sequence of therapy remains unknown. Therefore, alternative strategies, such as immunotherapy, are needed for patients with advanced CRC. This review summarizes evidence from dendritic cell-based cancer immunotherapy strategies that are currently in clinical trials. In addition, we discuss the possibility of antitumor immune responses through immunoinhibitory PD-1/PD-L1 pathway blockade in CRC patients.

  18. Functional identification of dendritic cells in the teleost model, rainbow trout (Oncorhynchus mykiss).

    Science.gov (United States)

    Bassity, Elizabeth; Clark, Theodore G

    2012-01-01

    Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro.

  19. Functional identification of dendritic cells in the teleost model, rainbow trout (Oncorhynchus mykiss.

    Directory of Open Access Journals (Sweden)

    Elizabeth Bassity

    Full Text Available Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss, with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro.

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

    NARCIS (Netherlands)

    Buschow, S.I.

    2006-01-01

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

  1. First Genomic Analysis of Dendritic Cells from Lung and Draining Lymph Nodes in Murine Asthma

    Directory of Open Access Journals (Sweden)

    Thomas Tschernig

    2015-01-01

    Full Text Available Asthma is the consequence of allergic inflammation in the lung compartments and lung-draining lymph nodes. Dendritic cells initiate and promote T cell response and drive it to immunity or allergy. However, their modes of action during asthma are poorly understood. In this study, an allergic inflammation with ovalbumin was induced in 38 mice versus 42 control animals. After ovalbumin aerosol challenge, conventional dendritic cells (CD11c/MHCII/CD8 were isolated from the lungs and the draining lymph nodes by means of magnetic cell sorting followed by fluorescence-activated cell sorting. A comparative transcriptional analysis was performed using gene arrays. In general, many transcripts are up- and downregulated in the CD8− dendritic cells of the allergic inflamed lung tissue, whereas few genes are regulated in CD8+ dendritic cells. The dendritic cells of the lymph nodes also showed minor transcriptional changes. The data support the relevance of the CD8− conventional dendritic cells but do not exclude distinct functions of the small population of CD8+ dendritic cells, such as cross presentation of external antigen. So far, this is the first approach performing gene arrays in dendritic cells obtained from lung tissue and lung-draining lymph nodes of asthmatic-like mice.

  2. The impact of extracellular acidosis on dendritic cell function.

    Science.gov (United States)

    Vermeulen, Mónica Elba; Gamberale, Romina; Trevani, Analía Silvina; Martínez, Diego; Ceballos, Ana; Sabatte, Juan; Giordano, Mirta; Geffner, Jorge Raúl

    2004-01-01

    Dendritic cells (DCs) are the most efficient antigen-presenting cells. They are activated in the periphery by conserved pathogen molecules and by inflammatory mediators produced by a variety of cell types in response to danger signals. It is widely appreciated that inflammatory responses in peripheral tissues are usually associated with the development of acidic microenvironments. Surprisingly, there are relatively few studies directed to analyze the effect of extracellular acidosis on the immune response. We focus on the influence of extracellular acidosis on the function of immature DCs. The results presented here show that acidosis activates DCs. It increases the acquisition of extracellular antigens for MHC class I-restricted presentation and the ability of antigen-pulsed DCs to induce both specific CD8+ CTL and B-cell responses. These findings may have important implications to our understanding of the mechanisms through which DCs sense the presence of infection or inflammation in nonlymphoid tissues.

  3. Apoptosis and systemic autoimmunity: the dendritic cell connection

    Directory of Open Access Journals (Sweden)

    AA Manfredi

    2009-12-01

    Full Text Available Much effort has been devoted in recent years to the events linking recognition and disposal of apoptotic cells to sustained immunity towards the antigens they contain. Programmed death via apoptosis indeed provides most of the raw material the immune system exploits to establish self tolerance, i.e. to learn how to distinguish between self constituents and foreign antigens, belonging to invading pathogens. In parallel, events occurring during cell death may enable a restricted array of molecules endowed with diverse structure, function and intracellular distribution to satisfy the requirement to evoke and maintain autoimmune responses. Dendritic cells (DCs, the most potent antigen presenting cells, appear to play a crucial role. Here we will discuss some of the constrains regulating the access of dying cells’ antigens to DCs, as well as censorship mechanisms that prevent their maturation and the full explication of their antigen presenting function.

  4. Topical vaccination with functionalized particles targeting dendritic cells.

    Science.gov (United States)

    Baleeiro, Renato B; Wiesmüller, Karl-Heinz; Reiter, Yoran; Baude, Barbara; Dähne, Lars; Patzelt, Alexa; Lademann, Jürgen; Barbuto, José A; Walden, Peter

    2013-08-01

    Needle-free vaccination, for reasons of safety, economy, and convenience, is a central goal in vaccine development, but it also needs to meet the immunological requirements for efficient induction of prophylactic and therapeutic immune responses. Combining the principles of noninvasive delivery to dendritic cells (DCs) through skin and the immunological principles of cell-mediated immunity, we developed microparticle-based topical vaccines. We show here that the microparticles are efficient carriers for coordinated delivery of the essential vaccine constituents to DCs for cross-presentation of the antigens and stimulation of T-cell responses. When applied to the skin, the microparticles penetrate into hair follicles and target the resident DCs, the immunologically most potent cells and site for induction of efficient immune responses. The microparticle vaccine principle can be applied to different antigen formats such as peptides and proteins, or nucleic acids coding for the antigens.

  5. Dendritic Cell-Based Immunotherapy for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Hanka Jähnisch

    2010-01-01

    Full Text Available Dendritic cells (DCs are professional antigen-presenting cells (APCs, which display an extraordinary capacity to induce, sustain, and regulate T-cell responses providing the opportunity of DC-based cancer vaccination strategies. Thus, clinical trials enrolling prostate cancer patients were conducted, which were based on the administration of DCs loaded with tumor-associated antigens. These clinical trials revealed that DC-based immunotherapeutic strategies represent safe and feasible concepts for the induction of immunological and clinical responses in prostate cancer patients. In this context, the administration of the vaccine sipuleucel-T consisting of autologous peripheral blood mononuclear cells including APCs, which were pre-exposed in vitro to the fusion protein PA2024, resulted in a prolonged overall survival among patients with metastatic castration-resistent prostate cancer. In April 2010, sipuleucel-T was approved by the United States Food and Drug Administration for prostate cancer therapy.

  6. 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.

  7. Intestinal dendritic cells in the regulation of mucosal immunity

    DEFF Research Database (Denmark)

    Bekiaris, Vasileios; Persson, Emma K.; Agace, William Winston

    2014-01-01

    immune cells within the mucosa must suitably respond to maintain intestinal integrity, while also providing the ability to mount effective immune responses to potential pathogens. Dendritic cells (DCs) are sentinel immune cells that play a central role in the initiation and differentiation of adaptive...... immune responses. In the intestinal mucosa, DCs are located diffusely throughout the intestinal lamina propria, within gut-associated lymphoid tissues, including Peyer's patches and smaller lymphoid aggregates, as well as in intestinal-draining lymph nodes, including mesenteric lymph nodes....... The recognition that dietary nutrients and microbial communities in the intestine influence both mucosal and systemic immune cell development and function as well as immune-mediated disease has led to an explosion of literature in mucosal immunology in recent years and a growing interest in the functionality...

  8. Cross-Regulation of Two Type I Interferon Signaling Pathways in Plasmacytoid Dendritic Cells Controls Anti-malaria Immunity and Host Mortality.

    Science.gov (United States)

    Yu, Xiao; Cai, Baowei; Wang, Mingjun; Tan, Peng; Ding, Xilai; Wu, Jian; Li, Jian; Li, Qingtian; Liu, Pinghua; Xing, Changsheng; Wang, Helen Y; Su, Xin-Zhuan; Wang, Rong-Fu

    2016-11-15

    Type I interferon (IFN) is critical for controlling pathogen infection; however, its regulatory mechanisms in plasmacytoid cells (pDCs) still remain unclear. Here, we have shown that nucleic acid sensors cGAS-, STING-, MDA5-, MAVS-, or transcription factor IRF3-deficient mice produced high amounts of type I IFN-α and IFN-β (IFN-α/β) in the serum and were resistant to lethal plasmodium yoelii YM infection. Robust IFN-α/β production was abolished when gene encoding nucleic acid sensor TLR7, signaling adaptor MyD88, or transcription factor IRF7 was ablated or pDCs were depleted. Further, we identified SOCS1 as a key negative regulator to inhibit MyD88-dependent type I IFN signaling in pDCs. Finally, we have demonstrated that pDCs, cDCs, and macrophages were required for generating IFN-α/β-induced subsequent protective immunity. Thus, our findings have identified a critical regulatory mechanism of type I IFN signaling in pDCs and stage-specific function of immune cells in generating potent immunity against lethal YM infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Ebola virus infection induces irregular dendritic cell gene expression.

    Science.gov (United States)

    Melanson, Vanessa R; Kalina, Warren V; Williams, Priscilla

    2015-02-01

    Filoviruses subvert the human immune system in part by infecting and replicating in dendritic cells (DCs). Using gene arrays, a phenotypic profile of filovirus infection in human monocyte-derived DCs was assessed. Monocytes from human donors were cultured in GM-CSF and IL-4 and were infected with Ebola virus Kikwit variant for up to 48 h. Extracted DC RNA was analyzed on SuperArray's Dendritic and Antigen Presenting Cell Oligo GEArray and compared to uninfected controls. Infected DCs exhibited increased expression of cytokine, chemokine, antiviral, and anti-apoptotic genes not seen in uninfected controls. Significant increases of intracellular antiviral and MHC I and II genes were also noted in EBOV-infected DCs. However, infected DCs failed to show any significant difference in co-stimulatory T-cell gene expression from uninfected DCs. Moreover, several chemokine genes were activated, but there was sparse expression of chemokine receptors that enabled activated DCs to home to lymph nodes. Overall, statistically significant expression of several intracellular antiviral genes was noted, which may limit viral load but fails to stop replication. EBOV gene expression profiling is of vital importance in understanding pathogenesis and devising novel therapeutic treatments such as small-molecule inhibitors.

  10. Myeloid dendritic cells: Development, functions, and role in atherosclerotic inflammation.

    Science.gov (United States)

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

    2015-06-01

    Myeloid dendritic cells (mDCs) comprise a heterogeneous population of professional antigen-presenting cells, which are responsible for capture, processing, and presentation of antigens on their surface to T cells. mDCs serve as a bridge linking adaptive and innate immune responses. To date, the development of DC lineage in bone marrow is better characterized in mice than in humans. DCs and macrophages share the common myeloid progenitor called macrophage-dendritic cell progenitor (MDP) that gives rise to monocytoid lineage and common DC progenitors (CDPs). CDP in turn gives rise to plasmacytoid DCs and predendritic cells (pre-mDCs) that are common precursor of myeloid CD11b+ and CD8α(+) DCs. The development and commitment of mDCs is regulated by several transcription and hematopoietic growth factors of which CCr7, Zbtb46, and Flt3 represent 'core' genes responsible for development and functional and phenotypic maintenance of mDCs. mDCs were shown to be involved in the pathogenesis of many autoimmune and inflammatory diseases including atherosclerosis. In atherogenesis, different subsets of mDCs could possess both proatherogenic (e.g. proinflammatory) and atheroprotective (e.g. anti-inflammatory and tolerogenic) activities. The proinflammatory role of mDCs is consisted in production of inflammatory molecules and priming proinflammatory subsets of effector T cells. In contrast, tolerogenic mDCs fight against inflammation through arrest of activity of proinflammatory T cells and macrophages and induction of immunosuppressive regulatory T cells. Microenvironmental conditions trigger differentiation of mDCs to acquire proinflammatory or regulatory properties.

  11. A multifunctional core-shell nanoparticle for dendritic cell-based cancer immunotherapy

    Science.gov (United States)

    Cho, Nam-Hyuk; Cheong, Taek-Chin; Min, Ji Hyun; Wu, Jun Hua; Lee, Sang Jin; Kim, Daehong; Yang, Jae-Seong; Kim, Sanguk; Kim, Young Keun; Seong, Seung-Yong

    2011-10-01

    Dendritic cell-based cancer immunotherapy requires tumour antigens to be delivered efficiently into dendritic cells and their migration to be monitored in vivo. Nanoparticles have been explored as carriers for antigen delivery, but applications have been limited by the toxicity of the solvents used to make nanoparticles, and by the need to use transfection agents to deliver nanoparticles into cells. Here we show that an iron oxide-zinc oxide core-shell nanoparticle can deliver carcinoembryonic antigen into dendritic cells while simultaneously acting as an imaging agent. The nanoparticle-antigen complex is efficiently taken up by dendritic cells within one hour and can be detected in vitro by confocal microscopy and in vivo by magnetic resonance imaging. Mice immunized with dendritic cells containing the nanoparticle-antigen complex showed enhanced tumour antigen specific T-cell responses, delayed tumour growth and better survival than controls.

  12. Cryptococcus neoformans activates bone marrow-derived conventional dendritic cells rather than plasmacytoid dendritic cells and down-regulates macrophages.

    Science.gov (United States)

    Siegemund, Sabine; Alber, Gottfried

    2008-04-01

    Induction of IL-12 and IL-23 is essential for protective immunity against Cryptococcusneoformans. The contribution of dendritic cells vs. macrophages to IL-12/23 production in response to C. neoformans infection is unclear. Activation of conventional bone marrow-derived dendritic cells (BMDC), plasmacytoid BMDC, and bone marrow-derived macrophages (BMMPhi) was assessed by analyzing cytokine responses and the expression of MHC-II, CD86, and CD80 in each cell type. Cryptococcus neoformans induced the release of IL-12/23p40 by BMDC, but not by BMMPhi, in a TLR2- and TLR4-independent but MyD88-dependent manner. Conventional BMDC rather than plasmacytoid BMDC up-regulated MHC-II and CD86, while BMMPhi down-regulated MHC-II and CD86 in response to C. neoformans. The up-regulation of MHC-II and CD86 on BMDC required MyD88. Our data point to conventional DC as critical IL-12/23-producing antigen-presenting cells during cryptococcosis.

  13. Ragweed subpollen particles of respirable size activate human dendritic cells.

    Directory of Open Access Journals (Sweden)

    Kitti Pazmandi

    Full Text Available Ragweed (Ambrosia artemisiifolia pollen grains, which are generally considered too large to reach the lower respiratory tract, release subpollen particles (SPPs of respirable size upon hydration. These SPPs contain allergenic proteins and functional NAD(PH oxidases. In this study, we examined whether exposure to SPPs initiates the activation of human monocyte-derived dendritic cells (moDCs. We found that treatment with freshly isolated ragweed SPPs increased the intracellular levels of reactive oxygen species (ROS in moDCs. Phagocytosis of SPPs by moDCs, as demonstrated by confocal laser-scanning microscopy, led to an up-regulation of the cell surface expression of CD40, CD80, CD86, and HLA-DQ and an increase in the production of IL-6, TNF-α, IL-8, and IL-10. Furthermore, SPP-treated moDCs had an increased capacity to stimulate the proliferation of naïve T cells. Co-culture of SPP-treated moDCs with allogeneic CD3(+ pan-T cells resulted in increased secretion of IFN-γ and IL-17 by T cells of both allergic and non-allergic subjects, but induced the production of IL-4 exclusively from the T cells of allergic individuals. Addition of exogenous NADPH further increased, while heat-inactivation or pre-treatment with diphenyleneiodonium (DPI, an inhibitor of NADPH oxidases, strongly diminished, the ability of SPPs to induce phenotypic and functional changes in moDCs, indicating that these processes were mediated, at least partly, by the intrinsic NAD(PH oxidase activity of SPPs. Collectively, our data suggest that inhaled ragweed SPPs are fully capable of activating dendritic cells (DCs in the airways and SPPs' NAD(PH oxidase activity is involved in initiation of adaptive immune responses against innocuous pollen proteins.

  14. Dendritic-tumor fusion cells in cancer immunotherapy.

    Science.gov (United States)

    Takakura, Kazuki; Kajihara, Mikio; Ito, Zensho; Ohkusa, Toshifumi; Gong, Jianlin; Koido, Shigeo

    2015-03-01

    A promising area of clinical investigation is the use of cancer immunotherapy to treat cancer patients. Dendritic cells (DCs) operate as professional antigen-presenting cells (APCs) and play a critical role in the induction of antitumor immune responses. Thus, DC-based cancer immunotherapy represents a powerful strategy. One DC-based cancer immunotherapy strategy that has been investigated is the administration of fusion cells generated with DCs and whole tumor cells (DC-tumor fusion cells). The DC-tumor fusion cells can process a broad array of tumor-associated antigens (TAAs), including unidentified molecules, and present them through major histocompatibility complex (MHC) class I and II pathways in the context of co-stimulatory signals. Improving the therapeutic efficacy of DC-tumor fusion cell-based cancer immunotherapy requires increased immunogenicity of DCs and whole tumor cells. We discuss the potential ability of DC-tumor fusion cells to activate antigen-specific T cells and strategies to improve the immunogenicity of DC-tumor fusion cells as anticancer vaccines.

  15. Follicular Dendritic Cells Retain Infectious HIV in Cycling Endosomes.

    Directory of Open Access Journals (Sweden)

    Balthasar A Heesters

    2015-12-01

    Full Text Available Despite the success of antiretroviral therapy (ART, it does not cure Human Immunodeficiency Virus (HIV and discontinuation results in viral rebound. Follicular dendritic cells (FDC are in direct contact with CD4+ T cells and they retain intact antigen for prolonged periods. We found that human FDC isolated from patients on ART retain infectious HIV within a non-degradative cycling compartment and transmit infectious virus to uninfected CD4 T cells in vitro. Importantly, treatment of the HIV+ FDC with a soluble complement receptor 2 purges the FDC of HIV virions and prevents viral transmission in vitro. Our results provide an explanation for how FDC can retain infectious HIV for extended periods and suggest a therapeutic strategy to achieve cure in HIV-infected humans.

  16. Krebs cycle rewired for macrophage and dendritic cell effector functions.

    Science.gov (United States)

    Ryan, Dylan Gerard; O'Neill, Luke A J

    2017-07-07

    The Krebs cycle is an amphibolic pathway operating in the mitochondrial matrix of all eukaryotic organisms. In response to proinflammatory stimuli, macrophages and dendritic cells undergo profound metabolic remodelling to support the biosynthetic and bioenergetic requirements of the cell. Recently, it has been discovered that this metabolic shift also involves the rewiring of the Krebs cycle to regulate cellular metabolic flux and the accumulation of Krebs cycle intermediates, notably, citrate, succinate and fumarate. Interestingly, a new role for Krebs cycle intermediates as signalling molecules and immunomodulators that dictate the inflammatory response has begun to emerge. This review will discuss the latest developments in Krebs cycle rewiring and immune cell effector functions, with a particular focus on the regulation of cytokine production. © 2017 Federation of European Biochemical Societies.

  17. Imaging Findings of Follicular Dendritic Cell Sarcoma: Report of Four Cases

    Energy Technology Data Exchange (ETDEWEB)

    Long-Hua, Qiu; Xiao-Yuan, Feng [Affi liated HuaShan Hospital, Fudan University, Shanghai (China); Qin, Xiao; Ya-Jia, Gu; Jian, Wang [Affiliated Cancer Hospital, Fudan University, Shanghai (China)

    2011-02-15

    Follicular dendritic cell sarcoma is a rare malignant neoplasm and little is known about its radiological features. We present here four cases of follicular dendritic cell sarcomas and we provide the image characteristics of these tumors to help radiologists recognize this entity when making a diagnosis

  18. Cord blood dendritic cell subsets in African newborns exposed to Plasmodium falciparum in utero.

    NARCIS (Netherlands)

    Breitling, L.P.; Fendel, R.; Mordmueller, B.; Adegnika, A.A.; Kremsner, P.G.; Luty, A.J.F.

    2006-01-01

    Placental Plasmodium falciparum infection affects birth outcomes and sensitizes fetal lymphocytes to parasite antigens. We assessed the influence of maternal P. falciparum infection on fetal myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC), analyzing the cord blood of offspring o

  19. Quantification of blood dendritic cells in colorectal cancer patients during the course of disease.

    Science.gov (United States)

    Orsini, Giulia; Legitimo, Annalisa; Failli, Alessandra; Ferrari, Paola; Nicolini, Andrea; Spisni, Roberto; Miccoli, Paolo; Consolini, Rita

    2014-04-01

    Colorectal cancer is a malignancy with poor prognosis that might be associated with defective immune function. The aim of the present study was to investigate circulating dendritic cells in colorectal cancer patients, in order to contribute to elucidate tumor-escape mechanisms and to point out a possible correlation with the clinical condition of the disease. Therefore, we enumerated ex vivo myeloid and plasmacytoid dendritic cells, through multicolor flow cytometry, in 26 colorectal patients and 33 healthy controls. Furthermore we performed several analyses at determined time points in order to define the immunological trend of cancer patients after surgery and other conventional treatments. At the pre-operative time point the absolute number of plasmacytoid dendritic cells in cancer patients was significantly reduced in comparison to controls, this result being mainly referred to stage III-IV patients. The number of myeloid dendritic cells did not show any significant difference compared to healthy controls; interestingly the expression of the tolerogenic antigen CD85k was significantly higher on cancer patients' myeloid dendritic cells than controls'. At the following samplings, circulating dendritic cell absolute number did not show any difference compared to controls. Conclusively the impairment of the number of circulating dendritic cells may represent one of the tumor escape mechanisms occurring in colorectal cancer. These alterations seem to be correlated to cancer progression. Our work sheds light on one of dendritic cell-based tumor immune escape mechanisms. This knowledge may be useful to the development of more effective immunotherapeutic strategies.

  20. Development of Type 1 Diabetes: Monocytes and dendritic cells in the pancreas

    NARCIS (Netherlands)

    J.M.C. Welzen-Coppens (Jojanneke)

    2013-01-01

    textabstractThis thesis focuses on the presence of precursors for dendritic cells and the characterization of dendritic cell subsets in the normal pancreas in mice and humans as well as in the pancreas of the NOD mouse, a type 1 diabetes mouse model. Therefore, we give a short introduction to

  1. Identification of a novel immunoregulatory signaling pathway exploited by M. tuberculosis in dendritic cells

    DEFF Research Database (Denmark)

    Laursen, Janne Marie; Schoof, Erwin; Søndergaard, Jonas Nørskov;

    to the highly sophisticated infectious machinery employed by the bacterium. The dendritic cell (DC) plays a crucial role in shaping the nature of the immune response after exposure to pathogens, and the interaction between M. tuberculosis and the dendritic cell is of profound importance for the course...

  2. Development of Type 1 Diabetes: Monocytes and dendritic cells in the pancreas

    NARCIS (Netherlands)

    J.M.C. Welzen-Coppens (Jojanneke)

    2013-01-01

    textabstractThis thesis focuses on the presence of precursors for dendritic cells and the characterization of dendritic cell subsets in the normal pancreas in mice and humans as well as in the pancreas of the NOD mouse, a type 1 diabetes mouse model. Therefore, we give a short introduction to dendri

  3. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2013-01-15

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by

  4. An improved method for culturing cerebellar Purkinje cells with differentiated dendrites under a mixed monolayer setting.

    Science.gov (United States)

    Furuya, S; Makino, A; Hirabayashi, Y

    1998-11-01

    We report here a novel cell culture protocol which facilitates in vitro survival and dendritic differentiation of cerebellar Purkinje cells in a monolayer, mixed culture setting. We found that the type of culture medium is a critical factor for the maintenance of these cells. Purkinje cells present in the single cell suspension of embryonic rat cerebellum were best maintained in a medium based on Dulbecco's modified Eagle's medium (DMEM)/F-12 without the addition of known neurotrophic factors. These cells maintained in DMEM/F-12-based media displayed an approximately 2.5-3.5-fold increase in survival compared with cells maintained in the widely used Basal Medium Eagle's (BME)-based serum-free culture medium with the same supplements. This novel protocol permits not only enhanced survival but also accelerated, improved dendritic differentiation of these cells. Purkinje cells developed highly branched spiny dendrites by 14-16 days in vitro, which matches the time course of the dendritic growth of these cells in vivo. The Purkinje cells expressed metabotropic glutamate receptor 1alpha in the cell bodies and branched dendrites, and the intradendritic calcium concentration increased when trans-ACPD, a selective agonist of this receptor, was applied. This novel protocol allows the development of functional branched dendrites and therefore is useful for electrophysiological and ion-imaging studies on dendrites of Purkinje cells grown in vitro.

  5. Democracy-Independence Trade-Off in Oscillating Dendrites and Its Implications for Grid Cells

    Science.gov (United States)

    Remme, Michiel W.H.; Lengyel, Máté; Gutkin, Boris S.

    2010-01-01

    Summary Dendritic democracy and independence have been characterized for near-instantaneous processing of synaptic inputs. However, a wide class of neuronal computations requires input integration on long timescales. As a paradigmatic example, entorhinal grid fields have been thought to be generated by the democratic summation of independent dendritic oscillations performing direction-selective path integration. We analyzed how multiple dendritic oscillators embedded in the same neuron integrate inputs separately and determine somatic membrane voltage jointly. We found that the interaction of dendritic oscillations leads to phase locking, which sets an upper limit on the timescale for independent input integration. Factors that increase this timescale also decrease the influence that the dendritic oscillations exert on somatic voltage. In entorhinal stellate cells, interdendritic coupling dominates and causes these cells to act as single oscillators. Our results suggest a fundamental trade-off between local and global processing in dendritic trees integrating ongoing signals. PMID:20471355

  6. Distinct gut-derived lactic acid bacteria elicit divergent dendritic cell-mediated NK cell responses

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Zeuthen, Louise Hjerrild; Christensen, Hanne

    2007-01-01

    Lactic acid bacteria (LAB) are abundant in the gastrointestinal tract where they continuously regulate the immune system. NK cells are potently activated by dendritic cells (DCs) matured by inflammatory stimuli, and NK cells are present in the gut epithelium and in mesenteric lymph nodes...

  7. Human and murine model cell lines for dendritic cell biology evaluated.

    NARCIS (Netherlands)

    Helden, S.F.G. van; Leeuwen, F.N. van; Figdor, C.G.

    2008-01-01

    Dendritic cells (DCs) are specialized antigen presenting cells that link innate and adaptive immune responses. As key mediators of T cell dependent immunity, DCs are considered primary targets for initiating immune responses in infectious diseases and cancer. Conversely, DCs can also play an importa

  8. Antigen loading on dendritic cells affects the lell function in stimulating T cells.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the effect of antigen loading on dendritic cells (DC). Methods: DCs collected from peripheral blood monocytes were loaded with a tumor antigen from XG-7 cell line. These DCs were then co-cultured with allogeneic T cells and were compared with those DCs without antigen exposure.

  9. Dengue tropism for macrophages and dendritic cells : the host cell effect

    NARCIS (Netherlands)

    Flipse, Jacky; Torres, Silvia; Diosa-Toro, Mayra; van der Ende-Metselaar, Heidi; Herrera-Rodriguez, Jose; Urcuqui-Inchima, Silvio; Huckriede, Anke; Rodenhuis-Zybert, Izabela A; Smit, Jolanda M

    2016-01-01

    Dengue virus infects immune cells, including monocytes, macrophages and dendritic cells (DC). We compared virus infectivity in macrophages and DC, and found that the virus-origin determined the cell tropism of progeny virus. The highest efficiency of re-infection was seen for macrophage-derived deng

  10. Clinical responses in patients with advanced colorectal cancer to a dendritic cell based vaccine

    DEFF Research Database (Denmark)

    Burgdorf, Stefan K; Fischer, Anders; Myschetzky, Peter S

    2008-01-01

    Patients with disseminated colorectal cancer have a poor prognosis. Preliminary studies have shown encouraging results from vaccines based on dendritic cells. The aim of this phase II study was to evaluate the effect of treating patients with advanced colorectal cancer with a cancer vaccine based...... on dendritic cells pulsed with an allogenic tumor cell lysate. Twenty patients with advanced colorectal cancer were consecutively enrolled. Dendritic cells (DC) were generated from autologous peripheral blood mononuclear cells and pulsed with allogenic tumor cell lysate containing high levels of cancer...

  11. Dendritic cell maturation and cross-presentation: timing matters!

    Science.gov (United States)

    Alloatti, Andrés; Kotsias, Fiorella; Magalhaes, Joao Gamelas; Amigorena, Sebastian

    2016-07-01

    As a population, dendritic cells (DCs) appear to be the best cross-presenters of internalized antigens on major histocompatibility complex class I molecules in the mouse. To do this, DCs have developed a number of unique and dedicated means to control their endocytic and phagocytic pathways: among them, the capacity to limit acidification of their phagosomes, to prevent proteolytic degradation, to delay fusion of phagosomes to lysosomes, to recruit ER proteins to phagosomes, and to export phagocytosed antigens to the cytosol. The regulation of phagocytic functions, and thereby of antigen processing and presentation by innate signaling, represents a critical level of integration of adaptive and innate immune responses. Understanding how innate signals control antigen cross-presentation is critical to define effective vaccination strategies for CD8(+) T-cell responses.

  12. Immunological Characterization of Whole Tumour Lysate-Loaded Dendritic Cells for Cancer Immunotherapy.

    Directory of Open Access Journals (Sweden)

    Veronica Rainone

    Full Text Available Dendritic cells play a key role as initiators of T-cell responses, and even if tumour antigen-loaded dendritic cells can induce anti-tumour responses, their efficacy has been questioned, suggesting a need to enhance immunization strategies.We focused on the characterization of bone marrow-derived dendritic cells pulsed with whole tumour lysate (TAA-DC, as a source of known and unknown antigens, in a mouse model of breast cancer (MMTV-Ras. Dendritic cells were evaluated for antigen uptake and for the expression of MHC class I/II and costimulatory molecules and markers associated with maturation.Results showed that antigen-loaded dendritic cells are characterized by a phenotypically semi-mature/mature profile and by the upregulation of genes involved in antigen presentation and T-cell priming. Activated dendritic cells stimulated T-cell proliferation and induced the production of high concentrations of IL-12p70 and IFN-γ but only low levels of IL-10, indicating their ability to elicit a TH1-immune response. Furthermore, administration of Antigen loaded-Dendritic Cells in MMTV-Ras mice evoked a strong anti-tumour response in vivo as demonstrated by a general activation of immunocompetent cells and the release of TH1 cytokines.Data herein could be useful in the design of antitumoral DC-based therapies, showing a specific activation of immune system against breast cancer.

  13. Tumour tissue microenvironment can inhibit dendritic cell maturation in colorectal cancer.

    LENUS (Irish Health Repository)

    Michielsen, Adriana J

    2011-01-01

    Inflammatory mediators in the tumour microenvironment promote tumour growth, vascular development and enable evasion of anti-tumour immune responses, by disabling infiltrating dendritic cells. However, the constituents of the tumour microenvironment that directly influence dendritic cell maturation and function are not well characterised. Our aim was to identify tumour-associated inflammatory mediators which influence the function of dendritic cells. Tumour conditioned media obtained from cultured colorectal tumour explant tissue contained high levels of the chemokines CCL2, CXCL1, CXCL5 in addition to VEGF. Pre-treatment of monocyte derived dendritic cells with this tumour conditioned media inhibited the up-regulation of CD86, CD83, CD54 and HLA-DR in response to LPS, enhancing IL-10 while reducing IL-12p70 secretion. We examined if specific individual components of the tumour conditioned media (CCL2, CXCL1, CXCL5) could modulate dendritic cell maturation or cytokine secretion in response to LPS. VEGF was also assessed as it has a suppressive effect on dendritic cell maturation. Pre-treatment of immature dendritic cells with VEGF inhibited LPS induced upregulation of CD80 and CD54, while CXCL1 inhibited HLA-DR. Interestingly, treatment of dendritic cells with CCL2, CXCL1, CXCL5 or VEGF significantly suppressed their ability to secrete IL-12p70 in response to LPS. In addition, dendritic cells treated with a combination of CXCL1 and VEGF secreted less IL-12p70 in response to LPS compared to pre-treatment with either cytokine alone. In conclusion, tumour conditioned media strongly influences dendritic cell maturation and function.

  14. Dendritic branching of olfactory bulb mitral and tufted cells: regulation by TrkB.

    Directory of Open Access Journals (Sweden)

    Fumiaki Imamura

    Full Text Available BACKGROUND: Projection neurons of mammalian olfactory bulb (OB, mitral and tufted cells, have dendrites whose morphologies are specifically differentiated for efficient odor information processing. The apical dendrite extends radially and arborizes in single glomerulus where it receives primary input from olfactory sensory neurons that express the same odor receptor. The lateral dendrites extend horizontally in the external plexiform layer and make reciprocal dendrodendritic synapses with granule cells, which moderate mitral/tufted cell activity. The molecular mechanisms regulating dendritic development of mitral/tufted cells is one of the unsolved important problems in the olfactory system. Here, we focused on TrkB receptors to test the hypothesis that neurotrophin-mediate mechanisms contributed to dendritic differentiation of OB mitral/tufted cells. PRINCIPAL FINDINGS: With immunohistochemical analysis, we found that the TrkB neurotrophin receptor is expressed by both apical and lateral dendrites of mitral/tufted cells and that expression is evident during the early postnatal days when these dendrites exhibit their most robust growth and differentiation. To examine the effect of TrkB activation on mitral/tufted cell dendritic development, we cultured OB neurons. When BDNF or NT4 were introduced into the cultures, there was a significant increase in the number of primary neurites and branching points among the mitral/tufted cells. Moreover, BDNF facilitated filopodial extension along the neurites of mitral/tufted cells. SIGNIFICANCE: In this report, we show for the first time that TrkB activation stimulates the dendritic branching of mitral/tufted cells in developing OB. This suggests that arborization of the apical dendrite in a glomerulus is under the tight regulation of TrkB activation.

  15. Mannosylated biodegradable polyethyleneimine for targeted DNA delivery to dendritic cells

    Directory of Open Access Journals (Sweden)

    Sun X

    2012-06-01

    Full Text Available Xun Sun, Simu Chen, Jianfeng Han, Zhirong ZhangKey Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, People’s Republic of ChinaBackground: To establish a potential gene-delivery system with the ability to deliver plasmid DNA to dendritic cells (DCs more efficiently and specifically, we designed and synthesized a low-molecular-weight polyethyleneimine and triethyleneglycol polymer (PEI–TEG and a series of its mannosylated derivatives.Methods: PEI–TEG was synthesized from PEI2000 and PEI600 with TEG as the cross-linker. PEI–TEG was then linked to mannose via a phenylisothiocyanate bridge to obtain man-PEI–TEG conjugates. The DNA conveyance abilities of PEI–TEG, man-PEI–TEG, as well as control PEI25k were evaluated by measuring their zeta potential, particle size, and DNA-binding abilities. The in vitro cytotoxicity, cell uptake, and transfection efficiency of these PEI/DNA complexes were examined on the DC2.4 cell line. Finally, a maturation experiment evaluated the effect of costimulatory molecules CD40, CD80, and CD86 on murine bone marrow-derived DCs (BMDCs using flow cytometry.Results: PEI–TEG and man-PEI–TEG were successfully synthesized and were shown to retain the excellent properties of PEI25k for condensing DNA. Compared with PEI–TEG as well as PEI25k, the man-PEI–TEG had less cytotoxicity and performed better in both cellular uptake and transfection assays in vitro. The results of the maturation experiment showed that all the PEI/DNA complexes induced an adequate upregulation of surface markers for DC maturation.Conclusion: These results demonstrated that man-PEI–TEG can be employed as a DC-targeting gene-delivery system.Keywords: dendritic cells, DCs, mannose, polyethyleneimine, PEI, gene delivery

  16. Chemoresistance of human monocyte-derived dendritic cells is regulated by IL-17A.

    Directory of Open Access Journals (Sweden)

    Selma Olsson Åkefeldt

    Full Text Available Dendritic cells initiate adaptive immune responses, leading either to control cancer by effector T cells or to exacerbate cancer by regulatory T cells that inhibit IFN-γ-mediated Th1-type response. Dendritic cells can also induce Th17-type immunity, mediated by IL-17A. However, the controversial role of this cytokine in cancer requires further investigations. We generated dendritic cells from peripheral blood monocytes to investigate lifespan, phenotype and chemoresistance of dendritic cells, treated with IL-17A with or without IFN-γ. Studying the expression of Bcl-2 family members, we demonstrated that dendritic cells constitutively express one pro-survival Bcl-2 member: MCL1. Immature dendritic cells were CD40(lowHLADR(low CD1a(+ MCL1(+, did not express CD14, CD68 or BCL2A1, and displayed a short 2-day lifespan. IL-17A-treated DC exhibited a semi-mature (CD40(high HLADR(low pre-M2 (CCL22(+ CD206(+ CD163(+ IL1RN(+ IL-10(- CXCL10(- IL-12(- mixed (CD1a(+ CD14+ CD68(+ macrophage-dendritic cell phenotype. They efficiently exerted mannose receptor-mediated endocytosis and did not produce superoxide anions, in the absence of TLR engagement. Interestingly, IL-17A promoted a long-term survival of dendritic cells, beyond 12 days, that correlated to BCL2A1 induction, a pro-survival Bcl-2 family member. BCL2A1 transcription was activated by NF-κB, downstream of IL-17A transduction. Thus, immature dendritic cells only express MCL1, whereas IL-17A-treated dendritic cells concomitantly expressed two pro-survival Bcl-2 family members: MCL1 and BCL2A1. These latter developed chemoresistance to 11 of the 17 chemotherapy agents tested. However, high doses of either vinblastine or cytarabine decreased MCL1 expression and induced dendritic cell death. When IL-17A is produced in vivo, administration of anti-IL-17A biotherapy may impair dendritic cell survival by targeting BCL2A1 expression. Consequently, depending on the effector or regulatory role of dendritic

  17. Uptake and intracellular trafficking of superantigens in dendritic cells.

    Directory of Open Access Journals (Sweden)

    María B Ganem

    Full Text Available Bacterial superantigens (SAgs are exotoxins produced mainly by Staphylococcus aureus and Streptococcus pyogenes that can cause toxic shock syndrome (TSS. According to current paradigm, SAgs interact directly and simultaneously with T cell receptor (TCR on the T cell and MHC class II (MHC-II on the antigen-presenting cell (APC, thereby circumventing intracellular processing to trigger T cell activation. Dendritic cells (DCs are professional APCs that coat nearly all body surfaces and are the most probable candidate to interact with SAgs. We demonstrate that SAgs are taken up by mouse DCs without triggering DC maturation. SAgs were found in intracellular acidic compartment of DCs as biologically active molecules. Moreover, SAgs co-localized with EEA1, RAB-7 and LAMP-2, at different times, and were then recycled to the cell membrane. DCs loaded with SAgs are capable of triggering in vitro lymphocyte proliferation and, injected into mice, stimulate T cells bearing the proper TCR in draining lymph nodes. Transportation and trafficking of SAgs in DCs might increase the local concentration of these exotoxins where they will produce the highest effect by promoting their encounter with both MHC-II and TCR in lymph nodes, and may explain how just a few SAg molecules can induce the severe pathology associated with TSS.

  18. Cancer Vaccine by Fusions of Dendritic and Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shigeo Koido

    2009-01-01

    Full Text Available Dendritic cells (DCs are potent antigen-presenting cells and play a central role in the initiation and regulation of primary immune responses. Therefore, their use for the active immunotherapy against cancers has been studied with considerable interest. The fusion of DCs with whole tumor cells represents in many ways an ideal approach to deliver, process, and subsequently present a broad array of tumor-associated antigens, including those yet to be unidentified, in the context of DCs-derived costimulatory molecules. DCs/tumor fusion vaccine stimulates potent antitumor immunity in the animal tumor models. In the human studies, T cells stimulated by DC/tumor fusion cells are effective in lysis of tumor cells that are used as the fusion partner. In the clinical trials, clinical and immunological responses were observed in patients with advanced stage of malignant tumors after being vaccinated with DC/tumor fusion cells, although the antitumor effect is not as vigorous as in the animal tumor models. This review summarizes recent advances in concepts and techniques that are providing new impulses to DCs/tumor fusions-based cancer vaccination.

  19. Unique proteomic signatures distinguish macrophages and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Lev Becker

    Full Text Available Monocytes differentiate into heterogeneous populations of tissue macrophages and dendritic cells (DCs that regulate inflammation and immunity. Identifying specific populations of myeloid cells in vivo is problematic, however, because only a limited number of proteins have been used to assign cellular phenotype. Using mass spectrometry and bone marrow-derived cells, we provided a global view of the proteomes of M-CSF-derived macrophages, classically and alternatively activated macrophages, and GM-CSF-derived DCs. Remarkably, the expression levels of half the plasma membrane proteins differed significantly in the various populations of cells derived in vitro. Moreover, the membrane proteomes of macrophages and DCs were more distinct than those of classically and alternatively activated macrophages. Hierarchical cluster and dual statistical analyses demonstrated that each cell type exhibited a robust proteomic signature that was unique. To interrogate the phenotype of myeloid cells in vivo, we subjected elicited peritoneal macrophages harvested from wild-type and GM-CSF-deficient mice to mass spectrometric and functional analysis. Unexpectedly, we found that peritoneal macrophages exhibited many features of the DCs generated in vitro. These findings demonstrate that global analysis of the membrane proteome can help define immune cell phenotypes in vivo.

  20. Interactions between airway epithelial cells and dendritic cells during viral infections using an in vitro co-culture model

    Science.gov (United States)

    Rationale: Historically, single cell culture models have been limited in pathological and physiological relevance. A co-culture model of dendritic cells (DCs) and differentiated human airway epithelial cells was developed to examine potential interactions between these two cell t...

  1. Properties of mouse retinal ganglion cell dendritic growth during postnatal development

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The property of dendritic growth dynamics during development is a subject of intense interest.Here,we investigated the dendritic motility of retinal ganglion cells (RGCs) during different developmental stages,using ex vivo mouse retina explant culture,Semliki Forest Virus transfection and time-lapse observations.The results illustrated that during development,the dendritic motility underwent a change from rapid growth to a relatively stable state,i.e.,at P0 (day of birth),RGC dendrites were in a highly active state,whereas at postnatal 13 (P13) they were more stable,and at P3 and P8,the RGCs were in an intermediate state.At any given developmental stage,RGCs of different types displayed the same dendritic growth rate and extent.Since the mouse is the most popular mammalian model for genetic manipulation,this study provided a methodological foundation for further exploring the regulatory mechanisms of dendritic development.

  2. Muscarinic regulation of Kenyon cell dendritic arborizations in adult worker honey bees.

    Science.gov (United States)

    Dobrin, Scott E; Herlihy, J Daniel; Robinson, Gene E; Fahrbach, Susan E

    2011-09-01

    The experience of foraging under natural conditions increases the volume of mushroom body neuropil in worker honey bees. A comparable increase in neuropil volume results from treatment of worker honey bees with pilocarpine, an agonist for muscarinic-type cholinergic receptors. A component of the neuropil growth induced by foraging experience is growth of dendrites in the collar region of the calyces. We show here, via analysis of Golgi-impregnated collar Kenyon cells with wedge arborizations, that significant increases in standard measures of dendritic complexity were also found in worker honey bees treated with pilocarpine. This result suggests that signaling via muscarinic-type receptors promotes the increase in Kenyon cell dendritic complexity associated with foraging. Treatment of worker honey bees with scopolamine, a muscarinic inhibitor, inhibited some aspects of dendritic growth. Spine density on the Kenyon cell dendrites varied with sampling location, with the distal portion of the dendritic field having greater total spine density than either the proximal or medial section. This observation may be functionally significant because of the stratified organization of projections from visual centers to the dendritic arborizations of the collar Kenyon cells. Pilocarpine treatment had no effect on the distribution of spines on dendrites of the collar Kenyon cells.

  3. Modulation of dendritic cell function by Trichomonas vaginalis-derived secretory products.

    Science.gov (United States)

    Song, Min-Ji; Lee, Jong-Joo; Nam, Young Hee; Kim, Tae-Gyun; Chung, Youn Wook; Kim, Mikyoung; Choi, Ye-Eun; Shin, Myeong Heon; Kim, Hyoung-Pyo

    2015-02-01

    Trichomoniasis caused by the parasitic protozoan Trichomonas vaginalis is the most common sexually transmitted disease in the world. Dendritic cells are antigen presenting cells that initiate immune responses by directing the activation and differentiation of naïve T cells. In this study, we analyzed the effect of Trichomonas vaginalis-derived Secretory Products on the differentiation and function of dendritic cells. Differentiation of bone marrow-derived dendritic cells in the presence of T. vaginalis-derived Secretory Products resulted in inhibition of lipopolysaccharide-induced maturation of dendritic cells, down-regulation of IL-12, and up-regulation of IL-10. The protein components of T. vaginalis-derived Secretory Products were shown to be responsible for altered function of bone marrow- derived dendritic cells. Chromatin immunoprecipitation assay demonstrated that IL-12 expression was regulated at the chromatin level in T. vaginalis-derived Secretory Productstreated dendritic cells. Our results demonstrated that T. vaginalis- derived Secretory Products modulate the maturation and cytokine production of dendritic cells leading to immune tolerance.

  4. Clinical significance of circulating dendritic cells in patients with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    T. Robak

    1992-01-01

    Full Text Available DENDRITIC cells are a complex group of mainly bone-marrow-derived leukocytes that play a role in autoimmune diseases. The total number of circulating dendritic cells (tDC, and their plasmacytoid dendritic cell (pDC and myeloid dendritic cell (mDC1 and mDC2 subpopulations were assessed using flow cytometry. The number of tDC and their subsets were significantly lower in systemic lupus erythematosus patients than in the control group. The count of tDC and their subsets correlated with the number of T cells. The number of tDC and pDC subpopulation were lower in the patients with lymphopenia and leucopoenia than in the patients without these symptoms. Our data suggest that fluctuations in blood dendritic cell count in systemic lupus erythematosus patients are much more significant in pDC than in mDC, what may be caused by their migration to the sites of inflammation including skin lesions. Positive correlation between dendritic cell number and TCD4+, TCD8+ and CD19+ B cells, testify of their interactions and influence on SLE pathogenesis. The association between dendritic cell number and clinical features seems to be less clear.

  5. Probiotic modulation of dendritic cells and T cell responses in the intestine

    NARCIS (Netherlands)

    Meijerink, M.; Wells, J.

    2010-01-01

    Over the past decade it has become clear that probiotic and commensal interactions with mucosal dendritic cells in the lamina propria or epithelial cells lining the mucosa can modulate specific functions of the mucosal immune system. Innate pattern-recognition receptors such as TLRs, NLRs and CLRs p

  6. Activated T cells recruit exosomes secreted by dendritic cells via LFA-1.

    NARCIS (Netherlands)

    Nolte-'t Hoen, E.N.; Buschow, S.I.; Anderton, S.M.; Stoorvogel, W.; Wauben, M.H.M.

    2009-01-01

    Dendritic cells (DCs) are known to secrete exosomes that transfer membrane proteins, like major histocompatibility complex class II, to other DCs. Intercellular transfer of membrane proteins is also observed during cognate interactions between DCs and CD4(+) T cells. The acquired proteins are functi

  7. The Comparison of Biologic Characteristics between Mice Embryonic Stem Cells and Bone Marrow Derived Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Junfeng Liu; Zhixu He; Dong Shen; Jin Huang; Haowen Wang

    2009-01-01

    OBJECTIVE This research was to induce dendritic cells (DCs)from mice embryonic stem cells and bone marrow mononuclear cells in vitro, and then compare the biologic characteristics of them.METHODS Embryonic stem cells (ESCs) suspending cultured in petri dishes were induced to generate embryonic bodies (EBs).Fourteen-day well-developed EBs were transferred to histological culture with the same medium and supplemented 25 ng/ml GM-CSF and 25 ng/ml IL-3. In the next 2 weeks, there were numerous immature DCs outgrown. Meantime, mononuclear cells isolated from mice bone marrow were induced to derive dendritic cells by supplementing 25 ng/ml GM-CSF and 25 ng/ml IL-4, and then the morphology, phenotype and function of both dendritic cells from different origins were examined.RESULTS Growing mature through exposure to lipopolysaccharide (LPS), both ESC-DCs and BM-DCs exhibited dramatic veils of cytoplasm and extensive dendrites on their surfaces, highly expressed CD11c, MHC-Ⅱ and CD86 with strong capacity to stimulate primary T cell responses in mixed leukocyte reaction (MLR).CONCLUSION ESC-DC has the same biologic characteristics as BM-DC, and it provides a new, reliable source for the functional research of DC and next produce corresponding anti-tumor vaccine.

  8. Study on biological characters of SGC7901 gastric cancer cell-dendritic cell fusion vaccines

    Institute of Scientific and Technical Information of China (English)

    Kun Zhang; Peng-Fen Gao; Pei-Wu Yu; Yun Rao; Li-Xin Zhou

    2006-01-01

    AIM: To detect the biological characters of the SGC7901 gastric cancer cell-dendritic cell fusion vaccines.METHODS: The suspending living SGC7901 gastric cancer cells and dendritic cells were induced to be fusioned by polyethylene glycol. Pure fusion cells were obtained by selective culture with the HAT/HT culture systems.The fusion cells were counted at different time points of culture and their growth curves were drawn to reflect their proliferative activities. The fusion cells were also cultured in culture medium to investigate whether they could grow into cell clones. MTT method was used to test the stimulating abilities of the fusion cells on T lymphocytes' proliferations. Moreover, the fusion cells were planted into nude mice to observe whether they could grow into new planted tumors in this kind of immunodeficiency animals.RESULTS: The fusion cells had weaker proliferative activity and clone abilities than their parental cells. When they were cultured, the counts of cells did not increase remarkably, nor could they grow into cell clones in culture medium. The fusion cells could not grow into new planted tumors after planted into nude mice. The stimulating abilities of the fusion cells on T lymphocytes' proliferations were remarkably increased than their parental dendritic cells.CONCLUSION: The SGC7901 gastric cancer cell-dendritic cell fusion vaccines have much weaker proliferative abilities than their parental cells, but they keep strong abilities to irritate the T lymphocytes and have no abilities to grow into new planted tumors in immunodeficiency animals. These are the biological basis for their antitumor biotherapies.

  9. 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.

  10. Dendritic cell targeted vaccines: Recent progresses and challenges.

    Science.gov (United States)

    Chen, Pengfei; Liu, Xinsheng; Sun, Yuefeng; Zhou, Peng; Wang, Yonglu; Zhang, Yongguang

    2016-03-01

    Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches.

  11. 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.

  12. 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.

  13. 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.

  14. Therapeutic Potential of Tolerogenic Dendritic Cells in IBD: From Animal Models to Clinical Application

    National Research Council Canada - National Science Library

    Cabezón, Raquel; Benítez-Ribas, Daniel

    2013-01-01

    ...) resulting in altered immune responses to harmless microorganisms. Dendritic cells (DCs) are sentinels of immunity, located in peripheral and lymphoid tissues, which are essential for homeostasis of T cell-dependent immune responses...

  15. Group 2 innate lymphoid cells license dendritic cells to potentiate memory TH2 cell responses.

    Science.gov (United States)

    Halim, Timotheus Y F; Hwang, You Yi; Scanlon, Seth T; Zaghouani, Habib; Garbi, Natalio; Fallon, Padraic G; McKenzie, Andrew N J

    2016-01-01

    Rapid activation of memory CD4(+) T helper 2 (TH2) cells during allergic inflammation requires their recruitment into the affected tissue. Here we demonstrate that group 2 innate lymphoid (ILC2) cells have a crucial role in memory TH2 cell responses, with targeted depletion of ILC2 cells profoundly impairing TH2 cell localization to the lungs and skin of sensitized mice after allergen re-challenge. ILC2-derived interleukin 13 (IL-13) is critical for eliciting production of the TH2 cell-attracting chemokine CCL17 by IRF4(+)CD11b(+)CD103(-) dendritic cells (DCs). Consequently, the sentinel function of DCs is contingent on ILC2 cells for the generation of an efficient memory TH2 cell response. These results elucidate a key innate mechanism in the regulation of the immune memory response to allergens.

  16. Molecular Mechanisms of Induction of Tolerant and Tolerogenic Intestinal Dendritic Cells in Mice.

    Science.gov (United States)

    Steimle, Alex; Frick, Julia-Stefanie

    2016-01-01

    How does the host manage to tolerate its own intestinal microbiota? A simple question leading to complicated answers. In order to maintain balanced immune responses in the intestine, the host immune system must tolerate commensal bacteria in the gut while it has to simultaneously keep the ability to fight pathogens and to clear infections. If this tender equilibrium is disturbed, severe chronic inflammatory reactions can result. Tolerogenic intestinal dendritic cells fulfil a crucial role in balancing immune responses and therefore creating homeostatic conditions and preventing from uncontrolled inflammation. Although several dendritic cell subsets have already been characterized to play a pivotal role in this process, less is known about definite molecular mechanisms of how intestinal dendritic cells are converted into tolerogenic ones. Here we review how gut commensal bacteria interact with intestinal dendritic cells and why this bacteria-host cell interaction is crucial for induction of dendritic cell tolerance in the intestine. Hereby, different commensal bacteria can have distinct effects on the phenotype of intestinal dendritic cells and these effects are mainly mediated by impacting toll-like receptor signalling in dendritic cells.

  17. Inhibitory effects of human immunodeficiency virus gp120 and Tat on CpG-A-induced inflammatory cytokines in plasmacytoid dendritic cells

    Institute of Scientific and Technical Information of China (English)

    Meixin Fang; Ning Xu; Xueting Shao; Jin Yang; Nanping Wu; Hangping Yao

    2012-01-01

    Plasmacytoid dendritic cells (pDCs),not only inhibit viral replication,but also play an essential role in linking the innate and adaptive immune system.In this study,we explored the effects of human immunodeficiency virus (HIV) gp120 and tat on CpG-A-induced inflammatory cytokines in pDCs.The results provided fundamental insights into HIV pathogenesis that may hold promise for preventative and even curative strategies,pDCs were isolated using blood DC antigen 4 (BDCA-4) DC isolation kit,and the purity was analyzed using BDCA-2 antibody by flow cytometry,pDCs and peripheral blood mononuclear cells (PBMCs) were stimulated by either CpG-A (5 μg/ml),gp120 (0.5 μg/ml),tat (0.5 μg/ml),or CpG-A treatment combined with gpl20 or tat.The production of type Ⅰ interferons (IFNs) and other inflammatory cytokines,including tumor necrosis factor-alpha (TNF-α),interlukine-6 (IL-6),and interferon-gammainducible protein-10 (IP-10) in the culture supernatant,was determined by enzyme-linked immunosorbent assay.The results showed that CpG-A induced high levels of type I IFNs and other inflammatory cytokines,including TNF-α,IL-6,and IP-10,in pDCs.Concomitant treatment with gp120 reduced the levels of IFN-α,IFN-β,TNF-α,IL-6,and IP-10 induced by CpG-A in pDCs by 79%,53%,60%,50%,and 34%,respectively,while tat suppressed them by 88%,66%,71%,64%,and 53%,respectively.Similar results were demonstrated in CpGA-treated PBMCs.In conclusion,gp120 and tat are effective inhibitors of the CpG-A-mediated induction of type I IFNs and other inflammatory cytokines from pDCs and PBMCs.

  18. Caspases regulate VAMP-8 expression and phagocytosis in dendritic cells.

    Science.gov (United States)

    Ho, Yong Hou Sunny; Cai, Deyu Tarika; Huang, Dachuan; Wang, Cheng Chun; Wong, Siew Heng

    2009-09-18

    During an inflammation and upon encountering pathogens, immature dendritic cells (DC) undergo a maturation process to become highly efficient in presenting antigens. This transition from immature to mature state is accompanied by various physiological, functional and morphological changes including reduction of caspase activity and inhibition of phagocytosis in the mature DC. Caspases are cysteine proteases which play essential roles in apoptosis, necrosis and inflammation. Here, we demonstrate that VAMP-8, (a SNARE protein of the early/late endosomes) which has been shown previously to inhibit phagocytosis in DC, is a substrate of caspases. Furthermore, we identified two putative conserved caspase recognition/cleavage sites on the VAMP-8 protein. Consistent with the up-regulation of VAMP-8 expression upon treatment with caspase inhibitor (CI), immature DC treated with CI exhibits lower phagocytosis activity. Thus, our results highlight the role of caspases in regulating VAMP-8 expression and subsequently phagocytosis during maturation of DC.

  19. Functional RNA delivery targeted to dendritic cells by synthetic nanoparticles.

    Science.gov (United States)

    McCullough, Kenneth C; Bassi, Isabelle; Démoulins, Thomas; Thomann-Harwood, Lisa J; Ruggli, Nicolas

    2012-09-01

    Dendritic cells (DCs) are essential to many aspects of immune defense development and regulation. They provide important targets for prophylactic and therapeutic delivery. While protein delivery has had considerable success, RNA delivery is still expanding. Delivering RNA molecules for RNAi has shown particular success and there are reports on successful delivery of mRNA. Central, therein, is the application of cationic entities. Following endocytosis of the delivery vehicle for the RNA, cationic entities should promote vesicular membrane perturbation, facilitating cytosolic release. The present review explains the diversity of DC function in immune response development and control. Promotion of delivered RNA cytosolic release is discussed, relating to immunoprophylactic and therapeutic potential, and DC endocytic machinery is reviewed, showing how DC endocytic pathways influence the handling of internalized material. The potential advantages for application of replicating RNA are presented and discussed, in consideration of their value and development in the near future.

  20. Differential Control of BST2 Restriction and Plasmacytoid Dendritic Cell Antiviral Response by Antagonists Encoded by HIV-1 Group M and O Strains.

    Science.gov (United States)

    Bego, Mariana G; Cong, Lijun; Mack, Katharina; Kirchhoff, Frank; Cohen, Éric A

    2016-11-15

    BST2/tetherin is a type I interferon (IFN-I)-stimulated host factor that restricts the release of HIV-1 by entrapping budding virions at the cell surface. This membrane-associated protein can also engage and activate the plasmacytoid dendritic cell (pDC)-specific immunoglobulin-like transcript 7 (ILT7) inhibitory receptor to downregulate the IFN-I response by pDCs. Pandemic HIV-1 group M uses Vpu (M-Vpu) to counteract the two BST2 isoforms (long and short) that are expressed in human cells. M-Vpu efficiently downregulates surface long BST2, while it displaces short BST2 molecules away from viral assembly sites. We recently found that this attribute is used by M-Vpu to activate the BST2/ILT7-dependent negative-feedback pathway and to suppress pDC IFN-I responses during sensing of infected cells. However, whether this property is conserved in endemic HIV-1 group O, which has evolved Nef (O-Nef) to counteract specifically the long BST2 isoform, remains unknown. In the present study, we validated that O-Nefs have the capacity to downregulate surface BST2 and enhance HIV-1 particle release although less efficiently than M-Vpu. In contrast to M-Vpu, O-Nef did not efficiently enhance viral spread in T cell culture or displace short BST2 from viral assembly sites to prevent its occlusion by tethered HIV-1 particles. Consequently, O-Nef impairs the ability of BST2 to activate negative ILT7 signaling to suppress the IFN-I response by pDC-containing peripheral blood mononuclear cells (PBMCs) during sensing of infected cells. These distinctive features of BST2 counteraction by O-Nefs may in part explain the limited spread of HIV-1 group O in the human population.

  1. A Model of Cytotoxic T Antitumor Activation Stimulated by Pulsed Dendritic Cells

    Science.gov (United States)

    Pennisi, Marzio; Pappalardo, Francesco; Chiacchio, Ferdinando; Motta, Santo

    2011-09-01

    We present a preliminary ODE model to sketch the immune response of cytotoxic T cells against cancer through the use of pulsed autologous dendritic cells. The model is partially based on data coming from experiments that are presently in progress in the wet lab of our collaborators, but it can be applied in principle to different tumors. To this end, we show the immune response of cytotoxic T cells stimulated by autologous dendritic cells for different cancers.

  2. Heat Shock Protein 96 Induces Maturation of Dendritic Cells

    Institute of Scientific and Technical Information of China (English)

    Chunxia Cao; Wei Yang; Yonglie Chu; Qingguang Liu; Liang Yu; Cheng'en Pan

    2006-01-01

    Objective: Heat shock protein (HSP) has the promiscuous abilities to chaperone and present a broad repertoire of tumor antigens to antigen presenting cells including DCs. In this report, we analyzed the modulation of immature DC by HSP 96 (gp96).Method: Murine bone marrow-derived DC was induced by GM-CSF plus IL-4, which aped the immunostimulatory effects of DC.Cocultured DC and gp96-peptide complexes (gp96-PC) or inactivated H22 cells, the expression of MHC class Ⅱ, CD40, CD80 was quantified by flow cytometry. The concentration of IL-12 and TNF- in culture supernatants were determined by ELISA.[51] Cr release assay was used to test specific cytotoxic T cell. Results: Our study demonstrated that the extent of DC maturation induced by gp96-PC, which was reflected in surface density of costimulatory and MHC Ⅱ molecules, was correlated with the secretion of IL-12 and with the T cellactivating potential in vitro. Conclusion: Heat shock protein 96 could be isolated and purified from H22 cells and could induce maturation of dendritic cell. Our findings might be relevance to the use of DC vaccine in therapy of human tumors.

  3. Polyelectrolyte coating of ferumoxytol nanoparticles for labeling of dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Celikkin, Nehar; Jakubcová, Lucie; Zenke, Martin [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstrasse 20, 52074 Aachen (Germany); Hoss, Mareike [Institute of Pathology, Electron Microscopy Facility, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen (Germany); Wong, John Erik, E-mail: John.Wong@avt.rwth-aachen.de [Chemical Process Engineering, RWTH Aachen University, Turmstrasse 46, 52056 Aachen (Germany); DWI – Leibniz Institute for Interactive Materials Research, Forckenbeckstrasse 50, Aachen (Germany); Hieronymus, Thomas, E-mail: thomas.hieronymus@rwth-aachen.de [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, RWTH Aachen University, Pauwelsstrasse 20, 52074 Aachen (Germany)

    2015-04-15

    Engineered magnetic nanoparticles (MNPs) are emerging to be used as cell tracers, drug delivery vehicles, and contrast agents for magnetic resonance imaging (MRI) for enhanced theragnostic applications in biomedicine. In vitro labeling of target cell populations with MNPs and their implantation into animal models and patients shows promising outcomes in monitoring successful cell engraftment, differentiation and migration by using MRI. Dendritic cells (DCs) are professional antigen-presenting cells that initiate adaptive immune responses. Thus, DCs have been the focus of cellular immunotherapy and are increasingly applied in clinical trials. Here, we addressed the coating of different polyelectrolytes (PE) around ferumoxytol particles using the layer-by-layer technique. The impact of PE-coated ferumoxytol particles for labeling of DCs and Flt3{sup +} DC progenitors was then investigated. The results from our studies revealed that PE-coated ferumoxytol particles can be readily employed for labeling of DC and DC progenitors and thus are potentially suitable as contrast agents for MRI tracking.

  4. Characterization of Interleukin-15-Transpresenting Dendritic Cells for Clinical Use

    Directory of Open Access Journals (Sweden)

    J. M. J. Van den Bergh

    2017-01-01

    Full Text Available Personalized dendritic cell- (DC- based vaccination has proven to be safe and effective as second-line therapy against various cancer types. In terms of overall survival, there is still room for improvement of DC-based therapies, including the development of more immunostimulatory DC vaccines. In this context, we redesigned our currently clinically used DC vaccine generation protocol to enable transpresentation of interleukin- (IL- 15 to IL-15Rβγ-expressing cells aiming at boosting the antitumor immune response. In this study, we demonstrate that upon electroporation with both IL-15 and IL-15Rα-encoding messenger RNA, mature DC become highly positive for surface IL-15, without influencing the expression of prototypic mature DC markers and with preservation of their cytokine-producing capacity and their migratory profile. Functionally, we show that IL-15-transpresenting DC are equal if not better inducers of T-cell proliferation and are superior in tumor antigen-specific T-cell activation compared with DC without IL-15 conditioning. In view of the clinical use of DC vaccines, we evidence with a time- and cost-effective manner that clinical grade DC can be safely engineered to transpresent IL-15, hereby gaining the ability to transfer the immune-stimulating IL-15 signal towards antitumor immune effector cells.

  5. Spatial distribution of excitatory synapses on the dendrites of ganglion cells in the mouse retina.

    Science.gov (United States)

    Chen, Yin-Peng; Chiao, Chuan-Chin

    2014-01-01

    Excitatory glutamatergic inputs from bipolar cells affect the physiological properties of ganglion cells in the mammalian retina. The spatial distribution of these excitatory synapses on the dendrites of retinal ganglion cells thus may shape their distinct functions. To visualize the spatial pattern of excitatory glutamatergic input into the ganglion cells in the mouse retina, particle-mediated gene transfer of plasmids expressing postsynaptic density 95-green fluorescent fusion protein (PSD95-GFP) was used to label the excitatory synapses. Despite wide variation in the size and morphology of the retinal ganglion cells, the expression of PSD95 puncta was found to follow two general rules. Firstly, the PSD95 puncta are regularly spaced, at 1-2 µm intervals, along the dendrites, whereby the presence of an excitatory synapse creates an exclusion zone that rules out the presence of other glutamatergic synaptic inputs. Secondly, the spatial distribution of PSD95 puncta on the dendrites of diverse retinal ganglion cells are similar in that the number of excitatory synapses appears to be less on primary dendrites and to increase to a plateau on higher branch order dendrites. These observations suggest that synaptogenesis is spatially regulated along the dendritic segments and that the number of synaptic contacts is relatively constant beyond the primary dendrites. Interestingly, we also found that the linear puncta density is slightly higher in large cells than in small cells. This may suggest that retinal ganglion cells with a large dendritic field tend to show an increased connectivity of excitatory synapses that makes up for their reduced dendrite density. Mapping the spatial distribution pattern of the excitatory synapses on retinal ganglion cells thus provides explicit structural information that is essential for our understanding of how excitatory glutamatergic inputs shape neuronal responses.

  6. Dendritic Arborization Patterns of Small Juxtaglomerular Cell Subtypes within the Rodent Olfactory Bulb

    Science.gov (United States)

    Bywalez, Wolfgang G.; Ona-Jodar, Tiffany; Lukas, Michael; Ninkovic, Jovica; Egger, Veronica

    2017-01-01

    Within the glomerular layer of the rodent olfactory bulb, numerous subtypes of local interneurons contribute to early processing of incoming sensory information. Here we have investigated dopaminergic and other small local juxtaglomerular cells in rats and mice and characterized their dendritic arborization pattern with respect to individual glomeruli by fluorescent labeling via patching and reconstruction of dendrites and glomerular contours from two-photon imaging data. Dopaminergic neurons were identified in a transgenic mouse line where the expression of dopamine transporter (DAT) was labeled with GFP. Among the DAT+ cells we found a small short-axon cell (SAC) subtype featuring hitherto undescribed dendritic specializations. These densely ramifying structures clasped mostly around somata of other juxtaglomerular neurons, which were also small, non-dopaminergic and to a large extent non-GABAergic. Clasping SACs were observed also in wild-type mice and juvenile rats. In DAT+ SAC dendrites, single backpropagating action potentials evoked robust calcium entry throughout both clasping and non-clasping compartments. Besides clasping SACs, most other small neurons either corresponded to the classical periglomerular cell type (PGCs), which was never DAT+, or were undersized cells with a small dendritic tree and low excitability. Aside from the presence of clasps in SAC dendrites, many descriptors of dendritic morphology such as the number of dendrites and the extent of branching were not significantly different between clasping SACs and PGCs. However, a detailed morphometric analysis in relation to glomerular contours revealed that the dendrites of clasping SACs arborized mostly in the juxtaglomerular space and never entered more than one glomerulus (if at all), whereas most PGC dendrites were restricted to their parent glomerulus, similar to the apical tufts of mitral cells. These complementary arborization patterns might underlie a highly complementary functional

  7. Dendritic differentiation of cerebellar Purkinje cells is promoted by ryanodine receptors expressed by Purkinje and granule cells.

    Science.gov (United States)

    Ohashi, Ryo; Sakata, Shin-ichi; Naito, Asami; Hirashima, Naohide; Tanaka, Masahiko

    2014-04-01

    Cerebellar Purkinje cells have the most elaborate dendritic trees among neurons in the brain. We examined the roles of ryanodine receptor (RyR), an intracellular Ca(2+) release channel, in the dendrite formation of Purkinje cells using cerebellar cell cultures. In the cerebellum, Purkinje cells express RyR1 and RyR2, whereas granule cells express RyR2. When ryanodine (10 µM), a blocker of RyR, was added to the culture medium, the elongation and branching of Purkinje cell dendrites were markedly inhibited. When we transferred small interfering RNA (siRNA) against RyR1 into Purkinje cells using single-cell electroporation, dendritic branching but not elongation of the electroporated Purkinje cells was inhibited. On the other hand, transfection of RyR2 siRNA into granule cells also inhibited dendritic branching of Purkinje cells. Furthermore, ryanodine reduced the levels of brain-derived neurotrophic factor (BDNF) in the culture medium. The ryanodine-induced inhibition of dendritic differentiation was partially rescued when BDNF was exogenously added to the culture medium in addition to ryanodine. Overall, these results suggest that RyRs expressed by both Purkinje and granule cells play important roles in promoting the dendritic differentiation of Purkinje cells and that RyR2 expressed by granule cells is involved in the secretion of BDNF from granule cells.

  8. DMPD: Proximal effects of Toll-like receptor activation in dendritic cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17142025 Proximal effects of Toll-like receptor activation in dendritic cells. Watt...) (.svg) (.html) (.csml) Show Proximal effects of Toll-like receptor activation in dendritic cells. PubmedID... 17142025 Title Proximal effects of Toll-like receptor activation in dendritic ce

  9. Impact of Dendritic Size and Dendritic Topology on Burst Firing in Pyramidal Cells

    NARCIS (Netherlands)

    van Elburg, Ronald A. J.; van Ooyen, Arjen

    2010-01-01

    Neurons display a wide range of intrinsic firing patterns. A particularly relevant pattern for neuronal signaling and synaptic plasticity is burst firing, the generation of clusters of action potentials with short interspike intervals. Besides ion-channel composition, dendritic morphology appears to

  10. Novel immunomodulatory effects of adiponectin on dendritic cell functions.

    Science.gov (United States)

    Tsang, Julia Yuen Shan; Li, Daxu; Ho, Derek; Peng, Jiao; Xu, Aimin; Lamb, Jonathan; Chen, Yan; Tam, Paul Kwong Hang

    2011-05-01

    Adiponectin (ADN) is an adipocytokine with anti-inflammatory properties. Although it has been reported that ADN can inhibit the immunostimulatory function of monocytes and macrophages, little is known of its effect on dendritic cells (DC). Recent data suggest that ADN can regulate immune responses. DCs are uniquely specialised antigen presenting cells that play a central role in the initiation of immunity and tolerance. In this study, we have investigated the immuno- modulatory effects of ADN on DC functions. We found that ADN has only moderate effect on the differentiation of murine bone marrow (BM) derived DCs but altered the phenotype of DCs. The expression of major histocompatibilty complex class II (MHCII), CD80 and CD86 on ADN conditioned DCs (ADN-DCs) was lower than that on untreated cells. The production of IL-12p40 was also suppressed in ADN-DCs. Interestingly, ADN treated DCs showed an increase in the expression of the inhibitory molecule, programmed death-1 ligand (PDL-1) compared to untreated cells. In vitro co-culture of ADN-DCs with allogeneic T cells led to a decrease in T cell proliferation and reduction of IL-2 production. Concomitant with that, a higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) was detected in co-cultures of T cells and ADN-DCs. Blocking PD-1/PDL-1 pathway could partially restore T cell function. These findings suggest that the immunomodulatory effect of ADN on immune responses could be at least partially be mediated by its ability to alter DC function. The PD-1/PDL-1 pathway and the enhancement of Treg expansion are implicated in the immunomodulatory mechanisms.

  11. Tumor-derived death receptor 6 modulates dendritic cell development.

    Science.gov (United States)

    DeRosa, David C; Ryan, Paul J; Okragly, Angela; Witcher, Derrick R; Benschop, Robert J

    2008-06-01

    Studies in murine models of cancer as well as in cancer patients have demonstrated that the immune response to cancer is often compromised. This paradigm is viewed as one of the major mechanisms of tumor escape. Many therapies focus on employing the professional antigen presenting dendritic cells (DC) as a strategy to overcome immune inhibition in cancer patients. Death receptor 6 (DR6) is an orphan member of the tumor necrosis factor receptor superfamily (TNFRSF21). It is overexpressed on many tumor cells and DR6(-/-) mice display altered immunity. We investigated whether DR6 plays a role in tumorigenesis by negatively affecting the generation of anti-tumor activity. We show that DR6 is uniquely cleaved from the cell surface of tumor cell lines by the membrane-associated matrix metalloproteinase (MMP)-14, which is often overexpressed on tumor cells and is associated with malignancy. We also demonstrate that >50% of monocytes differentiating into DC die when the extracellular domain of DR6 is present. In addition, DR6 affects the cell surface phenotype of the resulting immature DC and changes their cytokine production upon stimulation with LPS/IFN-gamma. The effects of DR6 are mostly amended when these immature DC are matured with IL-1beta/TNF-alpha, as measured by cell surface phenotype and their ability to present antigen. These results implicate MMP-14 and DR6 as a mechanism tumor cells can employ to actively escape detection by the immune system by affecting the generation of antigen presenting cells.

  12. SK2 channel modulation contributes to compartment-specific dendritic plasticity in cerebellar Purkinje cells.

    Science.gov (United States)

    Ohtsuki, Gen; Piochon, Claire; Adelman, John P; Hansel, Christian

    2012-07-12

    Small-conductance Ca(2+)-activated K(+) channels (SK channels) modulate excitability and curtail excitatory postsynaptic potentials (EPSPs) in neuronal dendrites. Here, we demonstrate long-lasting plasticity of intrinsic excitability (IE) in dendrites that results from changes in the gain of this regulatory mechanism. Using dendritic patch-clamp recordings from rat cerebellar Purkinje cells, we find that somatic depolarization or parallel fiber (PF) burst stimulation induce long-term amplification of synaptic responses to climbing fiber (CF) or PF stimulation and enhance the amplitude of passively propagated sodium spikes. Dendritic plasticity is mimicked and occluded by the SK channel blocker apamin and is absent in Purkinje cells from SK2 null mice. Triple-patch recordings from two dendritic sites and the soma and confocal calcium imaging studies show that local stimulation limits dendritic plasticity to the activated compartment of the dendrite. This plasticity mechanism allows Purkinje cells to adjust the SK2-mediated control of dendritic excitability in an activity-dependent manner.

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

    OpenAIRE

    Buschow, S.I.

    2006-01-01

    Many cell types, including dendritic cells (DC) and B cells, secrete small vesicles called exosomes. Exosomes from immune cells are thought to have immuno-regulatory functions but their precise role remains unresolved. The aim of the studies presented in this thesis was to get more insight into the factors that determine exosome formation, composition and secretion as well as to learn more about their physiological relevance. Exosomes are equivalent to Luminal Vesicles (LV) of Multi Vesicular...

  14. Candida albicans mannoprotein influences the biological function of dendritic cells.

    Science.gov (United States)

    Pietrella, Donatella; Bistoni, Giovanni; Corbucci, Cristina; Perito, Stefano; Vecchiarelli, Anna

    2006-04-01

    Cell wall components of fungi involved in induction of host immune response are predominantly proteins and glycoproteins, the latter being mainly mannoproteins (MP). In this study we analyse the interaction of the MP from Candida albicans (MP65) with dendritic cells (DC) and demonstrate that MP65 stimulates DC and induces the release of TNF-alpha, IL-6 and the activation of IL-12 gene, with maximal value 6 h post treatment. MP65 induces DC maturation by increasing costimulatory molecules and decreasing CD14 and FcgammaR molecule expression. The latter effect is partly mediated by toll-like receptor 2 (TLR2) and TLR4, and the MyD88-dependent pathway is involved in the process. MP65 enables DC to activate T cell response, its protein core is essential for induction of T cell activation, while its glycosylated portion primarily promotes cytokine production. The mechanisms involved in induction of protective response against C. albicans could be mediated by the MP65 antigen, suggesting that MP65 may be a suitable candidate vaccine.

  15. Role of mucosal dendritic cells in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Jan Hendrik Niess

    2008-01-01

    The gastrointestinal innate and adaptive immune system continuously faces the challenge of potent stimuli from the commensal microflora and food constituents.These local immune responses require a tight control,the outcome of which is in most cases the induction of tolerance.Local T cell immunity is an important compartment of the specific intestinal immune system.T cell reactivity is programmed during the initial stage of its activation by professional presenting cells.Mucosal dendritic cells(DCs)are assumed to play key roles in regulating immune responses in the antigen-rich gastrointestinal environment.Mucosal DCs are a heterogeneous population that can either initiate(innate and adaptive)immune responses,or control intestinal inflammation and maintain tolerance.Defects in this regulation are supposed to lead to the two major forms of inflammatory bowel disease(IBD),Crohn's disease(CD)and ulcerative colitis(UC).This review will discuss the emerging role of mucosal DCs in regulating intestinal inflammation and immune responses.(C)2008 The WJG Press.All rights reserved.

  16. Targeting Dendritic Cell Function during Systemic Autoimmunity to Restore Tolerance

    Directory of Open Access Journals (Sweden)

    Juan P. Mackern-Oberti

    2014-09-01

    Full Text Available Systemic autoimmune diseases can damage nearly every tissue or cell type of the body. Although a great deal of progress has been made in understanding the pathogenesis of autoimmune diseases, current therapies have not been improved, remain unspecific and are associated with significant side effects. Because dendritic cells (DCs play a major role in promoting immune tolerance against self-antigens (self-Ags, current efforts are focusing at generating new therapies based on the transfer of tolerogenic DCs (tolDCs during autoimmunity. However, the feasibility of this approach during systemic autoimmunity has yet to be evaluated. TolDCs may ameliorate autoimmunity mainly by restoring T cell tolerance and, thus, indirectly modulating autoantibody development. In vitro induction of tolDCs loaded with immunodominant self-Ags and subsequent cell transfer to patients would be a specific new therapy that will avoid systemic immunosuppression. Herein, we review recent approaches evaluating the potential of tolDCs for the treatment of systemic autoimmune disorders.

  17. Dendritic Cells as Pharmacological Tools for Cancer Immunotherapy.

    Science.gov (United States)

    Anguille, Sébastien; Smits, Evelien L; Bryant, Christian; Van Acker, Heleen H; Goossens, Herman; Lion, Eva; Fromm, Phillip D; Hart, Derek N; Van Tendeloo, Viggo F; Berneman, Zwi N

    2015-10-01

    Although the earliest—rudimentary—attempts at exploiting the immune system for cancer therapy can be traced back to the late 18th Century, it was not until the past decade that cancer immunotherapeutics have truly entered mainstream clinical practice. Given their potential to stimulate both adaptive and innate antitumor immune responses, dendritic cells (DCs) have come under intense scrutiny in recent years as pharmacological tools for cancer immunotherapy. Conceptually, the clinical effectiveness of this form of active immunotherapy relies on the completion of three critical steps: 1) the DCs used as immunotherapeutic vehicles must properly activate the antitumor immune effector cells of the host, 2) these immune effector cells must be receptive to stimulation by the DCs and be competent to mediate their antitumor effects, which 3) requires overcoming the various immune-inhibitory mechanisms used by the tumor cells. In this review, following a brief overview of the pivotal milestones in the history of cancer immunotherapy, we will introduce the reader to the basic immunobiological and pharmacological principles of active cancer immunotherapy using DCs. We will then discuss how current research is trying to define the optimal parameters for each of the above steps to realize the full clinical potential of DC therapeutics. Given its high suitability for immune interventions, acute myeloid leukemia was chosen here to showcase the latest research trends driving the field of DC-based cancer immunotherapy.

  18. Exploration Of The Dendritic Cell Algorithm Using The Duration Calculus

    CERN Document Server

    Gu, Feng; Aickelin, Uwe

    2010-01-01

    As one of the newest members in Artificial Immune Systems (AIS), the Dendritic Cell Algorithm (DCA) has been applied to a range of problems. These applications mainly belong to the field of anomaly detection. However, real-time detection, a new challenge to anomaly detection, requires improvement on the real-time capability of the DCA. To assess such capability, formal methods in the research of rea-time systems can be employed. The findings of the assessment can provide guideline for the future development of the algorithm. Therefore, in this paper we use an interval logic based method, named the Duration Calculus (DC), to specify a simplified single-cell model of the DCA. Based on the DC specifications with further induction, we find that each individual cell in the DCA can perform its function as a detector in real-time. Since the DCA can be seen as many such cells operating in parallel, it is potentially capable of performing real-time detection. However, the analysis process of the standard DCA constrict...

  19. Regulatory multitasking of tolerogenic dendritic cells – lessons taken from Vitamin D3-treated tolerogenic dendritic cells

    Directory of Open Access Journals (Sweden)

    Tatjana eNikolic

    2013-05-01

    Full Text Available Tolerogenic dendritic cells (DCs work through silencing of differentiated antigen-specific T cells, activation and expansion of naturally occurring T regulatory cells (Tregs, transfer of regulatory properties to T cells and the differentiation of naïve T cells into Tregs. Due to an operational definition based on T cell activation assays, the identity of tolerogenic DCs has been a matter of debate and it need not represent a specialized DC subset. Human tolerogenic DCs generated in vitro using inhibitory cytokines, growth factors, natural immunomodulators or genetic manipulation have been effective and several of these tolerogenic DCs are currently being tested for clinical use. Ex vivo generated tolerogenic DCs reduce activation of naïve T cells using various means, promote a variety of regulatory T cells and most importantly, frequently show stable inhibitory phenotypes upon repetitive maturation with inflammatory factors. Yet, tolerogenic DCs differ with respect to the phenotype or the number of regulatory mechanisms they employ to modulate the immune system. In our experience, tolerogenic DCs generated using the biologically active form of vitamin D (VD3-DCs, alone or combined with dexamethasone are proficient in their immunoregulatory functions. These tolerogenic DCs show a stable maturation-resistant semi-mature phenotype with low expression of activating co-stimulatory molecules, no production of the IL-12 family of cytokines and high expression of inhibitory molecules and IL-10. VD3-DCs induce increased apoptosis of effector T cells and induce antigen-specific regulatory T cells, which work through linked suppression ensuring infectious tolerance. Lessons learned on VD3-DCs help understanding the contribution of different pattern recognition receptors (PRRs and secondary signals to the tolerogenic function and how a cross-talk between DCs and T cells translates into immune regulation.

  20. Structured Dendritic Inhibition Supports Branch-Selective Integration in CA1 Pyramidal Cells.

    Science.gov (United States)

    Bloss, Erik B; Cembrowski, Mark S; Karsh, Bill; Colonell, Jennifer; Fetter, Richard D; Spruston, Nelson

    2016-03-02

    Neuronal circuit function is governed by precise patterns of connectivity between specialized groups of neurons. The diversity of GABAergic interneurons is a hallmark of cortical circuits, yet little is known about their targeting to individual postsynaptic dendrites. We examined synaptic connectivity between molecularly defined inhibitory interneurons and CA1 pyramidal cell dendrites using correlative light-electron microscopy and large-volume array tomography. We show that interneurons can be highly selective in their connectivity to specific dendritic branch types and, furthermore, exhibit precisely targeted connectivity to the origin or end of individual branches. Computational simulations indicate that the observed subcellular targeting enables control over the nonlinear integration of synaptic input or the initiation and backpropagation of action potentials in a branch-selective manner. Our results demonstrate that connectivity between interneurons and pyramidal cell dendrites is more precise and spatially segregated than previously appreciated, which may be a critical determinant of how inhibition shapes dendritic computation.

  1. Mammal-derived respiratory lipocalin allergens do not exhibit dendritic cell-activating capacity.

    Science.gov (United States)

    Parviainen, S; Kinnunen, T; Rytkönen-Nissinen, M; Nieminen, A; Liukko, A; Virtanen, T

    2013-03-01

    Most mammal-derived respiratory allergens belong to the lipocalin family of proteins. Determinants of their allergenic capacity are still unknown. Innate immune cells, in particular dendritic cells, have been shown to be involved in the allergenicity of some proteins. As recognition by dendritic cells is one of the few plausible mechanisms for the allergenicity of proteins, we wanted to investigate their role in the allergenicity of lipocalin allergens. Therefore, we first incubated human monocyte-derived dendritic cells with immunologically functional recombinant allergens mouse Mus m 1, dog Can f 1 and 2, cow Bos d 2, horse Equ c 1 and natural Bos d 2. Then, the surface marker expression and cytokine production of dendritic cells and their capacity to promote T cell proliferation and Th2 immune deviation in naïve CD4(+) T cells were examined in vitro. We found that near to endotoxin-free lipocalin allergens had no effect on the activation, allostimulatory capacity or cytokine production of dendritic cells. The dendritic cells could not induce immune deviation in naïve CD4(+) T cells. In contrast, lipopolysaccharide activated the dendritic cells efficiently. However, lipocalin allergens were not able to modify the lipopolysaccharide-induced responses. We conclude that an important group of mammal-derived respiratory allergens, lipocalins, appear not to be able to activate dendritic cells, a major component involved in the allergenicity of some proteins. It is conceivable that this incapacity of lipocalin allergens to arouse innate immunity may be associated with their poor capacity to induce a strong T cell response, verified in several studies.

  2. Modulation of Dendritic Cell Responses by Parasites: A Common Strategy to Survive

    Directory of Open Access Journals (Sweden)

    César A. Terrazas

    2010-01-01

    Full Text Available Parasitic infections are one of the most important causes of morbidity and mortality in our planet and the immune responses triggered by these organisms are critical to determine their outcome. Dendritic cells are key elements for the development of immunity against parasites; they control the responses required to eliminate these pathogens while maintaining host homeostasis. However, there is evidence showing that parasites can influence and regulate dendritic cell function in order to promote a more permissive environment for their survival. In this review we will focus on the strategies protozoan and helminth parasites have developed to interfere with dendritic cell activities as well as in the possible mechanisms involved.

  3. Dendritic Cells under Hypoxia: How Oxygen Shortage Affects the Linkage between Innate and Adaptive Immunity.

    Science.gov (United States)

    Winning, Sandra; Fandrey, Joachim

    2016-01-01

    Dendritic cells (DCs) are considered as one of the main regulators of immune responses. They collect antigens, process them, and present typical antigenic structures to lymphocytes, thereby inducing an adaptive immune response. All these processes take place under conditions of oxygen shortage (hypoxia) which is often not considered in experimental settings. This review highlights how deeply hypoxia modulates human as well as mouse immature and mature dendritic cell functions. It tries to link in vitro results to actual in vivo studies and outlines how hypoxia-mediated shaping of dendritic cells affects the activation of (innate) immunity.

  4. Dendritic Cells under Hypoxia: How Oxygen Shortage Affects the Linkage between Innate and Adaptive Immunity

    Directory of Open Access Journals (Sweden)

    Sandra Winning

    2016-01-01

    Full Text Available Dendritic cells (DCs are considered as one of the main regulators of immune responses. They collect antigens, process them, and present typical antigenic structures to lymphocytes, thereby inducing an adaptive immune response. All these processes take place under conditions of oxygen shortage (hypoxia which is often not considered in experimental settings. This review highlights how deeply hypoxia modulates human as well as mouse immature and mature dendritic cell functions. It tries to link in vitro results to actual in vivo studies and outlines how hypoxia-mediated shaping of dendritic cells affects the activation of (innate immunity.

  5. Effects of inactivated porcine epidemic diarrhea virus on porcine monocyte-derived dendritic cells and intestinal dendritic cells.

    Science.gov (United States)

    Gao, Qi; Zhao, Shanshan; Qin, Tao; Yin, Yinyan; Yu, Qinghua; Yang, Qian

    2016-06-01

    Porcine epidemic diarrhea (PED) is a serious infection in neonatal piglets. As the causative agent of PED, porcine epidemic diarrhea virus (PEDV) results in acute diarrhea and dehydration with high mortality rates in swine. Dendritic cells (DCs) are highly effective antigen-presenting cells to uptake and present viral antigens to T cells, which then initiate a distinct immune response. In this study, our results show that the expression of Mo-DCs surface markers such as SWC3a(+)CD1a(+), SWC3a(+)CD80/86(+) and SWC3a(+)SLA-II-DR(+) is increased after incubation with UV-PEDV for 24h. Mo-DCs incubated with UV-PEDV produce higher levels of IL-12 and INF-γ compared to mock-infected Mo-DCs. Interactions between Mo-DCs and UV-PEDV significantly stimulate T-cell proliferation in vitro. Consistent with these results, there is an enhancement in the ability of porcine intestinal DCs to activate T-cell proliferation in vivo. We conclude that UV-PEDV may be a useful and safe vaccine to trigger adaptive immunity.

  6. Dendritic cell function in vivo during the steady state: a role in peripheral tolerance.

    Science.gov (United States)

    Steinman, Ralph M; Hawiger, Daniel; Liu, Kang; Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Iyoda, Tomonori; Ravetch, Jeffrey; Dhodapkar, Madhav; Inaba, Kayo; Nussenzweig, Michel

    2003-04-01

    The avoidance of autoimmunity requires mechanisms to actively silence or tolerize self reactive T cells in the periphery. During infection, dendritic cells are not only capturing microbial antigens, but also are processing self antigens from dying cells as well as innocuous environmental proteins. Since the dendritic cells are maturing in response to microbial and other stimuli, peptides will be presented from both noxious and innocuous antigens. Therefore it would be valuable to have mechanisms whereby dendritic cells, prior to infection, establish tolerance to those self and environmental antigens that can be processed upon pathogen encounter. In the steady state, prior to acute infection and inflammation, dendritic cells are in an immature state and not fully differentiated to carry out their known roles as inducers of immunity. These immature cells are not inactive, however. They continuously circulate through tissues and into lymphoid organs, capturing self antigens as well as innocuous environmental proteins. Recent experiments have provided direct evidence that antigen-loaded immature dendritic in vivo silence T cells either by deleting them or by expanding regulatory T cells. In this way, it is proposed that the immune system overcomes at least some of the risk of developing autoimmunity and chronic inflammation. It is proposed that dendritic cells play a major role in defining immunologic self, not only centrally in the thymus but also in the periphery.

  7. Regional Regulation of Purkinje Cell Dendritic Spines by Integrins and Eph/Ephrins.

    Science.gov (United States)

    Heintz, Tristan G; Eva, Richard; Fawcett, James W

    2016-01-01

    Climbing fibres and parallel fibres compete for dendritic space on Purkinje cells in the cerebellum. Normally, climbing fibres populate the proximal dendrites, where they suppress the multiple small spines typical of parallel fibres, leading to their replacement by the few large spines that contact climbing fibres. Previous work has shown that ephrins acting via EphA4 are a signal for this change in spine type and density. We have used an in vitro culture model in which to investigate the ephrin effect on Purkinje cell dendritic spines and the role of integrins in these changes. We found that integrins α3, α5 and β4 are present in many of the dendritic spines of cultured Purkinje cells. pFAK, the main downstream signalling molecule from integrins, has a similar distribution, although the intenstity of pFAK staining and the percentage of pFAK+ spines was consistently higher in the proximal dendrites. Activating integrins with Mg2+ led to an increase in the intensity of pFAK staining and an increase in the proportion of pFAK+ spines in both the proximal and distal dendrites, but no change in spine length, density or morphology. Blocking integrin binding with an RGD-containing peptide led to a reduction in spine length, with more stubby spines on both proximal and distal dendrites. Treatment of the cultures with ephrinA3-Fc chimera suppressed dendritic spines specifically on the proximal dendrites and there was also a decrease of pFAK in spines on this domain. This effect was blocked by simultaneous activation of integrins with Mn2+. We conclude that Eph/ephrin signaling regulates proximal dendritic spines in Purkinje cells by inactivating integrin downstream signalling.

  8. Spatial modelling of brief and long interactions between T cells and dendritic cells.

    Science.gov (United States)

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2007-06-01

    In the early phases of an immune response, T cells of appropriate antigen specificity become activated by antigen-presenting cells in secondary lymphoid organs. Two-photon microscopy imaging experiments have shown that this stimulation occurs in distinct stages during which T cells exhibit different motilities and interactions with dendritic cells (DCs). In this paper, we utilize the Cellular Potts Model, a model formalism that takes cell shapes and cellular interactions explicitly into account, to simulate the dynamics of, and interactions between, T cells and DCs in the lymph node paracortex. Our three-dimensional simulations suggest that the initial decrease in T-cell motility after antigen appearance is due to "stop signals" transmitted by activated DCs to T cells. The long-lived interactions that occur at a later stage can only be explained by the presence of both stop signals and a high adhesion between specific T cells and antigen-bearing DCs. Furthermore, our results indicate that long-lasting contacts with T cells are promoted when DCs retract dendrites that detect a specific contact at lower velocities than other dendrites. Finally, by performing long simulations (after prior fitting to short time scale data) we are able to provide an estimate of the average contact duration between T cells and DCs.

  9. DMPD: RAPping production of type I interferon in pDCs through mTOR. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18800159 RAPping production of type I interferon in pDCs through mTOR. Costa-Mattio...li M, Sonenberg N. Nat Immunol. 2008 Oct;9(10):1097-9. (.png) (.svg) (.html) (.csml) Show RAPping production... of type I interferon in pDCs through mTOR. PubmedID 18800159 Title RAPping production of type I interferon

  10. Dendritic cells a double-edge sword in autoimmune responses

    Directory of Open Access Journals (Sweden)

    Giada eAmodio

    2012-08-01

    Full Text Available Dendritic cells (DC are antigen-presenting cells that play a pivotal role in regulating innate and adaptive immune responses. In autoimmunity, DC act as a double-edged sword since on one hand they initiate adaptive self-reactive responses and on the other they play a pivotal role in promoting and maintaining tolerance. Thus, DC are the most important cells in either triggering self-specific responses or in negatively regulating auto-reactive responses. DC in the steady state or specialized subsets of DC, named tolerogenic DC, are involved in the latter function. Clinical and experimental evidence indicate that prolonged presentation of self-antigens by DC is crucial for the development of destructive autoimmune diseases, and defects in tolerogenic DC functions contribute to eradication of self-tolerance. In recent years, DC have emerged as therapeutic targets for limiting their immunogenicity against self-antigens, while tolerogenic DC have been conceived as therapeutic tools to restore tolerance. The purpose of this review is to give a general overview of the current knowledge on the pathogenic role of DC in patients affected by autoimmune diseases. In addition, the protective role of tolerogenic DC will be addressed. The currently applied strategies to block immune activation or to exploit the tolerogenic potential of DC will be discussed.

  11. GM-CSF alters dendritic cells in autoimmune diseases.

    Science.gov (United States)

    Li, Bao-Zhu; Ye, Qian-Ling; Xu, Wang-Dong; Li, Jie-Hua; Ye, Dong-Qing; Xu, Yuekang

    2013-11-01

    Autoimmune diseases arise from an inappropriate immune response against self components, including macromolecules, cells, tissues, organs etc. They are often triggered or accompanied by inflammation, during which the levels of granulocyte macrophage colony-stimulating factor (GM-CSF) are elevated. GM-CSF is an inflammatory cytokine that has profound impact on the differentiation of immune system cells of myeloid lineage, especially dendritic cells (DCs) that play critical roles in immune initiation and tolerance, and is involved in the pathogenesis of autoimmune diseases. Although GM-CSF was discovered decades ago, recent studies with some new findings have shed an interesting light on the old hematopoietic growth factor. In the inflammatory autoimmune diseases, GM-CSF redirects the normal developmental pathway of DCs, conditions their antigen presentation capacities and endows them with unique cytokine signatures to affect autoimmune responses. Here we review the latest advances in the field, with the aim of demonstrating the effects of GM-CSF on DCs and their influences on autoimmune diseases. The summarized knowledge will help to design DC-based strategies for the treatment of autoimmune diseases.

  12. Vaginal epithelial dendritic cells renew from bone marrow precursors.

    Science.gov (United States)

    Iijima, Norifumi; Linehan, Melissa M; Saeland, Sem; Iwasaki, Akiko

    2007-11-27

    Dendritic cells (DCs) represent key professional antigen-presenting cells capable of initiating primary immune responses. A specialized subset of DCs, the Langerhans cells (LCs), are located in the stratified squamous epithelial layer of the skin and within the mucosal epithelial lining of the vaginal and oral cavities. The vaginal mucosa undergoes cyclic changes under the control of sex hormones, and the renewal characteristics of the vaginal epithelial DCs (VEDCs) remain unknown. Here, we examined the origin of VEDCs. In contrast to the skin epidermal LCs, the DCs in the epithelium of the vagina were found to be repopulated mainly by nonmonocyte bone-marrow-derived precursors, with a half-life of 13 days under steady-state conditions. Upon infection with HSV-2, the Gr-1(hi) monocytes were found to give rise to VEDCs. Furthermore, flow cytometric analysis of the VEDCs revealed the presence of at least three distinct populations, namely, CD11b(+)F4/80(hi), CD11b(+)F4/80(int), and CD11b(-)F4/80(-). Importantly, these VEDC populations expressed CD207 at low levels and had a constitutively more activated phenotype compared with the skin LCs. Collectively, our results revealed mucosa-specific features of the VEDCs with respect to their phenotype, activation status, and homeostatic renewal potential.

  13. Loss of Gadkin Affects Dendritic Cell Migration In Vitro.

    Directory of Open Access Journals (Sweden)

    Hannah Schachtner

    Full Text Available Migration is crucial for the function of dendritic cells (DCs, which act as outposts of the immune system. Upon detection of pathogens, skin- and mucosa-resident DCs migrate to secondary lymphoid organs where they activate T cells. DC motility relies critically on the actin cytoskeleton, which is regulated by the actin-related protein 2/3 (ARP2/3 complex, a nucleator of branched actin networks. Consequently, loss of ARP2/3 stimulators and upstream Rho family GTPases dramatically impairs DC migration. However, nothing is known yet about the relevance of ARP2/3 inhibitors for DC migration. We previously demonstrated that the AP-1-associated adaptor protein Gadkin inhibits ARP2/3 by sequestering it on intracellular vesicles. Consistent with a role of Gadkin in DC physiology, we here report Gadkin expression in bone marrow-derived DCs and show that its protein level and posttranslational modification are regulated upon LPS-induced DC maturation. DCs derived from Gadkin-deficient mice were normal with regards to differentiation and maturation, but displayed increased actin polymerization. While the actin-dependent processes of macropinocytosis and cell spreading were not affected, loss of Gadkin significantly impaired DC migration in vitro, however, in vivo DC migration was unperturbed suggesting the presence of compensatory mechanisms.

  14. Synthetic and biogenic magnetite nanoparticles for tracking of stem cells and dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Sebastian [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Fernandes, Fabiana [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Department of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Sanroman, Laura [Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen University Medical School, Pauwelsstrasse 30, 52074 Aachen (Germany); Helmholtz Institute for Biomedical Engineering, Department of Cell Biology, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Hodenius, Michael [Institute for Biomedical Engineering and Helmholtz Institute for Biomedical Engineering, Department of Applied Medical Engineering, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Lang, Claus [Department of Microbiology, Ludwig-Maximillians-University of Munich, Maria-Ward-Str. 1a, 80638 Munich (Germany); Himmelreich, Uwe [In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Gleueler Str. 50, 50931 Cologne (Germany); Biomedical NMR Unit, MoSAIC, Faculty of Medicine, KU Leuven, Onderwijs en Navorsing 1, bus 505, 3000 Leuven (Belgium); Schmitz-Rode, Thomas [Institute for Biomedical Engineering and Helmholtz Institute for Biomedical Engineering, Department of Applied Medical Engineering, RWTH Aachen, Pauwelsstrasse 20, 52074 Aachen (Germany); Schueler, Dirk [Department of Microbiology, Ludwig-Maximillians-University of Munich, Maria-Ward-Str. 1a, 80638 Munich (Germany); Hoehn, Mathias [In-vivo-NMR-Laboratory, Max-Planck-Institute for Neurological Research, Gleueler Str. 50, 50931 Cologne (Germany)] (and others)

    2009-05-15

    Accurate delivery of cells to target organs is critical for success of cell-based therapies with stem cells or immune cells such as antigen-presenting dendritic cells (DC). Labeling with contrast agents before implantation provides a powerful means for monitoring cellular migration using magnetic resonance imaging (MRI). In this study, we investigated the uptake of fully synthesized or bacterial magnetic nanoparticles (MNPs) into hematopoietic Flt3{sup +} stem cells and DC from mouse bone marrow. We show that (i) uptake of both synthetic and biogenic nanoparticles into cells endow magnetic activity and (ii) low numbers of MNP-loaded cells are readily detected by MRI.

  15. Direct ex vivo analysis of dendritic cells in patients with hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Lars A Ormandy; Tim F Greten; Anatol F(a)rber; Tobias Cantz; Susanne Petrykowska; Heiner Wedemeyer; Monique H(o)rning; Frank Lehner; Michael P Manns; Firouzeh Korangy

    2006-01-01

    AIM: To analyze the phenotype and function of dendritic cells (DC) from patients with hepatocellular carcinoma (HCC) in order to understand their role in this disease.METHODS: Myeloid dendritic cells were enumerated in peripheral blood of HCC patients. CD80, CD83, CD86 and HLA-DR expression on naive and stimulated myeloid dendritic cells from peripheral blood were analyzed. Myeloid dendritic cells were isolated from peripheral blood and their function was tested. Phagocytosis was analyzed using FITC-dextran beads, peptide specific stimulation, the capacity to stimulate allogeneic T cells and secretion of cytokines upon poly dI:dC was tested.RESULTS: Myeloid dendritic cells were reduced in patients with HCC. No differences in CD80, CD83, CD86 and HLA-DR expression were found on naive and stimulated myeloid dendritic cells from HCC patients and healthy controls. Normal phagocytosis or stimulation of peptide specific T cells was observed in contrast to an impaired allo-stimulatory capacity and a reduced IL-12 secretion.CONCLUSION: Impaired IL-12 production of mDCs in patients could lead to an impaired stimulatory capacity of naive T cells suggesting that IL-12 directed therapies may enhance tumor specific immune responses in HCC patients.

  16. Monocyte cell surface glycosaminoglycans positively modulate IL-4-induced differentiation toward dendritic cells.

    NARCIS (Netherlands)

    Dekker, E. den; Grefte, S.; Huijs, T.; Dam, G.B. ten; Versteeg, E.M.M.; Berk, L.C.J. van den; Bladergroen, B.A.; Kuppevelt, A.H.M.S.M. van; Figdor, C.G.; Torensma, R.

    2008-01-01

    IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expr

  17. Glycyrrhiza uralensis water extract enhances dendritic cell maturation and antitumor efficacy of HPV dendritic cell-based vaccine

    Science.gov (United States)

    Aipire, Adila; Li, Jinyu; Yuan, Pengfei; He, Jiang; Hu, Yelang; Liu, Lu; Feng, Xiaoli; Li, Yijie; Zhang, Fuchun; Yang, Jianhua; Li, Jinyao

    2017-01-01

    Licorice has been used as herbal medicine and natural sweetener. Here, we prepared Glycyrrhiza uralensis water extract (GUWE) and investigated the effect of GUWE on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We observed that GUWE dose-dependently promoted DC maturation and cytokine secretion through TLR4 signaling pathway. The capacity of DC to stimulate allogenic splenocyte proliferation was also enhanced by GUWE treatment. Compared with control group, GUWE treated DCs pulsed with human papillomavirus (HPV)-16 E6/E7 peptides significantly inhibited the tumor growth in both early and late therapeutic groups. In early therapeutic group, the frequencies of induced regulatory T cells (iTregs: CD4+CD25−Fopx3+) and CD4+ and CD8+ T cells were significantly decreased and increased, respectively. HPV-16-specific CD8+ T cell responses were significantly induced and negatively correlated with iTreg frequencies and tumor weight. These results indicated the immunoregulatory activities of licorice. PMID:28272545

  18. Glycyrrhiza uralensis water extract enhances dendritic cell maturation and antitumor efficacy of HPV dendritic cell-based vaccine.

    Science.gov (United States)

    Aipire, Adila; Li, Jinyu; Yuan, Pengfei; He, Jiang; Hu, Yelang; Liu, Lu; Feng, Xiaoli; Li, Yijie; Zhang, Fuchun; Yang, Jianhua; Li, Jinyao

    2017-03-08

    Licorice has been used as herbal medicine and natural sweetener. Here, we prepared Glycyrrhiza uralensis water extract (GUWE) and investigated the effect of GUWE on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We observed that GUWE dose-dependently promoted DC maturation and cytokine secretion through TLR4 signaling pathway. The capacity of DC to stimulate allogenic splenocyte proliferation was also enhanced by GUWE treatment. Compared with control group, GUWE treated DCs pulsed with human papillomavirus (HPV)-16 E6/E7 peptides significantly inhibited the tumor growth in both early and late therapeutic groups. In early therapeutic group, the frequencies of induced regulatory T cells (iTregs: CD4(+)CD25(-)Fopx3(+)) and CD4(+) and CD8(+) T cells were significantly decreased and increased, respectively. HPV-16-specific CD8(+) T cell responses were significantly induced and negatively correlated with iTreg frequencies and tumor weight. These results indicated the immunoregulatory activities of licorice.

  19. Neuromelanin is an immune stimulator for dendritic cells in vitro

    Directory of Open Access Journals (Sweden)

    Oberländer Uwe

    2011-11-01

    Full Text Available Abstract Background Parkinson's disease (PD is characterized at the cellular level by a destruction of neuromelanin (NM-containing dopaminergic cells and a profound reduction in striatal dopamine. It has been shown recently that anti-melanin antibodies are increased in sera of Parkinson patients, suggesting that NM may act as an autoantigen. In this study we tested whether NM is being recognized by dendritic cells (DCs, the major cell type for inducing T- and B-cell responses in vivo. This recognition of NM by DCs is a prerequisite to trigger an adaptive autoimmune response directed against NM-associated structures. Results Murine DCs were treated with NM of substantia nigra (SN from human subjects or with synthetic dopamine melanin (DAM. DCs effectively phagocytized NM and subsequently developed a mature phenotype (CD86high/MHCIIhigh. NM-activated DCs secreted the proinflammatory cytokines IL-6 and TNF-α. In addition, they potently triggered T cell proliferation in a mixed lymphocyte reaction, showing that DC activation was functional to induce a primary T cell response. In contrast, DAM, which lacks the protein and lipid components of NM but mimics the dopamine-melanin backbone of NM, had only very little effect on DC phenotype and function. Conclusions NM is recognized by DCs in vitro and triggers their maturation. If operative in vivo, this would allow the DC-mediated transport and presentation of SN antigens to the adaptive immune system, leading to autoimmmunity in susceptible individuals. Our data provide a rationale for an autoimmune-based pathomechanism of PD with NM as the initial trigger.

  20. Antitumour activities of cytokine-induced killer cells and dendritic cells in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    ZHANG Song; JIANG Shu-juan; ZHANG Cai-qing; WANG Hong-mei; BAI Chun-xue

    2005-01-01

    @@ Solid tumour cells show a resistance to immunological effector cells in vitro.1 The resistance may be one reason why these tumours withstand immunotherapeutic approaches in humans.Dendritic cells (DC) play an important role in the immune response to tumour associated antigens in humans.DC in the periphery capture and process antigens,express lymphocyte costimulatory molecules,migrate to lymphoid organs and secrete cytokines to initiate immune response.

  1. Mesenchymal Stem Cells Inhibit Dendritic Cell Maturation and Their Allosti mulatory Capacity

    Institute of Scientific and Technical Information of China (English)

    Sophie; PACZESNY; Veronique; LATGER; CANNARD; Luc; MARCHAL; Bernard; FOLLIGUET; Jean-Franéois; STOLTZ; Assia; ELJAAFARI

    2005-01-01

    1 IntroductionDendritic cells (DC) are the most potent antigen-presenting cells. They play an important role in both initiation of immunity and maintenance of immune tolerance. In the recent years, they have been used in humans for the treatment of tumors. DCs are very poor in blood; however, they can be generated in vitro from either CD34~+ hematopoietic stem cell precursors or peripheral blood monocytes, by using appropriate cytokines~([1]). However, the microenvironment can influence their differentiatio...

  2. Type I TARPs promote dendritic growth of early postnatal neocortical pyramidal cells in organotypic cultures.

    Science.gov (United States)

    Hamad, Mohammad I K; Jack, Alexander; Klatt, Oliver; Lorkowski, Markus; Strasdeit, Tobias; Kott, Sabine; Sager, Charlotte; Hollmann, Michael; Wahle, Petra

    2014-04-01

    The ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazole propionate glutamate receptors (AMPARs) have been implicated in the establishment of dendritic architecture. The transmembrane AMPA receptor regulatory proteins (TARPs) regulate AMPAR function and trafficking into synaptic membranes. In the current study, we employ type I and type II TARPs to modulate expression levels and function of endogenous AMPARs and investigate in organotypic cultures (OTCs) of rat occipital cortex whether this influences neuronal differentiation. Our results show that in early development [5-10 days in vitro (DIV)] only the type I TARP γ-8 promotes pyramidal cell dendritic growth by increasing spontaneous calcium amplitude and GluA2/3 expression in soma and dendrites. Later in development (10-15 DIV), the type I TARPs γ-2, γ-3 and γ-8 promote dendritic growth, whereas γ-4 reduced dendritic growth. The type II TARPs failed to alter dendritic morphology. The TARP-induced dendritic growth was restricted to the apical dendrites of pyramidal cells and it did not affect interneurons. Moreover, we studied the effects of short hairpin RNA-induced knockdown of endogenous γ-8 and showed a reduction of dendritic complexity and amplitudes of spontaneous calcium transients. In addition, the cytoplasmic tail (CT) of γ-8 was required for dendritic growth. Single-cell calcium imaging showed that the γ-8 CT domain increases amplitude but not frequency of calcium transients, suggesting a regulatory mechanism involving the γ-8 CT domain in the postsynaptic compartment. Indeed, the effect of γ-8 overexpression was reversed by APV, indicating a contribution of NMDA receptors. Our results suggest that selected type I TARPs influence activity-dependent dendritogenesis of immature pyramidal neurons.

  3. Mitochondrial fission protein Drp1 regulates mitochondrial transport and dendritic arborization in cerebellar Purkinje cells.

    Science.gov (United States)

    Fukumitsu, Kansai; Hatsukano, Tetsu; Yoshimura, Azumi; Heuser, John; Fujishima, Kazuto; Kengaku, Mineko

    2016-03-01

    Mitochondria dynamically change their shape by repeated fission and fusion in response to physiological and pathological conditions. Recent studies have uncovered significant roles of mitochondrial fission and fusion in neuronal functions, such as neurotransmission and spine formation. However, the contribution of mitochondrial fission to the development of dendrites remains controversial. We analyzed the function of the mitochondrial fission GTPase Drp1 in dendritic arborization in cerebellar Purkinje cells. Overexpression of a dominant-negative mutant of Drp1 in postmitotic Purkinje cells enlarged and clustered mitochondria, which failed to exit from the soma into the dendrites. The emerging dendrites lacking mitochondrial transport remained short and unstable in culture and in vivo. The dominant-negative Drp1 affected neither the basal respiratory function of mitochondria nor the survival of Purkinje cells. Enhanced ATP supply by creatine treatment, but not reduced ROS production by antioxidant treatment, restored the hypomorphic dendrites caused by inhibition of Drp1 function. Collectively, our results suggest that Drp1 is required for dendritic distribution of mitochondria and thereby regulates energy supply in growing dendritic branches in developing Purkinje cells.

  4. Dendritic Cells and Multiple Sclerosis: Disease, Tolerance and Therapy

    Directory of Open Access Journals (Sweden)

    Mohammad G. Mohammad

    2012-12-01

    Full Text Available Multiple sclerosis (MS is a devastating neurological disease that predominantly affects young adults resulting in severe personal and economic impact. The majority of therapies for this disease were developed in, or are beneficial in experimental autoimmune encephalomyelitis (EAE, the animal model of MS. While known to target adaptive anti-CNS immune responses, they also target, the innate immune arm. This mini-review focuses on the role of dendritic cells (DCs, the professional antigen presenting cells of the innate immune system. The evidence for a role for DCs in the appropriate regulation of anti-CNS autoimmune responses and their role in MS disease susceptibility and possible therapeutic utility are discussed. Additionally, the current controversy regarding the evidence for the presence of functional DCs in the normal CNS is reviewed. Furthermore, the role of CNS DCs and potential routes of their intercourse between the CNS and cervical lymph nodes are considered. Finally, the future role that this nexus between the CNS and the cervical lymph nodes might play in site directed molecular and cellular therapy for MS is outlined.

  5. Dendritic Cells as a Pharmacological Target of Traditional Chinese Medicine

    Institute of Scientific and Technical Information of China (English)

    Xin Chen; Lu Yang; O. M. Zack Howard; Joost J. Oppenheim

    2006-01-01

    Dendritic cells (DCs) represent a heterogeneous population of professional antigen-presenting cells (APCs) that play a central role in the initiation and regulation of immune responses. There is considerable evidence that DCs can be used as therapeutic targets for pharmacological modulation of immune responses. Traditional Chines emedicine (TCM) has a long-standing history of using herbal medicine in the treatment of variety of human diseases.Many of the clinical effects of TCM have reportedly been attributed to the up- or down-regulation of immune responses. Accumulating evidence indicates that TCM and its components can interfere with immune responses at the earliest stage by targeting key functions of DCs. Here, we review those published studies of TCM with respect to their effects on immunobiological functions of DCs. Investigations based on both chemical entities derived from TCM as well as TCM herbal mixtures are presented. These studies suggest that various TCM herbal medicines have the capacity to inhibit or promote major functions of DCs, such as differentiation, maturation, cytokine production, survival, antigen uptake and presentation as well as trafficking. These studies have revealed novel biological effects of TCM and documented the utility of this approach to discover novel biological modifier of DC functions derived from natural sources.

  6. On dendritic cell-based therapy for cancers

    Institute of Scientific and Technical Information of China (English)

    Morikazu Onji; Sk. Md. Fazle Akbar

    2005-01-01

    Dendritic cells (DCs), the most prevalent antigen-presenting cell in vivo, had been widely characterized in the last three decades. DCs are present in almost all tissues of the body and play cardinal roles in recognition of microbial agents,autoantigens, allergens and alloantigen. DCs process the microbial agents or their antigens and migrate to lymphoid tissues to present the antigenic peptide to lymphocytes. This leads to activation of antigen-specific lymphocytes. Initially, it was assumed that DCs are principally involved in the induction and maintenance of adaptive immune responses, but now it is evident that DCs also have important roles in innate immunity. These features make DCs very good candidates for therapy against various pathological conditions including malignancies. Initially, DC-based therapy was used in animal models of cancers. Data from these studies inspired considerable optimism and DC-based therapies was started in human cancers 8 years ago. In general,DC-based therapy has been found to be safe in patients with cancers, although few controlled trials have been conducted in this regard. Because the fundamentals principles of human cancers and animal models of cancers are different, the therapeutic efficacy of the ongoing regime of DC-based therapy in cancer patients is not satisfactory. In this review, we covered the various aspects that should be considered for developing better regime of DC-based therapy for human cancers.

  7. Mannoproteins from Cryptococcus neoformans promote dendritic cell maturation and activation.

    Science.gov (United States)

    Pietrella, Donatella; Corbucci, Cristina; Perito, Stefano; Bistoni, Giovanni; Vecchiarelli, Anna

    2005-02-01

    Our previous data show that mannoproteins (MPs) from Cryptococcus neoformans are able to induce protective responses against both C. neoformans and Candida albicans. Here we provide evidence that MPs foster maturation and activation of human dendritic cells (DCs). Maturation was evaluated by the ability of MPs to facilitate expression of costimulatory molecules such as CD40, CD86, CD83, and major histocompatibility complex classes I and II and to inhibit receptors such as CD14, CD16, and CD32. Activation of DCs was measured by the capacity of MPs to promote interleukin-12 and tumor necrosis factor alpha secretion. DC-induced maturation and interleukin-12 induction are largely mediated by engagement of mannose receptors and presume MP internalization and degradation. DC activation leads to IkappaBalpha phosphorylation, which is necessary for nuclear factor kappaB transmigration into the nucleus. MP-loaded DCs are efficient stimulators of T cells and show a remarkable capacity to promote CD4 and CD8 proliferation. In conclusion, we have evidenced a novel regulatory role of MPs that promotes their candidacy as a vaccine against fungi.

  8. Echinacea pupurea extracts modulate murine dendritic cell fate and function

    Science.gov (United States)

    Benson, Jenna M.; Pokorny, Amanda J.; Rhule, Ava; Wenner, Cynthia A.; Kandhi, Vamsikrishna; Cech, Nadja B.; Shepherd, David M.

    2010-01-01

    Echinacea is a top-selling herbal remedy that purportedly acts as an immunostimulant. However, the specific immunomodulatory effects of Echinacea remain to be elucidated. We focused on defining the effects of Echinacea purpurea extracts in dendritic cells (DCs), which generate innate and adaptive immune responses. We hypothesized that E. purpurea extracts would enhance murine bone marrow-derived DC (BMDC) activation leading to increased immune responses. The fate and function of DCs from C57Bl/6 mice was evaluated following 48 h exposure to E. purpurea root and leaf extracts. Flow cytometry revealed that the polysaccharide-rich root extract increased the expression of MHC class II, CD86, and CD54 surface biomarkers whereas the alkylamide-rich leaf extract inhibited expression of these molecules. Production of IL-6 and TNF-α increased in a concentration-dependent manner with exposure to the root, but not leaf, extract. In contrast, the leaf but not root extract inhibited the enzymatic activity of cyclooxygenase-2. While both extracts decreased the uptake of ovalbumin by BMDCs, the leaf but not root extract inhibited the antigen-specific activation of naïve CD4+ T cells from OT II/Thy1.1 mice. Collectively, these results suggest that E. purpurea can be immunostimulatory, immunosuppressive, and/or anti-inflammatory depending on the portion of the plant and extraction method. PMID:20149833

  9. Echinacea purpurea extracts modulate murine dendritic cell fate and function.

    Science.gov (United States)

    Benson, Jenna M; Pokorny, Amanda J; Rhule, Ava; Wenner, Cynthia A; Kandhi, Vamsikrishna; Cech, Nadja B; Shepherd, David M

    2010-05-01

    Echinacea is a top-selling herbal remedy that purportedly acts as an immunostimulant. However, the specific immunomodulatory effects of Echinacea remain to be elucidated. We focused on defining the effects of Echinacea purpurea extracts in dendritic cells (DCs), which generate innate and adaptive immune responses. We hypothesized that E. purpurea extracts would enhance murine bone marrow-derived DC (BMDC) activation leading to increased immune responses. The fate and function of DCs from C57Bl/6 mice was evaluated following 48h exposure to E. purpurea root and leaf extracts. Flow cytometry revealed that the polysaccharide-rich root extract increased the expression of MHC class II, CD86, and CD54 surface biomarkers whereas the alkylamide-rich leaf extract inhibited expression of these molecules. Production of IL-6 and TNF-alpha increased in a concentration-dependent manner with exposure to the root, but not leaf, extract. In contrast, the leaf but not root extract inhibited the enzymatic activity of cyclooxygenase-2. While both extracts decreased the uptake of ovalbumin by BMDCs, the leaf but not root extract inhibited the antigen-specific activation of naïve CD4(+) T cells from OT II/Thy1.1 mice. Collectively, these results suggest that E. purpurea can be immunostimulatory, immunosuppressive, and/or anti-inflammatory depending on the portion of the plant and extraction method. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  10. Dendritic Cell-Based Vaccine Against Fungal Infection.

    Science.gov (United States)

    Ueno, Keigo; Urai, Makoto; Ohkouchi, Kayo; Miyazaki, Yoshitsugu; Kinjo, Yuki

    2016-01-01

    Several pathogenic fungi, including Cryptococcus gattii, Histoplasma capsulatum, Coccidioides immitis, and Penicillium marneffei, cause serious infectious diseases in immunocompetent humans. However, currently, prophylactic and therapeutic vaccines are not clinically used. In particular, C. gattii is an emerging pathogen and thus far protective immunity against this pathogen has not been well characterized. Experimental vaccines such as component and attenuated live vaccines have been used as tools to study protective immunity against fungal infection. Recently, we developed a dendritic cell (DC)-based vaccine to study protective immunity against pulmonary infection by highly virulent C. gattii strain R265 that was clinically isolated from bronchial washings of infected patients during the Vancouver Island outbreak. In this approach, bone marrow-derived DCs (BMDCs) are pulsed with heat-killed C. gattii and then transferred into mice prior to intratracheal infection. This DC vaccine significantly increases interleukin 17A (IL-17A)-, interferon gamma (IFN-γ)-, and tumor necrosis factor alpha (TNF-α)-producing T cells in the lungs and spleen and ameliorates the pathology, fungal burden, and mortality following C. gattii infection. This approach may result in the development of a new means of controlling lethal fungal infections. In this chapter, we describe the procedures of DC vaccine preparation and murine pulmonary infection model for analysis of immune response against C. gattii.

  11. Glycan Sulfation Modulates Dendritic Cell Biology and Tumor Growth

    Directory of Open Access Journals (Sweden)

    Roland El Ghazal

    2016-05-01

    Full Text Available In cancer, proteoglycans have been found to play roles in facilitating the actions of growth factors, and effecting matrix invasion and remodeling. However, little is known regarding the genetic and functional importance of glycan chains displayed by proteoglycans on dendritic cells (DCs in cancer immunity. In lung carcinoma, among other solid tumors, tumor-associated DCs play largely subversive/suppressive roles, promoting tumor growth and progression. Herein, we show that targeting of DC glycan sulfation through mutation in the heparan sulfate biosynthetic enzyme N-deacetylase/N-sulfotransferase-1 (Ndst1 in mice increased DC maturation and inhibited trafficking of DCs to draining lymph nodes. Lymphatic-driven DC migration and chemokine (CCL21-dependent activation of a major signaling pathway required for DC migration (as measured by phospho-Akt were sensitive to Ndst1 mutation in DCs. Lewis lung carcinoma tumors in mice deficient in Ndst1 were reduced in size. Purified CD11c+ cells from the tumors, which contain the tumor-infiltrating DC population, showed a similar phenotype in mutant cells. These features were replicated in mice deficient in syndecan-4, the major heparan sulfate proteoglycan expressed on the DC surface: Tumors were growth-impaired in syndecan-4–deficient mice and were characterized by increased infiltration by mature DCs. Tumors on the mutant background also showed greater infiltration by NK cells and NKT cells. These findings indicate the genetic importance of DC heparan sulfate proteoglycans in tumor growth and may guide therapeutic development of novel strategies to target syndecan-4 and heparan sulfate in cancer.

  12. Neuropeptides control the dynamic behavior of airway mucosal dendritic cells.

    Science.gov (United States)

    Voedisch, Sabrina; Rochlitzer, Sabine; Veres, Tibor Z; Spies, Emma; Braun, Armin

    2012-01-01

    The airway mucosal epithelium is permanently exposed to airborne particles. A network of immune cells patrols at this interface to the environment. The interplay of immune cells is orchestrated by different mediators. In the current study we investigated the impact of neuronal signals on key functions of dendritic cells (DC). Using two-photon microscopic time-lapse analysis of living lung sections from CD11c-EYFP transgenic mice we studied the influence of neuropeptides on airway DC motility. Additionally, using a confocal microscopic approach, the phagocytotic capacity of CD11c(+) cells after neuropeptide stimulation was determined. Electrical field stimulation (EFS) leads to an unspecific release of neuropeptides from nerves. After EFS and treatment with the neuropeptides vasoactive intestinal peptide (VIP) or calcitonin gene-related peptide (CGRP), airway DC in living lung slices showed an altered motility. Furthermore, the EFS-mediated effect could partially be blocked by pre-treatment with the receptor antagonist CGRP(8-37). Additionally, the phagocytotic capacity of bone marrow-derived and whole lung CD11c(+) cells could be inhibited by neuropeptides CGRP, VIP, and Substance P. We then cross-linked these data with the in vivo situation by analyzing DC motility in two different OVA asthma models. Both in the acute and prolonged OVA asthma model altered neuropeptide amounts and DC motility in the airways could be measured. In summary, our data suggest that neuropeptides modulate key features motility and phagocytosis of mouse airway DC. Therefore altered neuropeptide levels in airways during allergic inflammation have impact on regulation of airway immune mechanisms and therefore might contribute to the pathophysiology of asthma.

  13. Quantitative Determination of Ceramide Molecular Species in Dendritic Cells

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    Samar Al Makdessi

    2016-09-01

    Full Text Available Background/Aims: The activation of acid sphingomyelinase by cellular stress or receptors or the de novo synthesis lead to the formation of ceramide (N-acylsphingosine, which in turn modifies the biophysical properties of cellular membrane and greatly amplifies the intensity of the initial signal. Ceramide, which acts by re-organizing a given signalosome rather than being a second messenger, has many functions in infection biology, cancer, cardiovascular syndromes, and immune regulation. Experimental studies on the infection of human cells with different bacterial agents demonstrated the activation of the acid sphingomyelinase/ceramide system. Moreover, the release of ceramide was found to be a requisite for the uptake of the pathogen. Considering the particular importance of the cellular role of ceramide, it was necessary to develop sensitive and accurate methods for its quantification. Methods: Here, we describe a method quantifying ceramide in dendritic cells and defining the different fatty acids (FA bound to sphingosine. The main steps of the method include extraction of total lipids, separation of the ceramide by thin-layer chromatography, derivatization of ceramide-fatty acids (Cer-FA, and quantitation of these acids in their methyl form by gas chromatography on polar capillary columns. The identification of FA was achieved by means of known standards and confirmed by mass spectrometry. Results: FA ranging between C10 and C24 could be detected and quantified. The concentration of the sum of Cer-FA amounted to 14.88 ± 8.98 nmol/106 cells (n=10. Oleic acid, which accounted for approximately half of Cer-FA (7.73 ± 6.52 nmol/106 cells was the predominant fatty acid followed by palmitic acid (3.47 ± 1.54 nmol/106 cells. Conclusion: This highly sensitive method allows the quantification of different molecular species of ceramides.

  14. Glycan Sulfation Modulates Dendritic Cell Biology and Tumor Growth.

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    El Ghazal, Roland; Yin, Xin; Johns, Scott C; Swanson, Lee; Macal, Monica; Ghosh, Pradipta; Zuniga, Elina I; Fuster, Mark M

    2016-05-01

    In cancer, proteoglycans have been found to play roles in facilitating the actions of growth factors, and effecting matrix invasion and remodeling. However, little is known regarding the genetic and functional importance of glycan chains displayed by proteoglycans on dendritic cells (DCs) in cancer immunity. In lung carcinoma, among other solid tumors, tumor-associated DCs play largely subversive/suppressive roles, promoting tumor growth and progression. Herein, we show that targeting of DC glycan sulfation through mutation in the heparan sulfate biosynthetic enzyme N-deacetylase/N-sulfotransferase-1 (Ndst1) in mice increased DC maturation and inhibited trafficking of DCs to draining lymph nodes. Lymphatic-driven DC migration and chemokine (CCL21)-dependent activation of a major signaling pathway required for DC migration (as measured by phospho-Akt) were sensitive to Ndst1 mutation in DCs. Lewis lung carcinoma tumors in mice deficient in Ndst1 were reduced in size. Purified CD11c+ cells from the tumors, which contain the tumor-infiltrating DC population, showed a similar phenotype in mutant cells. These features were replicated in mice deficient in syndecan-4, the major heparan sulfate proteoglycan expressed on the DC surface: Tumors were growth-impaired in syndecan-4-deficient mice and were characterized by increased infiltration by mature DCs. Tumors on the mutant background also showed greater infiltration by NK cells and NKT cells. These findings indicate the genetic importance of DC heparan sulfate proteoglycans in tumor growth and may guide therapeutic development of novel strategies to target syndecan-4 and heparan sulfate in cancer.

  15. Dendritic cell-based immunotherapy for myeloid leukemias.

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    Schürch, Christian M; Riether, Carsten; Ochsenbein, Adrian F

    2013-12-31

    Acute and chronic myeloid leukemia (AML, CML) are hematologic malignancies arising from oncogene-transformed hematopoietic stem/progenitor cells known as leukemia stem cells (LSCs). LSCs are selectively resistant to various forms of therapy including irradiation or cytotoxic drugs. The introduction of tyrosine kinase inhibitors has dramatically improved disease outcome in patients with CML. For AML, however, prognosis is still quite dismal. Standard treatments have been established more than 20 years ago with only limited advances ever since. Durable remission is achieved in less than 30% of patients. Minimal residual disease (MRD), reflected by the persistence of LSCs below the detection limit by conventional methods, causes a high rate of disease relapses. Therefore, the ultimate goal in the treatment of myeloid leukemia must be the eradication of LSCs. Active immunotherapy, aiming at the generation of leukemia-specific cytotoxic T cells (CTLs), may represent a powerful approach to target LSCs in the MRD situation. To fully activate CTLs, leukemia antigens have to be successfully captured, processed, and presented by mature dendritic cells (DCs). Myeloid progenitors are a prominent source of DCs under homeostatic conditions, and it is now well established that LSCs and leukemic blasts can give rise to "malignant" DCs. These leukemia-derived DCs can express leukemia antigens and may either induce anti-leukemic T cell responses or favor tolerance to the leukemia, depending on co-stimulatory or -inhibitory molecules and cytokines. This review will concentrate on the role of DCs in myeloid leukemia immunotherapy with a special focus on their generation, application, and function and how they could be improved in order to generate highly effective and specific anti-leukemic CTL responses. In addition, we discuss how DC-based immunotherapy may be successfully integrated into current treatment strategies to promote remission and potentially cure myeloid leukemias.

  16. Dendritic cell-based immunotherapy for myeloid leukemias

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    Christian Martijn Schürch

    2013-12-01

    Full Text Available Acute and chronic myeloid leukemia (AML, CML are hematologic malignancies arising from oncogene-transformed hematopoietic stem/progenitor cells known as leukemia stem cells (LSCs. LSCs are selectively resistant to various forms of therapy including irradiation or cytotoxic drugs. The introduction of tyrosine kinase inhibitors has dramatically improved disease outcome in patients with CML. For AML, however, prognosis is still quite dismal. Standard treatments have been established more than 20 years ago with only limited advances ever since. Durable remission is achieved in less than 30% of patients. Minimal residual disease (MRD, reflected by the persistence of LSCs below the detection limit by conventional methods, causes a high rate of disease relapses. Therefore, the ultimate goal in the treatment of myeloid leukemia must be the eradication of LSCs. Active immunotherapy, aiming at the generation of leukemia-specific cytotoxic T cells (CTLs, may represent a powerful approach to target LSCs in the MRD situation. To fully activate CTLs, leukemia antigens have to be successfully captured, processed and presented by mature dendritic cells (DCs. Myeloid progenitors are a prominent source of DCs under homeostatic conditions, and it is now well established that LSCs and leukemic blasts can give rise to malignant DCs. These leukemia-derived DCs can express leukemia antigens and may either induce anti-leukemic T cell responses or favor tolerance to the leukemia, depending on co-stimulatory or -inhibitory molecules and cytokines. This review will concentrate on the role of DCs in myeloid leukemia immunotherapy with a special focus on their generation, application and function and how they could be improved in order to generate highly effective and specific anti-leukemic CTL responses. In addition, we discuss how DC-based immunotherapy may be successfully integrated into current treatment strategies to promote remission and potentially cure myeloid

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

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    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

  18. Dendritic cells in hepatitis C virus infection: key players in the IFNL3-genotype response.

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    O'Connor, Kate S; George, Jacob; Booth, David; Ahlenstiel, Golo

    2014-12-21

    Recently, single nucleotide polymorphisms, in the vicinity of the interferon lambda 3 (IFNL3) gene have been identified as the strongest predictor of spontaneous and treatment induced clearance of hepatitis C virus (HCV) infection. Since then, increasing evidence has implicated the innate immune response in mediating the IFNL3 genotype effect. Dendritic cells (DCs) are key to the host immune response in HCV infection and their vital role in the IFNL3 genotype effect is emerging. Reports have identified subclasses of DCs, particularly myeloid DC2s and potentially plasmacytoid DCs as the major producers of IFNL3 in the setting of HCV infection. Given the complexities of dendritic cell biology and the conflicting current available data, this review aims to summarize what is currently known regarding the role of dendritic cells in HCV infection and to place it into context of what is know about lambda interferons and dendritic cells in general.

  19. Dendritic Properties Control Energy Efficiency of Action Potentials in Cortical Pyramidal Cells

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    Guosheng Yi

    2017-09-01

    Full Text Available Neural computation is performed by transforming input signals into sequences of action potentials (APs, which is metabolically expensive and limited by the energy available to the brain. The metabolic efficiency of single AP has important consequences for the computational power of the cell, which is determined by its biophysical properties and morphologies. Here we adopt biophysically-based two-compartment models to investigate how dendrites affect energy efficiency of APs in cortical pyramidal neurons. We measure the Na+ entry during the spike and examine how it is efficiently used for generating AP depolarization. We show that increasing the proportion of dendritic area or coupling conductance between two chambers decreases Na+ entry efficiency of somatic AP. Activating inward Ca2+ current in dendrites results in dendritic spike, which increases AP efficiency. Activating Ca2+-activated outward K+ current in dendrites, however, decreases Na+ entry efficiency. We demonstrate that the active and passive dendrites take effects by altering the overlap between Na+ influx and internal current flowing from soma to dendrite. We explain a fundamental link between dendritic properties and AP efficiency, which is essential to interpret how neural computation consumes metabolic energy and how biophysics and morphologies contribute to such consumption.

  20. The development of endometriosis in a murine model is dependent on the presence of dendritic cells.

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    Pencovich, Niv; Luk, Janelle; Hantisteanu, Shay; Hornstein, Mark D; Fainaru, Ofer

    2014-04-01

    Endometriosis is a common condition associated with pelvic pain and infertility. This study group has previously shown that supplementation of dendritic cells led to enhancement of endometriosis lesion growth and angiogenesis. This study determined whether endometriosis is dependent on the presence of endogenous dendritic cells. Surgical induction of endometriosis was performed in CD11c⁺ DTR/GFP transgenic (Tg) female mice in which dendritic cells were ablated upon injection of diphtheria toxin (DT). Mice were allocated into four groups (n=5 each): group I, wild-type mice treated with vehicle; group II, wild-type mice treated with DT; group III, Tg mice treated with DT; and group IV, Tg mice treated with vehicle. After 10 days, mice were killed and endometriosis lesions were analysed by flow cytometry. DT treatment led to ablation of dendritic cells in spleens and endometriosis lesions in Tg mice while no ablation was observed in controls. Corresponding to dendritic cell ablation, endometriosis lesions in group III were ∼5-fold smaller than in the control groups (ANOVA Pdendritic cells. Therapies designed to inhibit dendritic cell infiltration as possible treatments for endometriosis warrant further study.

  1. Study on immune function of dendritic cells in patients with esophageal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shen-Ren Chen; Yi-Ping Luo; Jin-Kun Zhang; Wei Yang; Zhi-Chao Zhen; Lin-Xin Chen; Wei Zhang

    2004-01-01

    AIM: To investigate the immune function of dendritic cells from both peripheral blood and operated tissues of esophageal carcinoma patients in order to find the relationship between the immune function of dendritic cells and the pathogenesis of esophageal carcinoma.METHODS: The expression of CD83, CD80, and CD86 on the surface of dendritic cells cultured from the peripheral blood of patients was detected compared with that from health donors using flow cytometry. The ability of dendritic cells to induce T lymphocyte proliferation was evaluated by a liquid scintillation counter. The expression of CD80, CD86,CD83, and S-100 proteins was assessed in esophageal carcinoma tissues using immunohistochemical method.RESULTS: Compared with those from healthy donors,dendirtic cells cultured from the peripheral blood of patients expressed lower CD80 and CD86. Furthermore, the ability of dendritic cells in patients to induce T lymphocyte proliferation was significantly lower than that of the control group. Compared with the control group, the positive expression ratio and frequencies of CDS0, CD86, and S100 in esophageal carcinoma tissues were significantly down regulated. The expression of CD83 was up-regulated in the pericancerous tissues, but no expression was found in the cancerous nodules,CONCLUSION: The impaired immune function and the decreased number of dendritic cells cause pathogenesis and progression of esophageal carcinoma.

  2. Dynamic imaging of cell-free and cell-associated viral capture in mature dendritic cells.

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    Izquierdo-Useros, Nuria; Esteban, Olga; Rodriguez-Plata, Maria T; Erkizia, Itziar; Prado, Julia G; Blanco, Julià; García-Parajo, Maria F; Martinez-Picado, Javier

    2011-12-01

    Dendritic cells (DCs) capture human immunodeficiency virus (HIV) through a non-fusogenic mechanism that enables viral transmission to CD4(+) T cells, contributing to in vivo viral dissemination. Although previous studies have provided important clues to cell-free viral capture by mature DCs (mDCs), dynamic and kinetic insight on this process is still missing. Here, we used three-dimensional video microscopy and single-particle tracking approaches to dynamically dissect both cell-free and cell-associated viral capture by living mDCs. We show that cell-free virus capture by mDCs operates through three sequential phases: virus binding through specific determinants expressed in the viral particle, polarized or directional movements toward concrete regions of the cell membrane and virus accumulation in a sac-like structure where trapped viral particles display a hindered diffusive behavior. Moreover, real-time imaging of cell-associated viral transfer to mDCs showed a similar dynamics to that exhibited by cell-free virus endocytosis leading to viral accumulation in compartments. However, cell-associated HIV type 1 transfer to mDCs was the most effective pathway, boosted throughout enhanced cellular contacts with infected CD4(+) T cells. Our results suggest that in lymphoid tissues, mDC viral uptake could occur either by encountering cell-free or cell-associated virus produced by infected cells generating the perfect scenario to promote HIV pathogenesis and impact disease progression.

  3. Characterization of colonic dendritic cells in normal and colitic mice

    Institute of Scientific and Technical Information of China (English)

    Sheena M Cruickshank; Nicholas R English; Peter J Felsburg; Simon R Carding

    2005-01-01

    AIM: Recent studies demonstrating the direct involvement of dendritic cells (DC) in the activation of pathogenic T cells in animal models of inflammatory bowel disease identify DC as important antigen presenting cells in the colon. However, very little is known about the properties of colonic DC.METHODS: Using immunohistochemistry, electron microscopy and flow cytometry we have characterized and compared colonic DC in the colon of healthy animals and interleukin-2-deficient (IL2-/-) mice that develop colitis.RESULTS: In the healthy colon, DC resided within the lamina propria and in close association with the basement membrane of colonic villi. Type 1 myeloid (CD11c+, CD11b+,B220-, CD8α-) DC made up the largest (40-45%) population and all DC expressed low levels of CD80, CD86, and CD40,and had high endocytic activity consistent with an immature phenotype. In colitic IL2-/- mice, colonic DC numbers increased four- to five-fold and were localized within the epithelial layer and within aggregates of T and B cells. They were also many more DC in mesenteric lymph nodes (MLN).The majority (>85%) of DC in the colon and MLN of IL2-/-mice were type 1 myeloid, and expressed high levels of MHC class Ⅱ, CD80, CD86, CD 40, DEC 205, and CCR5molecules and were of low endocytic activity consistent with mature DC.CONCLUSION: These findings demonstrate striking changes in the number, distribution and phenotype of DC in the inflamed colon. Their intimate association with lymphocytes in the colon and draining lymph nodes suggest that they may contribute directly to the ongoing inflammation in the colon.

  4. Expression and function of mixed lineage kinases in dendritic cells.

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    Handley, Matthew E; Rasaiyaah, Jane; Barnett, James; Thakker, Manish; Pollara, Gabriele; Katz, David R; Chain, Benjamin M

    2007-08-01

    Dendritic cells (DCs) sense the presence of conserved microbial structures in their local microenvironment via specific pattern recognition receptors (PRRs). This leads to a programme of changes, which include migration and activation, and enables them to induce adaptive T cell immunity. Mitogen-activated protein kinases (MAPKs) are implicated in this response, but the pathways leading from PRR ligation to MAPK activation, and hence DC activation, are not fully understood. Recent studies in the nervous system have suggested that the mixed lineage kinase (MLK) family of MAPK kinase kinase proteins may be involved as an intermediary step between PRRs and MAPKs. Therefore, in this study, we have used a well-established DC model to explore the role of MLKs in these cells. Messenger RNA for MLKs 2, 3, 4 and DLK and protein for MLKs 2, 3 and DLK are found in DC. DC activation in response to model PRR ligands, such as LPS or poly (I:C), is accompanied by phosphorylation of MLK3. In contrast, another known PRR ligand, zymosan, induces little MLK3 phosphorylation. Inhibition of MLK activity using a pharmacological inhibitor, CEP11004, blocks p38 and Jun N-terminal kinase (JNK) MAPK activation in response to LPS and poly (I:C), but not zymosan. The inhibition is associated with a block in DC activation as measured by cell-surface marker expression and cytokine secretion. Thus, MLKs are expressed in DC, and are implicated in DC activation, and the involvement of MLKs appears to be selective, depending on the nature of the DC stimulus.

  5. Interaction of tumor cells with the immune system: implications for dendritic cell therapy and cancer progression.

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    Imhof, Marianne; Karas, Irene; Gomez, Ivan; Eger, Andreas; Imhof, Martin

    2013-01-01

    There is a continuous demand for preclinical modeling of the interaction of dendritic cells with the immune system and cancer cells. Recent progress in gene expression profiling with nucleic acid microarrays, in silico modeling and in vivo cell and animal approaches for non-clinical proof of safety and efficacy of these immunotherapies is summarized. Immunoinformatic approaches look promising to unfold this potential, although still unstable and difficult to interpret. Animal models have progressed a great deal in recent years, finally narrowing the gap from bench to bedside. However, translation to the clinic should be done with precaution. The most significant results concerning clinical benefit might come from detailed immunologic investigations made during well designed clinical trials of dendritic-cell-based therapies, which in general prove safe.

  6. Melanoma cell-derived exosomes alter macrophage and dendritic cell functions in vitro.

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    Marton, Annamaria; Vizler, Csaba; Kusz, Erzsebet; Temesfoi, Viktoria; Szathmary, Zsuzsa; Nagy, Krisztina; Szegletes, Zsolt; Varo, Gyorgy; Siklos, Laszlo; Katona, Robert L; Tubak, Vilmos; Howard, O M Zack; Duda, Erno; Minarovits, Janos; Nagy, Katalin; Buzas, Krisztina

    2012-01-01

    To clarify controversies in the literature of the field, we have purified and characterized B16F1 melanoma cell derived exosomes (mcd-exosomes) then we attempted to dissect their immunological activities. We tested how mcd-exosomes influence CD4+ T cell proliferation induced by bone marrow derived dendritic cells; we quantified NF-κB activation in mature macrophages stimulated with mcd-exosomes, and we compared the cytokine profile of LPS-stimulated, IL-4 induced, and mcd-exosome treated macrophages. We observed that mcd-exosomes helped the maturation of dendritic cells, enhancing T cell proliferation induced by the treated dendritic cells. The exosomes also activated macrophages, as measured by NF-κB activation. The cytokine and chemokine profile of macrophages treated with tumor cell derived exosomes showed marked differences from those induced by either LPS or IL-4, and it suggested that exosomes may play a role in the tumor progression and metastasis formation through supporting tumor immune escape mechanisms.

  7. The microRNA bantam regulates a developmental transition in epithelial cells that restricts sensory dendrite growth.

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    Jiang, Nan; Soba, Peter; Parker, Edward; Kim, Charles C; Parrish, Jay Z

    2014-07-01

    As animals grow, many early born structures grow by cell expansion rather than cell addition; thus growth of distinct structures must be coordinated to maintain proportionality. This phenomenon is particularly widespread in the nervous system, with dendrite arbors of many neurons expanding in concert with their substrate to sustain connectivity and maintain receptive field coverage as animals grow. After rapidly growing to establish body wall coverage, dendrites of Drosophila class IV dendrite arborization (C4da) neurons grow synchronously with their substrate, the body wall epithelium, providing a system to study how proportionality is maintained during animal growth. Here, we show that the microRNA bantam (ban) ensures coordinated growth of C4da dendrites and the epithelium through regulation of epithelial endoreplication, a modified cell cycle that entails genome amplification without cell division. In Drosophila larvae, epithelial endoreplication leads to progressive changes in dendrite-extracellular matrix (ECM) and dendrite-epithelium contacts, coupling dendrite/substrate expansion and restricting dendrite growth beyond established boundaries. Moreover, changes in epithelial expression of cell adhesion molecules, including the beta-integrin myospheroid (mys), accompany this developmental transition. Finally, endoreplication and the accompanying changes in epithelial mys expression are required to constrain late-stage dendrite growth and structural plasticity. Hence, modulating epithelium-ECM attachment probably influences substrate permissivity for dendrite growth and contributes to the dendrite-substrate coupling that ensures proportional expansion of the two cell types.

  8. Tolerogenic dendritic cells show gene expression profiles that are different from those of immunogenic dendritic cells in DBA/1 mice.

    Science.gov (United States)

    Lee, Eun Gae; Jung, Nam-Chul; Lee, Jun-Ho; Song, Jie-Young; Ryu, Sang-Young; Seo, Han Geuk; Han, Sung Gu; Ahn, Keun Jae; Hong, Kwan Soo; Choi, Jinjung; Lim, Dae-Seog

    2016-01-01

    Tolerogenic dendritic cells (tDCs) play an important role in inducing peripheral tolerance; however, few tDC-specific markers have been identified. The aims of this study were to examine whether tDCs show a different gene expression profile from that of immunogenic DCs and identify specific gene markers of each cell type, in DBA/1 mice. tDCs were generated by treating immature DCs (imDCs) with TNF-α and type II collagen. The gene expression profiles of mature (m)DCs and tDCs were then investigated by microarray analysis and candidate markers were validated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Supervised selection identified 75 gene signatures, 63 of which were consistently upregulated in mDCs and 12 of which were upregulated only in tDCs. Additionally, 10 genes were overexpressed or equally expressed in both tDCs and mDCs. Scin (tDC-specific genes) and Orm1, Pdlim4 and Enpp2 (mDC-specific genes) were validated by real-time qRT-PCR. Taken together, these results clearly show that tDCs and mDCs can be identified according to their expression of specific gene markers.

  9. Cryptococcus gattii is killed by dendritic cells, but evades adaptive immunity by failing to induce dendritic cell maturation.

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    Huston, Shaunna M; Li, Shu Shun; Stack, Danuta; Timm-McCann, Martina; Jones, Gareth J; Islam, Anowara; Berenger, Byron M; Xiang, Richard F; Colarusso, Pina; Mody, Christopher H

    2013-07-01

    During adaptive immunity to pathogens, dendritic cells (DCs) capture, kill, process, and present microbial Ags to T cells. Ag presentation is accompanied by DC maturation driven by appropriate costimulatory signals. However, current understanding of the intricate regulation of these processes remains limited. Cryptococcus gattii, an emerging fungal pathogen in the Pacific Northwest of Canada and the United States, fails to stimulate an effective immune response in otherwise healthy hosts leading to morbidity or death. Because immunity to fungal pathogens requires intact cell-mediated immunity initiated by DCs, we asked whether C. gattii causes dysregulation of DC functions. C. gattii was efficiently bound and internalized by human monocyte-derived DCs, trafficked to late phagolysosomes, and killed. Yet, even with this degree of DC activation, the organism evaded pathways leading to DC maturation. Despite the ability to recognize and kill C. gattii, immature DCs failed to mature; there was no increased expression of MHC class II, CD86, CD83, CD80, and CCR7, or decrease of CD11c and CD32, which resulted in suboptimal T cell responses. Remarkably, no increase in TNF-α was observed in the presence of C. gattii. However, addition of recombinant TNF-α or stimulation that led to TNF-α production restored DC maturation and restored T cell responses. Thus, despite early killing, C. gattii evades DC maturation, providing a potential explanation for its ability to infect immunocompetent individuals. We have also established that DCs retain the ability to recognize and kill C. gattii without triggering TNF-α, suggesting independent or divergent activation pathways among essential DC functions.

  10. An Engineered Herpesvirus Activates Dendritic Cells and Induces Protective Immunity

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    Ma, Yijie; Chen, Min; Jin, Huali; Prabhakar, Bellur S.; Valyi-Nagy, Tibor; He, Bin

    2017-01-01

    Herpes simplex viruses (HSV) are human pathogens that switch between lytic and latent infection. While attenuated HSV is explored for vaccine, the underlying event remains poorly defined. Here we report that recombinant HSV-1 with a mutation in the γ134.5 protein, a virulence factor, stimulates dendritic cell (DC) maturation which is dependent on TANK-binding kinase 1 (TBK1). When exposed to CD11+ DCs, the mutant virus that lacks the amino terminus of γ134.5 undergoes temporal replication without production of infectious virus. Mechanistically, this leads to sequential phosphorylation of interferon regulatory factor 3 (IRF3) and p65/RelA. In correlation, DCs up-regulate the expression of co-stimulatory molecules and cytokines. However, selective inhibition of TBK1 precludes phosphorylation of IRF3 and subsequent DC activation by the γ134.5 mutant. Herein, the γ134.5 mutant is immune-stimulatory and non-destructive to DCs. Remarkably, upon immunization the γ134.5 mutant induces protection against lethal challenge by the wild type virus, indicative of its vaccine potential. Furthermore, CD11+ DCs primed by the γ134.5 mutant in vivo mediate protection upon adoptive transfer. These results suggest that activation of TBK1 by engineered HSV is crucial for DC maturation, which may contribute to protective immunity. PMID:28150813

  11. The Influence of Ouabain on Human Dendritic Cells Maturation

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    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.

  12. Immune receptors involved in Streptococcus suis recognition by dendritic cells.

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    Marie-Pier Lecours

    Full Text Available Streptococcus suis is an important swine pathogen and an emerging zoonotic agent of septicemia and meningitis. Knowledge on host immune responses towards S. suis, and strategies used by this pathogen for subversion of these responses is scarce. The objective of this study was to identify the immune receptors involved in S. suis recognition by dendritic cells (DCs. Production of cytokines and expression of co-stimulatory molecules by DCs were shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize S. suis and become activated mostly through Toll-like receptor (TLR signaling. Supporting this fact, TLR2(-/- DCs were severely impaired in the release of several cytokines and the surface expression of CD86 and MHC-II. The release of IL-12p70 and CXC10, and the expression of CD40 were found to depend on signaling by both TLR2 and TLR9. The release of IL-23 and CXCL1 were partially dependent on NOD2. Finally, despite the fact that MyD88 signaling was crucial for DC activation and maturation, MyD88-dependent pathways were not implicated in S. suis internalization by DCs. This first study on receptors involved in DC activation by S. suis suggests a major involvement of MyD88 signaling pathways, mainly (but not exclusively through TLR2. A multimodal recognition involving a combination of different receptors seems essential for DC effective response to S. suis.

  13. 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.

  14. Clinical grade of generation of dendritic cells for immunotherapy.

    Science.gov (United States)

    Tang, Duozhuang; Tao, Si; Cao, Yang; Zhou, Jianfeng; Ma, Ding; Huang, Wei

    2007-06-01

    In order to develop a protocol for clinical grade generation of dendritic cells (DCs) for cancer immunotherapy, aphereses were performed with the continuous flow cell separator and materials were derived from 10 leukemia patients that had achieved complete remission. Peripheral blood monocytes were cultured in vitro with GM-CSF, IL-4 for 6 days, then TNF-(the TNF-group) or TNF-, IL-1, IL-6, PGE2 (the cytokine mixture group) were added to promote maturation. Cell number was counted by hematology analyzer, and phenotype study (CD1a, CD14, CD83) was carried out by flow cytometry, and the function of DCs was examined by mixed lymphocyte reaction. The results showed that (0.70+/-0.13)x10(7)/mL (the TNF-alpha group) and (0.79+/-0.04)x10(7)/mL (the cytokine mixture group) DCs were generated respectively in peripheral blood obtained by leucapheresis. The phenotypes were as follows: CD1a+ (74.65+/-4.45)%, CD83+ (39.50+/-4.16)%, CD14+ (2.90+/-1.76)% in TNF-alpha group, and CD1a+ (81.86+/-5.87)%, CD83+ (81.65+/-6.36)%, CD14+ (2.46+/-1.68)% in the cytokine mixture group. It was concluded that leucapheresis may be a feasible way to provide large number of peripheral blood monocytes for DC generation, and combined administration of TNF-, IL-1, IL-6, and PGE2 may greatly promote maturity.

  15. Helicobacter pylori impairs murine dendritic cell responses to infection.

    Directory of Open Access Journals (Sweden)

    Ya-Hui Wang

    Full Text Available BACKGROUND: Helicobacter pylori, a human pathogen associated with chronic gastritis, peptic ulcer and gastric malignancies, is generally viewed as an extracellular microorganism. Here, we show that H. pylori replicates in murine bone marrow derived-dendritic cells (BMDCs within autophagosomes. METHODOLOGY/PRINCIPAL FINDINGS: A 10-fold increase of CFU is found between 2 h and 6 h p.i. in H. pylori-infected BMDCs. Autophagy is induced around the bacterium and participates at late time points of infection for the clearance of intracellular H. pylori. As a consequence of infection, LC3, LAMP1 and MHC class II molecules are retained within the H. pylori-containing vacuoles and export of MHC class II molecules to cell surface is blocked. However, formalin-fixed H. pylori still maintain this inhibitory activity in BMDC derived from wild type mice, but not in from either TLR4 or TLR2-deficient mice, suggesting the involvement of H. pylori-LPS in this process. TNF-alpha, IL-6 and IL-10 expression was also modulated upon infection showing a TLR2-specific dependent IL-10 secretion. No IL-12 was detected favoring the hypothesis of a down modulation of DC functions during H. pylori infection. Furthermore, antigen-specific T cells proliferation was also impaired upon infection. CONCLUSIONS/SIGNIFICANCE: H. pylori can infect and replicate in BMDCs and thereby affects DC-mediated immune responses. The implication of this new finding is discussed for the biological life cycle of H. pylori in the host.

  16. Intestinal dendritic cells in the pathogenesis of inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Sergio Rutella; Franco Locatelli

    2011-01-01

    The gastrointestinal tract harbors a large number and diverse array of commensal bacteria and is an important entry site for pathogens. For these reasons, the intestinal immune system is uniquely dedicated to protect against infections, while avoiding the development of destructive inflammatory responses to the microbiota. Several models have been proposed to explain how the immune system discriminates between, and appropriately responds to, commensal and pathogenic microorganisms. Dendritic cells (DCs) and regulatory T cells (Treg) are instrumental in maintaining immune homeostasis and tolerance in the gut. DCs are virtually omnipresent and are remarkably plastic, having the ability to adapt to the influences of the microenvironment. Different DC populations with partially overlapping phenotypic and functional properties have been described in different anatomical locations. DCs in the draining mesenteric lymph nodes, in the intestinal lamina propria and in Peyer's patches partake both in the control of intestinal inflammation and in the maintenance of gut tolerance. In this respect, gut-resident DCs and macrophages exert tolerogenic functions as they regularly encounter and sense commensal bacteria. In contrast, migrating DC subsets that are recruited to the gut as a result of pathogenic insults initiate immune responses. Importantly, tolerogenic DCs act by promoting the differentiation and expansion of Treg cells that efficiently modulate gut inflammation, as shown both in pre-clinical models of colitis and in patients with inflammatory bowel disease (IBD). This article reviews the phenotypic and functional features of gut DC subsets and discusses the current evidence underpinning the DC contribution to the pathogenesis of the major clinical subtypes of human IBD. It also addresses the potential clinical benefit derived from DC targeting either in vivo or in vitro.

  17. Clinical Grade of Gerneration of Dendritic Cells for Immunotherapy

    Institute of Scientific and Technical Information of China (English)

    TANG Duozhuang; TAO Si; CAO Yang; ZHOU Jianfeng; MA Ding; HUANG Wei

    2007-01-01

    In order to develop a protocol for clinical grade generation of dendritic cells (DCs) for cancer immumotherapy, aphereses were performed with the continuous flow cell separator and materials were derived from 10 leukemia patients that had achieved complete remission. Peripheral blood monocytes were cultured in vitro with GM-CSF, IL-4 for 6 days, then TNF-α (the TNF-α group) or TNF-α, IL-1β, IL-6, PGE2 (the cytokine mixture group) were added to promote maturation. Cell number was counted by hematology analyzer, and phenotype study (CD1a, CD14, CD83) was carried out by flow cytometry, and the function of DCs was examined by mixed lymphocyte reaction. The results showed that (0.70±0.13)×107/mL (the TNF-α group) and (0.79±0.04)×107/mL (the cytokine mixture group) DCs were generated respectively in peripheral blood obtained by leucapheresis. The phenotypes were as follows: CD1a+ (74.65±4.45)%, CD83+(39.50±4.16)%, CD14+(2.90±1.76)% in TNF-α group, and CD1a+ (81.86±5.87)%, CD83+ (81.65±6.36)%, CD14+ (2.46±1.68)% in the cytokine mixture group. It was concluded that leucapheresis may be a feasible way to provide large number of peripheral blood monocytes for DC generation, and combined administration of TNF-α, IL-1β,IL-6, and PGE2 may greatly promote maturity.

  18. [Experimental study on activating antileukemic T cells by vaccination with dendritic cells pulsed with survivin].

    Science.gov (United States)

    Zhang, Xiao-Hui; Xia, Ling-Hui; Liu, Zhong-Ping; Wei, Wen-Ning; Hu, Yu; Song, Shan-Jun

    2003-02-01

    The objective of this study is to investigate the effect of vaccination with dendritic cells pulsed with survivin antigen on activation of antileukemic T cells, and inhibiting proliferation of leukemic cells. The expression of survivin on acute leukemic cells were detected by cofocal microscopy and immunoprecipitation-Western blot. DCs collected from peripheral blood mononuclear cells were pulsed with survivin purified proteins. Stimulation index (SI) and antileukemia CTL induction were analyzed with (3)H-TdR incorporation and (51)Cr releasing assay, respectively. The phenotype of T cells and DCs were identified by flow cytometry. By immunofluorescence of bone marrow and peripheral blood mononuclear cells, survivin expression was detected in 16 out of 19 AML cases (84.2%). The results showed that survivin fluorescence distribution was in cytoplasm. DCs from peripheral blood mononuclear cells were successfully induced, with typical DC morphologic characteristic. The vaccination with dendritic cells pulsed with survivin antigen dramatically stimulated the proliferation of T cells. The DCs loading survivin activated T cells with higher CD4(+) T(H) ratio as compared with DCs group, T cells activated with DCs expressed CD8 and CD56. Survivin DCs significantly inhibited the growth of leukemic cells in vitro. In conclusion, survivin antigen expressed in the cytoplasm of leukemic cells, leukemic vaccination with DCs pulsed with survivin antigen in vitro inhibited the proliferation of leukemic cells, that may be a pathway for therapy of leukemia.

  19. Regulation of AMPA and NMDA receptor-mediated EPSPs in dendritic trees of thalamocortical cells.

    Science.gov (United States)

    Lajeunesse, Francis; Kröger, Helmut; Timofeev, Igor

    2013-01-01

    Two main excitatory synapses are formed at the dendritic arbor of first-order nuclei thalamocortical (TC) neurons. Ascending sensory axons primarily establish contacts at large proximal dendrites, whereas descending corticothalamic fibers form synapses on thin distal dendrites. With the use of a multicomparment computational model based on fully reconstructed TC neurons from the ventroposterolateral nucleus of the cat, we compared local responses at the site of stimulation as well as somatic responses induced by both α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- and N-methyl-D-aspartate receptor (NMDAR)-mediated currents. We found that AMPAR-mediated responses, when synapses were located at proximal dendrites, induced a larger depolarization at the level of soma, whereas NMDAR-mediated responses were more efficient for synapses located at distal dendrites. The voltage transfer and transfer impedance were higher for NMDAR than for AMPAR activation at any location. For both types of synaptic current and for both input locations at the dendritic arbor, somatic responses were characterized by a low variability despite the large variability found in local responses in dendrites. The large neurons had overall smaller somatic responses than small neurons, but this relation was not found in local dendritic responses. We conclude that in TC cells, the dendritic location of small synaptic inputs does not play a major role in the amplitude of a somatic response, but the size of the neuron does. The variability of response amplitude between cells was much larger than the variability within cells. This suggests possible functional segregation of TC neurons of different size.

  20. Fusions of Breast Carcinoma and Dendritic Cells as a Vaccine for the Treatment of Metatastic Breast Cancer

    Science.gov (United States)

    2012-07-01

    Dendritic Cells as a Vaccine for the Treatment of Metatastic Breast Cancer PRINCIPAL INVESTIGATOR: Donald Kufe, M.D...COVERED 1 July 2011 – 30 June 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Fusions of Breast Carcinoma and Dendritic Cells as a Vaccine for...have been enrolled thus far. We reported in detail the characterization of the tumor cells, the generated dendritic cells and the DC/tumor fusions

  1. 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.

  2. Contact-dependent Stimulation and Inhibition of Dendritic Cells by Natural Killer Cells

    OpenAIRE

    Piccioli, Diego; Sbrana, Silverio; Melandri, Emiliano; Valiante, Nicholas M.

    2002-01-01

    Natural killer (NK) cells and dendritic cells (DCs) are two distinct cell types of innate immunity. It is known that the in vitro interaction of human NK cells with autologous DCs results in DC lysis. Here we show that contact-dependent interactions between activated human NK cells and immature DCs (iDCs) provides a “control switch” for the immune system. At low NK/DC ratios, this interaction dramatically amplifies DC responses, whereas at high ratios it completely turns off their responses. ...

  3. On/off TLR segnaling decides immunogenic or tolerogenic dendritic cell maturation upon NKT cell contact

    OpenAIRE

    Caielli,

    2009-01-01

    Invariant Natural Killer (iNK)T cells play opposite immune functions. They participate in the innate immune response to promote anti-microbial and anti-tumor immunity and they are crucial to maintain T cell tolerance and prevent autoimmune diseases. While it is well known that the adjuvant function of iNKT cells is mediated through maturation of dendritic cells (DC), the mechanism underlying the tolerogenic function of iNKT cells remains unclear. We performed co-culture experiments with immat...

  4. 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.

  5. Dendritic cell targeting vaccine for HPV-associated cancer

    Science.gov (United States)

    Yin, Wenjie; Duluc, Dorothée; Joo, HyeMee; Oh, SangKon

    2017-01-01

    Dendritic cells (DCs) are major antigen presenting cells that can efficiently prime and activate cellular immune responses. Delivering antigens to in vivo DCs has thus been considered as a promising strategy that could allow us to mount T cell-mediated therapeutic immunity against cancers in patients. Successful development of such types of cancer vaccines that can target in vivo DCs, however, requires a series of outstanding questions that need to be addressed. These include the proper selection of which DC surface receptors, specific DC subsets and DC activators that can further enhance the efficacy of vaccines by promoting effector T cell infiltration and retention in tumors and their actions against tumors. Supplementing these areas of research with additional strategies that can counteract tumor immune evasion mechanisms is also expected to enhance the efficacy of such therapeutic vaccines against cancers. After more than a decade of study, we have concluded that antigen targeting to DCs via CD40 to evoke cellular responses is more efficient than targeting antigens to the same types of DCs via eleven other DC surface receptors tested. In recent work, we have further demonstrated that a prototype vaccine (anti-CD40-HPV16.E6/7, a recombinant fusion protein of anti-human CD40 and HPV16.E6/7 protein) for HPV16-associated cancers can efficiently activate HPV16.E6/7-specific T cells, particularly CD8+ T cells, from the blood of HPV16+ head-and-neck cancer patients. Moreover, anti-CD40-HPV16.E6/7 plus poly(I:C) can mount potent therapeutic immunity against TC-1 tumor expressing HPV16.E6/7 protein in human CD40 transgenic mice. In this manuscript, we thus highlight our recent findings for the development of novel CD40 targeting immunotherapeutic vaccines for HPV16-associated malignancies. In addition, we further discuss several of key questions that still remain to be addressed for enhancing therapeutic immunity elicited by our prototype vaccine against HPV16

  6. Frequency-dependent signal processing in apical dendrites of hippocampal CA1 pyramidal cells.

    Science.gov (United States)

    Watanabe, H; Tsubokawa, H; Tsukada, M; Aihara, T

    2014-10-10

    Depending on an animal's behavioral state, hippocampal CA1 pyramidal cells receive distinct patterns of excitatory and inhibitory synaptic inputs. The time-dependent changes in the frequencies of these inputs and the nonuniform distribution of voltage-gated channels lead to dynamic fluctuations in membrane conductance. In this study, using a whole-cell patch-clamp method, we attempted to record and analyze the frequency dependencies of membrane responsiveness in Wistar rat hippocampal CA1 pyramidal cells following noise current injection directly into dendrites and somata under pharmacological blockade of all synaptic inputs. To estimate the frequency-dependent properties of membrane potential, membrane impedance was determined from the voltage response divided by the input current in the frequency domain. The cell membrane of most neurons showed low-pass filtering properties in all regions. In particular, the properties were strongly expressed in the somata or proximal dendrites. Moreover, the data revealed nonuniform distribution of dendritic impedance, which was high in the intermediate segment of the apical dendritic shaft (∼220-260μm from the soma). The low-pass filtering properties in the apical dendrites were more enhanced by membrane depolarization than those in the somata. Coherence spectral analysis revealed high coherence between the input signal and the output voltage response in the theta-gamma frequency range, and large lags emerged in the distal dendrites in the gamma frequency range. Our results suggest that apical dendrites of hippocampal CA1 pyramidal cells integrate synaptic inputs according to the frequency components of the input signal along the dendritic segments receiving the inputs.

  7. Cigarette smoke differentially modulates dendritic cell maturation and function in time

    NARCIS (Netherlands)

    Givi, Masoumeh Ezzati; Folkerts, Gert; Wagenaar, Gerry T M; Redegeld, Frank A; Mortaz, Esmaeil

    2015-01-01

    BACKGROUND: Dendritic cells (DCs) as professional antigen presenting cells (APCs) play a critical role in the regulation of host immune responses. DCs evolve from immature, antigen-capturing cells, to mature antigen-presenting cells. The relative contribution of DCs to cigarette smoke-induced inflam

  8. 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.

  9. 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.

  10. Natural Killer cells as helper cells in Dendritic cell cancer vaccines

    Directory of Open Access Journals (Sweden)

    María Betina Pampena

    2015-01-01

    Full Text Available Vaccine-based cancer immunotherapy has generated highly variable clinical results due to differing methods of vaccine preparation and variation in patient populations, among other lesser factors. Moreover, these clinical responses do not necessarily correspond with the induction of tumor-specific cytotoxic lymphocytes. Here we review the participation of natural killer (NK cells as alternative immune components that could cooperate in successful vaccination treatment. NK cells have been described as helper cells in dendritic cell-based cancer vaccines, but the role in other kinds of vaccination strategies (whole cells, peptide or DNA- based vaccines is poorly understood. In this article we address the following issues regarding the role of NK cells in cancer vaccines: NK cell anti-tumor action sites, and the loci of NK cell interaction with other immune cells; descriptions of new data on the memory characteristics of NK cells described in infectious diseases; and finally phenotypical and functional changes after vaccination measured by immunomonitoring in preclinical and clinical settings.

  11. Biodistribution of radiolabelled human dendritic cells injected by various routes

    Energy Technology Data Exchange (ETDEWEB)

    Quillien, Veronique [Centre Regional de Lutte Contre le Cancer, Rennes (France); Centre Eugene Marquis, Unite de Therapie Cellulaire, Rennes (France); Moisan, Annick; Carsin, Andre; Lesimple, Thierry; Lefeuvre, Claudia; Bertho, Nicolas; Devillers, Anne; Toujas, Louis [Centre Regional de Lutte Contre le Cancer, Rennes (France); Adamski, Henri [CHU, Service de Dermatologie, Rennes (France); Leberre, Claudine [Etablissement Francais du Sang (EFS), Rennes (France)

    2005-07-01

    The purpose of this study was to investigate the biodistribution of mature dendritic cells (DCs) injected by various routes, during a cell therapy protocol. In the context of a vaccine therapy protocol for melanoma, DCs matured with Ribomunyl and interferon-gamma were labelled with{sup 111}In-oxine and injected into eight patients along various routes: afferent lymphatic vessel (IL) (4 times), lymph node (IN) (5 times) and intradermally (ID) (6 times). Scintigraphic investigations showed that the IL route allowed localisation of 80% of injected radioactivity in eight to ten nodes. In three cases of IN injection, the entire radioactivity stagnated in the injected nodes, while in two cases, migration to adjacent nodes was observed. This migration was detected rapidly after injection, as with IL injections, suggesting that passive transport occurred along the physiological lymphatic pathways. In two of the six ID injections, 1-2% of injected radioactivity reached a proximal lymph node. Migration was detectable in the first hour, but increased considerably after 24 h, suggesting an active migration mechanism. In both of the aforementioned cases, DCs were strongly CCR7-positive, but this feature was not a sufficient condition for effective migration. In comparison with DCs matured with TNF-{alpha}, IL-1{beta}, IL-6 and PGE2, our DCs showed a weaker in vitro migratory response to CCL21, despite comparable CCR7 expression, and higher allostimulatory and TH1 polarisation capacities. The IL route allowed reproducible administration of specified numbers of DCs. The IN route sometimes yielded fairly similar results, but not reproducibly. Lastly, we showed that DCs matured without PGE2 that have in vitro TH1 polarisation capacities can migrate to lymph nodes after ID injection. (orig.)

  12. 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.

  13. Lung Dendritic Cells Facilitate Extrapulmonary Bacterial Dissemination during Pneumococcal Pneumonia

    Directory of Open Access Journals (Sweden)

    Alva eRosendahl

    2013-06-01

    Full Text Available Streptococcus pneumoniae is a leading cause of bacterial pneumonia worldwide. Given the critical role of dendritic cells (DCs in regulating and modulating the immune response to pathogens, we investigated here the role of DCs in S. pneumoniae lung infections. Using a well-established transgenic mouse line which allows the conditional transient depletion of DCs, we showed that ablation of DCs resulted in enhanced resistance to intranasal challenge with S. pneumoniae. DC-depleted mice exhibited delayed bacterial systemic dissemination, significantly reduced bacterial loads in the infected organs and lower levels of serum inflammatory mediators than non-depleted animals. The increased resistance of DC-depleted mice to S. pneumoniae was associated with a better capacity to restrict pneumococci extrapulmonary dissemination. Furthermore, we demonstrated that S. pneumoniae disseminated from the lungs into the regional lymph nodes in a cell-independent manner and that this direct way of dissemination was much more efficient in the presence of DCs. We also provide evidence that S. pneumoniae induces expression and activation of matrix metalloproteinase-9 (MMP-9 in cultured bone marrow-derived DCs. MMP-9 is a protease involved in the breakdown of extracellular matrix proteins and is critical for DC trafficking across extracellular matrix and basement membranes during the migration from the periphery to the lymph nodes. MMP-9 was also significantly up-regulated in the lungs of mice after intranasal infection with S. pneumoniae. Notably, the expression levels of MMP-9 in the infected lungs were significantly decreased after depletion of DCs suggesting the involvement of DCs in MMP-9 production during pneumococcal pneumonia. Thus, we propose that S. pneumoniae can exploit the DC-derived proteolysis to open tissue barriers thereby facilitating its own dissemination from the local site of infection.

  14. A stepwise procedure for isolation of murine bone marrow and generation of dendritic cells

    Directory of Open Access Journals (Sweden)

    Alka Madaan

    2014-02-01

    Full Text Available Bone marrow derived Dendritic cells (BMDCs are routinely employed in cell based assays to evaluate immunomodulatory and anti-inflammatory activities. Hence, simplified, stepwise, defined and standardized methods are required for isolation of bone marrow cells from mice, propagating them in presence of growth factors and obtaining high and reproducible yields of BMDCs. Here, we describe a detailed, stepwise protocol with pictorial representation to isolate bone marrow from mouse femur and development of dendritic cells. Mouse bone marrow cells are cultured in presence of granulocyte-macrophage colony stimulating factor (GM-CSF for 6 days to generate BMDCs.

  15. Changes in dendritic cells and dendritic cell subpopulations in peripheral blood of recipients during acute rejection after kidney transplantation

    Institute of Scientific and Technical Information of China (English)

    Ma Linlin; Liu Yong; Wu Junjie; Xu Xiuhong; Liu Fen; Feng Lang; Xie Zelin

    2014-01-01

    Background Advances in transplantation immunology show that the balance between dendritic cells (DCs) and their subsets can maintain stable immune status in the induction of tolerance after transplantation.The aim of this study was to investigate if DCs and DC subpopulations in recipient peripheral blood are effective diagnostic indicators of acute rejection following kidney transplantation.Methods Immunofluorescent flow cytometry was used to classify white blood cells (WBCs),the levels of mononuclear cells and DCs (including the dominant subpopulations,plasmacytoid DC (pDC) and myeloid DC (mDC)) in peripheral blood at 0,1,7,and 28 days and 1 year after kidney transplantation in 33 patients.In addition,the blood levels of interleukin-10 (IL-10) and IL-12 were monitored before and after surgery.Fifteen healthy volunteers served as normal controls.Patients were undertaking hemodialysis owing to uremia before surgery.Results The total number of DCs,pDC,and mDC in peripheral blood and the pDC/mDC ratio were significantly lower in patients than controls (P <0.05).Peripheral DCs suddenly decreased at the end of day 1,then gradually increased through day 28 but remained below normal levels.After 1 year,levels were higher than before surgery but lower than normal.The mDC levels were higher in patients with acute rejection before and 1 day after surgery (P <0.005).There was no significant difference in IL-10 and IL-12 levels between patients with and without acute rejection.Conclusion The changes in DCs and DC subpopulations during the acute rejection period may serve as effective markers and referral indices for monitoring the immune state,and predicting rejection and reasonably adjusting immunosuppressants.

  16. Downregulation of the Syk Signaling Pathway in Intestinal Dendritic Cells Is Sufficient To Induce Dendritic Cells That Inhibit Colitis.

    Science.gov (United States)

    Hang, Long; Blum, Arthur M; Kumar, Sangeeta; Urban, Joseph F; Mitreva, Makedonka; Geary, Timothy G; Jardim, Armando; Stevenson, Mary M; Lowell, Clifford A; Weinstock, Joel V

    2016-10-01

    Helminthic infections modulate host immunity and may protect people in less-developed countries from developing immunological diseases. In a murine colitis model, the helminth Heligmosomoides polygyrus bakeri prevents colitis via induction of regulatory dendritic cells (DCs). The mechanism driving the development of these regulatory DCs is unexplored. There is decreased expression of the intracellular signaling pathway spleen tyrosine kinase (Syk) in intestinal DCs from H. polygyrus bakeri-infected mice. To explore the importance of this observation, it was shown that intestinal DCs from DC-specific Syk(-/-) mice were powerful inhibitors of murine colitis, suggesting that loss of Syk was sufficient to convert these cells into their regulatory phenotype. DCs sense gut flora and damaged epithelium via expression of C-type lectin receptors, many of which signal through the Syk signaling pathway. It was observed that gut DCs express mRNA encoding for C-type lectin (CLEC) 7A, CLEC9A, CLEC12A, and CLEC4N. H. polygyrus bakeri infection downmodulated CLEC mRNA expression in these cells. Focusing on CLEC7A, which encodes for the dectin-1 receptor, flow analysis showed that H. polygyrus bakeri decreases dectin-1 expression on the intestinal DC subsets that drive Th1/Th17 development. DCs become unresponsive to the dectin-1 agonist curdlan and fail to phosphorylate Syk after agonist stimulation. Soluble worm products can block CLEC7A and Syk mRNA expression in gut DCs from uninfected mice after a brief in vitro exposure. Thus, downmodulation of Syk expression and phosphorylation in intestinal DCs could be important mechanisms through which helminths induce regulatory DCs that limit colitis.

  17. Corticotropin-releasing factor secretion from dendritic cells stimulated by commensal bacteria

    Institute of Scientific and Technical Information of China (English)

    Mariko Hojo; Toshifumi Ohkusa; Harumi Tomeoku; Shigeo Koido; Daisuke Asaoka; Akihito Nagahara; Sumio Watanabe

    2011-01-01

    AIM: To study the production and secretion of corticotropin-releasing factor (CRF) by dendritic cells and the influence of commensal bacteria.METHODS: JAWSⅡ cells (ATCC CRL-11904), a mouse dendritic cell line, were seeded into 24-well culture plates and grown for 3 d. Commensal bacterial strains of Clostridium clostrodiiforme (JCM1291), Bacteroides vulgatus (B. vulgatus) (JCM5856), Escherichia coli (JCM1649), or Fusobacterium varium (F. varium) (ATCC8501) were added to the cells except for the control well, and incubated for 2 h. After incubation, we performed enzyme-linked immunosorbent assay for the cultured medium and reverse transcription polymerase chain reaction for the dendritic cells, and compared these values with controls.RESULTS: The level of CRF secretion by control dendritic cells was 40.4 ± 6.2 pg/mL. The CRF levels for cells incubated with F. varium and B. vulgatus were significantly higher than that of the control (P < 0.0001). CRF mRNA was present in the control sample without bacteria, and CRF mRNA levels in all samples treated with bacteria were above that of the control sample.F. varium caused the greatest increase in CRF mRNA expression. CONCLUSION: Our results suggest that dendritic cells produce CRF, a process augmented by commensal bacteria.

  18. Phenotype and polarization of autologous T cells by biomaterial-treated dendritic cells.

    Science.gov (United States)

    Park, Jaehyung; Gerber, Michael H; Babensee, Julia E

    2015-01-01

    Given the central role of dendritic cells (DCs) in directing T-cell phenotypes, the ability of biomaterial-treated DCs to dictate autologous T-cell phenotype was investigated. In this study, we demonstrate that differentially biomaterial-treated DCs differentially directed autologous T-cell phenotype and polarization, depending on the biomaterial used to pretreat the DCs. Immature DCs (iDCs) were derived from human peripheral blood monocytes and treated with biomaterial films of alginate, agarose, chitosan, hyaluronic acid, or 75:25 poly(lactic-co-glycolic acid) (PLGA), followed by co-culture of these biomaterial-treated DCs and autologous T cells. When autologous T cells were co-cultured with DCs treated with biomaterial film/antigen (ovalbumin, OVA) combinations, different biomaterial films induced differential levels of T-cell marker (CD4, CD8, CD25, CD69) expression, as well as differential cytokine profiles [interferon (IFN)-γ, interleukin (IL)-12p70, IL-10, IL-4] in the polarization of T helper (Th) types. Dendritic cells treated with agarose films/OVA induced CD4+CD25+FoxP3+ (T regulatory cells) expression, comparable to untreated iDCs, on autologous T cells in the DC-T co-culture system. Furthermore, in this co-culture, agarose treatment induced release of IL-12p70 and IL-10 at higher levels as compared with DC treatment with other biomaterial films/OVA, suggesting Th1 and Th2 polarization, respectively. Dendritic cells treated with PLGA film/OVA treatment induced release of IFN-γ at higher levels compared with that observed for co-cultures with iDCs or DCs treated with all other biomaterial films. These results indicate that DC treatment with different biomaterial films has potential as a tool for immunomodulation by directing autologous T-cell responses.

  19. Functional polarity of dendrites and axons of primate A1 amacrine cells.

    Science.gov (United States)

    Davenport, Christopher M; Detwiler, Peter B; Dacey, Dennis M

    2007-01-01

    The A1 cell is an axon-bearing amacrine cell of the primate retina with a diffusely stratified, moderately branched dendritic tree (approximately 400 microm diameter). Axons arise from proximal dendrites forming a second concentric, larger arborization (>4 mm diameter) of thin processes with bouton-like swellings along their length. A1 cells are ON-OFF transient cells that fire a brief high frequency burst of action potentials in response to light (Stafford & Dacey, 1997). It has been hypothesized that A1 cells receive local input to their dendrites, with action potentials propagating output via the axons across the retina, serving a global inhibitory function. To explore this hypothesis we recorded intracellularly from A1 cells in an in vitro macaque monkey retina preparation. A1 cells have an antagonistic center-surround receptive field structure for the ON and OFF components of the light response. Blocking the ON pathway with L-AP4 eliminated ON center responses but not OFF center responses or ON or OFF surround responses. Blocking GABAergic inhibition with picrotoxin increased response amplitudes without affecting receptive field structure. TTX abolished action potentials, with little effect on the sub-threshold light response or basic receptive field structure. We also used multi-photon laser scanning microscopy to record light-induced calcium transients in morphologically identified dendrites and axons of A1 cells. TTX completely abolished such calcium transients in the axons but not in the dendrites. Together these results support the current model of A1 function, whereby the dendritic tree receives synaptic input that determines the center-surround receptive field; and action potentials arise in the axons, which propagate away from the dendritic field across the retina.

  20. 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.