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Sample records for dendritic cell-mediated induction

  1. Neonatal Fc receptor expression in dendritic cells mediates protective immunity against colorectal cancer.

    PubMed

    Baker, Kristi; Rath, Timo; Flak, Magdalena B; Arthur, Janelle C; Chen, Zhangguo; Glickman, Jonathan N; Zlobec, Inti; Karamitopoulou, Eva; Stachler, Matthew D; Odze, Robert D; Lencer, Wayne I; Jobin, Christian; Blumberg, Richard S

    2013-12-12

    Cancers arising in mucosal tissues account for a disproportionately large fraction of malignancies. Immunoglobulin G (IgG) and the neonatal Fc receptor for IgG (FcRn) have an important function in the mucosal immune system that we have now shown extends to the induction of CD8(+) T cell-mediated antitumor immunity. We demonstrate that FcRn within dendritic cells (DCs) was critical for homeostatic activation of mucosal CD8(+) T cells that drove protection against the development of colorectal cancers and lung metastases. FcRn-mediated tumor protection was driven by DCs activation of endogenous tumor-reactive CD8(+) T cells via the cross-presentation of IgG complexed antigens (IgG IC), as well as the induction of cytotoxicity-promoting cytokine secretion, particularly interleukin-12, both of which were independently triggered by the FcRn-IgG IC interaction in murine and human DCs. FcRn thus has a primary role within mucosal tissues in activating local immune responses that are critical for priming efficient anti-tumor immunosurveillance.

  2. Dendritic Cell-Mediated In Vivo Bone Resorption

    PubMed Central

    Maitra, Radhashree; Follenzi, Antonia; Yaghoobian, Arash; Montagna, Cristina; Merlin, Simone; Cannizzo, Elvira S.; Hardin, John A.; Cobelli, Neil; Stanley, E. Richard; Santambrogio, Laura

    2013-01-01

    Osteoclasts are resident cells of the bone that are primarily involved in the physiological and pathological remodeling of this tissue. Mature osteoclasts are multinucleated giant cells that are generated from the fusion of circulating precursors originating from the monocyte/macrophage lineage. During inflammatory bone conditions in vivo, de novo osteoclastogenesis is observed but it is currently unknown whether, besides increased osteoclast differentiation from undifferentiated precursors, other cell types can generate a multinucleated giant cell phenotype with bone resorbing activity. In this study, an animal model of calvaria-induced aseptic osteolysis was used to analyze possible bone resorption capabilities of dendritic cells (DCs). We determined by FACS analysis and confocal microscopy that injected GFP-labeled immature DCs were readily recruited to the site of osteolysis. Upon recruitment, the cathepsin K-positive DCs were observed in bone-resorbing pits. Additionally, chromosomal painting identified nuclei from female DCs, previously injected into a male recipient, among the nuclei of giant cells at sites of osteolysis. Finally, osteolysis was also observed upon recruitment of CD11c-GFP conventional DCs in Csf1r–/– mice, which exhibit a severe depletion of resident osteoclasts and tissue macrophages. Altogether, our analysis indicates that DCs may have an important role in bone resorption associated with various inflammatory diseases. PMID:20581147

  3. Comparison of dendritic cell-mediated immune responses among canine malignant cells.

    PubMed

    Tamura, Kyoichi; Arai, Hiroyoshi; Ueno, Emi; Saito, Chie; Yagihara, Hiroko; Isotani, Mayu; Ono, Kenichiro; Washizu, Tsukimi; Bonkobara, Makoto

    2007-09-01

    Dendritic cell (DC) vaccination is one of the most attractive immunotherapies for malignancies in dogs. To examine the differences in DC-mediated immune responses from different types of malignancies in dogs, we vaccinated dogs using autologous DCs pulsed with keyhole limpet hemocyanin (KLH) and cell lysate prepared from squamous cell carcinoma SCC2/88 (SCC-KLH-DC), histiocytic sarcoma CHS-5 (CHS-KLH-DC), or B cell leukemia GL-1 (GL-KLH-DC) in vitro. In vivo inductions of immune responses against these tumor cells were compared by the delayed-type hypersensitivity (DTH) skin test. The DTH response against SCC2/88 cells were observed in dogs vaccinated with autologous SCC-KLH-DC, while the response was undetectable against CHS-5 and GL-1 cells in dogs vaccinated with autologous CHS-KLH-DC and GL-KLH-DC. Skin biopsies taken from DTH challenge sites were then examined for immunohistochemistry, and recruitment of CD8 and CD4 T cells was detected at the site where SCC2/88 cells were inoculated in dogs vaccinated with SCC-KLH-DC. By contrast, neither CD8 nor CD4 T cell infiltration was found at the DTH challenge site in the dogs vaccinated with CHS-KLH-DC or GL-KLH-DC. These findings may reflect that the efficacy of immune induction by DC vaccination varies among tumor types and that immune responses could be inducible in squamous cell carcinoma. Our results encouraged further investigation of therapeutic vaccination for dogs with advanced squamous cell carcinoma in clinical trials.

  4. Dendritic Cell-Mediated Phagocytosis but Not Immune Activation Is Enhanced by Plasmin

    PubMed Central

    Borg, Rachael J.; Samson, Andre L.; Au, Amanda E.-L.; Scholzen, Anja; Fuchsberger, Martina; Kong, Ying Y.; Freeman, Roxann; Mifsud, Nicole A.; Plebanski, Magdalena; Medcalf, Robert L.

    2015-01-01

    Removal of dead cells in the absence of concomitant immune stimulation is essential for tissue homeostasis. We recently identified an injury-induced protein misfolding event that orchestrates the plasmin-dependent proteolytic degradation of necrotic cells. As impaired clearance of dead cells by the innate immune system predisposes to autoimmunity, we determined whether plasmin could influence endocytosis and immune cell stimulation by dendritic cells – a critical cell that links the innate and adaptive immune systems. We find that plasmin generated on the surface of necrotic cells enhances their phagocytic removal by human monocyte-derived dendritic cells. Plasmin also promoted phagocytosis of protease-resistant microparticles by diverse mouse dendritic cell sub-types both in vitro and in vivo. Together with an increased phagocytic capacity, plasmin-treated dendritic cells maintain an immature phenotype, exhibit reduced migration to lymph nodes, increase their expression/release of the immunosuppressive cytokine TGF-β, and lose their capacity to mount an allogeneic response. Collectively, our findings support a novel role for plasmin formed on dead cells and other phagocytic targets in maintaining tissue homeostasis by increasing the phagocytic function of dendritic cells while simultaneously decreasing their immunostimulatory capacity consistent with producing an immunosuppressive state. PMID:26132730

  5. Monocyte-derived inflammatory Langerhans cells and dermal dendritic cells mediate psoriasis-like inflammation

    PubMed Central

    Singh, Tej Pratap; Zhang, Howard H.; Borek, Izabela; Wolf, Peter; Hedrick, Michael N.; Singh, Satya P.; Kelsall, Brian L.; Clausen, Bjorn E.; Farber, Joshua M.

    2016-01-01

    Dendritic cells (DCs) have been implicated in the pathogenesis of psoriasis but the roles for specific DC subsets are not well defined. Here we show that DCs are required for psoriasis-like changes in mouse skin induced by the local injection of IL-23. However, Flt3L-dependent DCs and resident Langerhans cells are dispensable for the inflammation. In epidermis and dermis, the critical DCs are TNF-producing and IL-1β-producing monocyte-derived DCs, including a population of inflammatory Langerhans cells. Depleting Ly6Chi blood monocytes reduces DC accumulation and the skin changes induced either by injecting IL-23 or by application of the TLR7 agonist imiquimod. Moreover, we find that IL-23-induced inflammation requires expression of CCR6 by DCs or their precursors, and that CCR6 mediates monocyte trafficking into inflamed skin. Collectively, our results imply that monocyte-derived cells are critical contributors to psoriasis through production of inflammatory cytokines that augment the activation of skin T cells. PMID:27982014

  6. In vitro enhancement of dendritic cell-mediated anti-glioma immune response by graphene oxide

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Li, Zhongjun; Duan, Jinhong; Wang, Chen; Fang, Ying; Yang, Xian-Da

    2014-06-01

    Malignant glioma has extremely poor prognosis despite combination treatments with surgery, radiation, and chemotherapy. Dendritic cell (DC)-based immunotherapy may potentially serve as an adjuvant treatment of glioma, but its efficacy generally needs further improvement. Here we explored whether graphene oxide (GO) nanosheets could modulate the DC-mediated anti-glioma immune response in vitro, using the T98G human glioma cell line as the study model. Pulsing DCs with a glioma peptide antigen (Ag) generated a limited anti-glioma response compared to un-pulsed DCs. Pulsing DCs with GO alone failed to produce obvious immune modulation effects. However, stimulating DCs with a mixture of GO and Ag (GO-Ag) significantly enhanced the anti-glioma immune reaction ( p < 0.05). The secretion of interferon gamma (IFN-γ) by the lymphocytes was also markedly boosted by GO-Ag. Additionally, the anti-glioma immune response induced by GO-Ag appeared to be target-specific. Furthermore, at the concentration used in this study, GO exhibited a negligible effect on the viability of the DCs. These results suggested that GO might have potential utility for boosting a DC-mediated anti-glioma immune response.

  7. Role of Glycosphingolipids in Dendritic Cell-Mediated HIV-1 Trans-infection

    PubMed Central

    Puryear, Wendy Blay

    2013-01-01

    Glycosphingolipids (GSLs) are components of the cell membrane that comprise a membrane bound lipid, ceramide, coupled to an extracellular carbohydrate. GSLs impact numerous aspects of membrane biology, including membrane fluidity, curvature, and organization. The role of these molecules in both chronic inflammation and infectious disease and underlying pathogenic mechanisms are just starting to be recognized. As a component of the cell membrane, GSLs are also incorporated into lipid bilayers of diverse enveloped viruses as they bud out from the host cell and can go on to have a significant influence on viral pathogenesis. Dendritic cell (DC) subsets located in the peripheral mucosal tissues are proposed to be one of the earliest cell types that encounter transmitted viruses and help initiate adaptive immune responses against the invading pathogen by interacting with T cells. In turn, viruses, as obligatory intracellular parasites, rely on host cells for completing their replication cycle, and not surprisingly, HIV has evolved to exploit DC biology for the initial transmission event as well as for its dissemination and propagation within the infected host. In this review, we describe the mechanisms by which GSLs impact DC-mediated HIV trans-infection by either modulating virus infectivity, serving as a direct virus particle-associated host-derived ligand for specific interactions with DCs, or modulating the T cell membrane in such a way as to impact viral entry and thereby productive infection of CD4+ T cells. PMID:22975874

  8. Dendritic cell-mediated immune humanization of mice: implications for allogeneic and xenogeneic stem cell transplantation.

    PubMed

    Salguero, Gustavo; Daenthanasanmak, Anusara; Münz, Christian; Raykova, Ana; Guzmán, Carlos A; Riese, Peggy; Figueiredo, Constanca; Länger, Florian; Schneider, Andreas; Macke, Laura; Sundarasetty, Bala Sai; Witte, Torsten; Ganser, Arnold; Stripecke, Renata

    2014-05-15

    De novo regeneration of immunity is a major problem after allogeneic hematopoietic stem cell transplantation (HCT). HCT modeling in severely compromised immune-deficient animals transplanted with human stem cells is currently limited because of incomplete maturation of lymphocytes and scarce adaptive responses. Dendritic cells (DC) are pivotal for the organization of lymph nodes and activation of naive T and B cells. Human DC function after HCT could be augmented with adoptively transferred donor-derived DC. In this study, we demonstrate that adoptive transfer of long-lived human DC coexpressing high levels of human IFN-α, human GM-CSF, and a clinically relevant Ag (CMV pp65 protein) promoted human lymphatic remodeling in immune-deficient NOD.Rag1(-/-).IL-2rγ(-/-) mice transplanted with human CD34(+) cells. After immunization, draining lymph nodes became replenished with terminally differentiated human follicular Th cells, plasma B cells, and memory helper and cytotoxic T cells. Human Igs against pp65 were detectable in plasma, demonstrating IgG class-switch recombination. Human T cells recovered from mice showed functional reactivity against pp65. Adoptive immunotherapy with engineered DC provides a novel strategy for de novo immune reconstitution after human HCT and a practical and effective tool for studying human lymphatic regeneration in vivo in immune deficient xenograft hosts.

  9. Layers of dendritic cell-mediated T cell tolerance, their regulation and the prevention of autoimmunity

    PubMed Central

    Mayer, Christian T.; Berod, Luciana; Sparwasser, Tim

    2012-01-01

    The last decades of Nobel prize-honored research have unequivocally proven a key role of dendritic cells (DCs) at controlling both T cell immunity and tolerance. A tight balance between these opposing DC functions ensures immune homeostasis and host integrity. Its perturbation could explain pathological conditions such as the attack of self tissues, chronic infections, and tumor immune evasion. While recent insights into the complex DC network help to understand the contribution of individual DC subsets to immunity, the tolerogenic functions of DCs only begin to emerge. As these consist of many different layers, the definition of a “tolerogenic DC” is subjected to variation. Moreover, the implication of DCs and DC subsets in the suppression of autoimmunity are incompletely resolved. In this review, we point out conceptual controversies and dissect the various layers of DC-mediated T cell tolerance. These layers include central tolerance, Foxp3+ regulatory T cells (Tregs), anergy/deletion and negative feedback regulation. The mode and kinetics of antigen presentation is highlighted as an additional factor shaping tolerance. Special emphasis is given to the interaction between layers of tolerance as well as their differential regulation during inflammation. Furthermore, potential technical caveats of DC depletion models are considered. Finally, we summarize our current understanding of DC-mediated tolerance and its role for the suppression of autoimmunity. Understanding the mechanisms of DC-mediated tolerance and their complex interplay is fundamental for the development of selective therapeutic strategies, e.g., for the modulation of autoimmune responses or for the immunotherapy of cancer. PMID:22783257

  10. Layers of dendritic cell-mediated T cell tolerance, their regulation and the prevention of autoimmunity.

    PubMed

    Mayer, Christian T; Berod, Luciana; Sparwasser, Tim

    2012-01-01

    The last decades of Nobel prize-honored research have unequivocally proven a key role of dendritic cells (DCs) at controlling both T cell immunity and tolerance. A tight balance between these opposing DC functions ensures immune homeostasis and host integrity. Its perturbation could explain pathological conditions such as the attack of self tissues, chronic infections, and tumor immune evasion. While recent insights into the complex DC network help to understand the contribution of individual DC subsets to immunity, the tolerogenic functions of DCs only begin to emerge. As these consist of many different layers, the definition of a "tolerogenic DC" is subjected to variation. Moreover, the implication of DCs and DC subsets in the suppression of autoimmunity are incompletely resolved. In this review, we point out conceptual controversies and dissect the various layers of DC-mediated T cell tolerance. These layers include central tolerance, Foxp3(+) regulatory T cells (Tregs), anergy/deletion and negative feedback regulation. The mode and kinetics of antigen presentation is highlighted as an additional factor shaping tolerance. Special emphasis is given to the interaction between layers of tolerance as well as their differential regulation during inflammation. Furthermore, potential technical caveats of DC depletion models are considered. Finally, we summarize our current understanding of DC-mediated tolerance and its role for the suppression of autoimmunity. Understanding the mechanisms of DC-mediated tolerance and their complex interplay is fundamental for the development of selective therapeutic strategies, e.g., for the modulation of autoimmune responses or for the immunotherapy of cancer.

  11. Genetic vaccines to potentiate the effective CD103+ dendritic cell-mediated cross-priming of antitumor immunity.

    PubMed

    Zhang, Yi; Chen, Guo; Liu, Zuqiang; Tian, Shenghe; Zhang, Jiying; Carey, Cara D; Murphy, Kenneth M; Storkus, Walter J; Falo, Louis D; You, Zhaoyang

    2015-06-15

    The development of effective cancer vaccines remains an urgent, but as yet unmet, clinical need. This deficiency is in part due to an incomplete understanding of how to best invoke dendritic cells (DC) that are crucial for the induction of tumor-specific CD8(+) T cells capable of mediating durable protective immunity. In this regard, elevated expression of the transcription factor X box-binding protein 1 (XBP1) in DC appears to play a decisive role in promoting the ability of DC to cross-present Ags to CD8(+) T cells in the therapeutic setting. Delivery of DNA vaccines encoding XBP1 and tumor Ag to skin DC resulted in increased IFN-α production by plasmacytoid DC (pDC) from skin/tumor draining lymph nodes and the cross-priming of Ag-specific CD8(+) T cell responses associated with therapeutic benefit. Antitumor protection was dependent on cross-presenting Batf3(+) DC, pDC, and CD8(+) T cells. CD103(+) DC from the skin/tumor draining lymph nodes of the immunized mice appeared responsible for activation of Ag-specific naive CD8(+) T cells, but were dependent on pDC for optimal effectiveness. Similarly, human XBP1 improved the capacity of human blood- and skin-derived DC to activate human T cells. These data support an important intrinsic role for XBP1 in DC for effective cross-priming and orchestration of Batf3(+) DC-pDC interactions, thereby enabling effective vaccine induction of protective antitumor immunity.

  12. Synthetic long peptide-based vaccine formulations for induction of cell mediated immunity: A comparative study of cationic liposomes and PLGA nanoparticles.

    PubMed

    Varypataki, Eleni Maria; Silva, Ana Luisa; Barnier-Quer, Christophe; Collin, Nicolas; Ossendorp, Ferry; Jiskoot, Wim

    2016-03-28

    Nanoparticulate formulations for synthetic long peptide (SLP)-cancer vaccines as alternative to clinically used Montanide ISA 51- and squalene-based emulsions are investigated in this study. SLPs were loaded into TLR ligand-adjuvanted cationic liposomes and PLGA nanoparticles (NPs) to potentially induce cell-mediated immune responses. The liposomal and PLGA NP formulations were successfully loaded with up to four different compounds and were able to enhance antigen uptake by dendritic cells (DCs) and subsequent activation of T cells in vitro. Subcutaneous vaccination of mice with the different formulations showed that the SLP-loaded cationic liposomes were the most efficient for the induction of functional antigen-T cells in vivo, followed by PLGA NPs which were as potent as or even more than the Montanide and squalene emulsions. Moreover, after transfer of antigen-specific target cells in immunized mice, liposomes induced the highest in vivo killing capacity. These findings, considering also the inadequate safety profile of the currently clinically used adjuvant Montanide ISA-51, make these two particulate, biodegradable delivery systems promising candidates as delivery platforms for SLP-based immunotherapy of cancer.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Oral-nasopharyngeal dendritic cells mediate T cell-independent IgA class switching on B-1 B cells.

    PubMed

    Kataoka, Kosuke; Fujihashi, Keiko; Terao, Yutaka; Gilbert, Rebekah S; Sekine, Shinichi; Kobayashi, Ryoki; Fukuyama, Yoshiko; Kawabata, Shigetada; Fujihashi, Kohtaro

    2011-01-01

    Native cholera toxin (nCT) as a nasal adjuvant was shown to elicit increased levels of T-independent S-IgA antibody (Ab) responses through IL-5- IL-5 receptor interactions between CD4+ T cells and IgA+ B-1 B cells in murine submandibular glands (SMGs) and nasal passages (NPs). Here, we further investigate whether oral-nasopharyngeal dendritic cells (DCs) play a central role in the induction of B-1 B cell IgA class switch recombination (CSR) for the enhancement of T cell-independent (TI) mucosal S-IgA Ab responses. High expression levels of activation-induced cytidine deaminase, Iα-Cμ circulation transcripts and Iμ-Cα transcripts were seen on B-1 B cells purified from SMGs and NPs of both TCRβ⁻/⁻ mice and wild-type mice given nasal trinitrophenyl (TNP)-LPS plus nCT, than in the same tissues of mice given nCT or TNP-LPS alone. Further, DCs from SMGs, NPs and NALT of mice given nasal TNP-LPS plus nCT expressed significantly higher levels of a proliferation-inducing ligand (APRIL) than those in mice given TNP-LPS or nCT alone, whereas the B-1 B cells in SMGs and NPs showed elevated levels of transmembrane activator and calcium modulator cyclophilin ligand interactor (TACI) expression. Interestingly, high frequencies of IgA+ B-1 B cells were induced when peritoneal IgA⁻ IgM+ B cells were stimulated with mucosal DCs from mice given nasal TNP-LPS plus nCT. Taken together, these findings show that nasal nCT plays a key role in the enhancement of mucosal DC-mediated TI IgA CSR by B-1 B cells through their interactions with APRIL and TACI.

  15. The Role of Cell-Mediated Immunity in the Induction of Inflammatory Responses

    PubMed Central

    Cohen, Stanley

    1977-01-01

    Reactions of cell-mediated immunity fall into two broad categories: those that involve direct participation of intact lymphocytes in the effector mechanism of the reaction and those that involve mediation by soluble lymphocyte-derived factors known as lymphokines. The first kind of reaction is essentially limited to lymphocyte-dependent cytotoxicity, although certain aspects of T cell-B cell cooperation may fall into this category as well. The second category appears to comprise the bulk of the so-called cell-mediated immune response and provides a link between this system and the inflammatory system. Various lymphokines have been shown to exert profound influence upon inflammatory cell metabolism, cell surface properties, patterns of cell migration, and the activation of cells for various biologic activities involved in host defense. Although substantial information is now available about various physicochemical as well as biologic properties of lymphokines, purification and characterization data are as yet too incomplete to allow us to ascribe all of these activities to discrete mediator molecules. Current work involving the development of antibody-based techniques for mediator assay may shed light on this issue. Information on the kinds of cells capable of lymphokine production is now available. Contrary to prior expectation, T cells are not unique in their capacity for lymphokine production. Under appropriate circumstances, B cells and even nonlymphoid cells can do so as well. The unique property of lymphocytes in this regard appears to relate to their ability to respond to certain specialized signals such as specific antigen or an appropriate mitogen. Mediator production per se may represent a general biologic phenomenon. Although lymphokines have been defined mainly in terms of in vitro assays, early speculations about their in vivo importance are proving correct. Evidence for the role of lymphokines comes from studies involving detection of lymphokines in

  16. Dendritic cell-derived IL-15 controls the induction of CD8 T cell immune responses.

    PubMed

    Rückert, René; Brandt, Katja; Bulanova, Elena; Mirghomizadeh, Farhad; Paus, Ralf; Bulfone-Paus, Silvia

    2003-12-01

    The development and the differentiation of CD8(+) T cells are dependent on IL-15. Here, we have studied the source and mechanism of how IL-15 modulates CD8(+) T cell-mediated Th1 immune responses by employing two delayed-type hypersensitivity (DTH) models. IL-15-deficient (IL-15(-/-)) mice or mice treated with soluble IL-15Ralpha as an IL-15 antagonist showed significantly reduced CD8(+) T cell-dependent DTH responses, while activation of CD4(+) T cell and B cell functions remained unaffected. Injection of antigen-labeled dendritic cells (DC) from IL-15(+/+), IL-15(-/-) or IL-15Ralpha(-/-) mice revealed that DC-derived IL-15 is an absolute requirement for the initiation of DTH response. The re-establishment of the interaction of IL-15 with the IL-15Ralpha by incubating IL-15(-/-) DC with IL-15 completely restored the capacity to prime T cells for DTH induction in vivo. Moreover, IL-15 also enhanced secretion of pro-inflammatory cytokines by DC and triggered in vitro CD8(+) T cell proliferation and IL-2 release. Taken together, the data suggest that an autocrine IL-15/IL-15Ralpha signaling loop in DC is essential for inducing CD8(+)-dependent Th1 immune responses in mice. Therefore, targeted manipulation of this loop promises to be an effective, novel strategy for therapeutic modulation of clinically relevant DTH reactions.

  17. Conventional and monocyte-derived CD11b(+) dendritic cells initiate and maintain T helper 2 cell-mediated immunity to house dust mite allergen.

    PubMed

    Plantinga, Maud; Guilliams, Martin; Vanheerswynghels, Manon; Deswarte, Kim; Branco-Madeira, Filipe; Toussaint, Wendy; Vanhoutte, Leen; Neyt, Katrijn; Killeen, Nigel; Malissen, Bernard; Hammad, Hamida; Lambrecht, Bart N

    2013-02-21

    Dendritic cells (DCs) are crucial for mounting allergic airway inflammation, but it is unclear which subset of DCs performs this task. By using CD64 and MAR-1 staining, we reliably separated CD11b(+) monocyte-derived DCs (moDCs) from conventional DCs (cDCs) and studied antigen uptake, migration, and presentation assays of lung and lymph node (LN) DCs in response to inhaled house dust mite (HDM). Mainly CD11b(+) cDCs but not CD103(+) cDCs induced T helper 2 (Th2) cell immunity in HDM-specific T cells in vitro and asthma in vivo. Studies in Flt3l(-/-) mice, lacking all cDCs, revealed that moDCs were also sufficient to induce Th2 cell-mediated immunity but only when high-dose HDM was given. The main function of moDCs was the production of proinflammatory chemokines and allergen presentation in the lung during challenge. Thus, we have identified migratory CD11b(+) cDCs as the principal subset inducing Th2 cell-mediated immunity in the LN, whereas moDCs orchestrate allergic inflammation in the lung.

  18. Dendritic Cell-Mediated T Cell Proliferation -A Functional Bioindicator of Inflammatory Source-Specific Particulate Matter

    EPA Science Inventory

    Previously we found that dendritic cells (DC) were sensitive functional bioindicators of ambient PM (APM) exposure mediating Th2-allergic inflammation in the draining lymph nodes. Here, the ability of bone-marrow-derived DC (DC) and putative BM-derived basophils (Ba) to present a...

  19. Myeloid-derived suppressor cells mediate tolerance induction in autoimmune disease.

    PubMed

    Wegner, Anja; Verhagen, Johan; Wraith, David C

    2017-01-31

    In multiple sclerosis (MS) T cells aberrantly recognize self-peptides of the myelin sheath and attack the central nervous system (CNS). Antigen-specific peptide immunotherapy, which aims to restore tolerance while avoiding the use of non-specific immunosuppressive drugs, is a promising approach to combat autoimmune disease, but the cellular mechanisms behind successful therapy remain poorly understood. Myeloid-derived suppressor cells (MDSCs) have been studied intensively in the field of cancer and to a lesser extent in autoimmunity. Because of their suppressive effect on the immune system in cancer, we hypothesized that the development of MDSCs and their interaction with CD4(+) T cells could be beneficial for antigen-specific immunotherapy. Hence, changes in the quantity, phenotype and function of MDSCs during tolerance induction in our model of MS were evaluated. We reveal, for the first time, an involvement of a subset of MDSCs, known as polymorphonuclear (PMN)-MDSCs, in the process of tolerance induction. PMN-MDSCs were shown to adopt a more suppressive phenotype during peptide immunotherapy and inhibit CD4(+) T-cell proliferation in a cell-contact-dependent manner, mediated by arginase-1. Moreover, increased numbers of tolerogenic PMN-MDSCs, such as observed over the course of peptide immunotherapy, were demonstrated to provide protection from disease in a model of experimental autoimmune encephalomyelitis.

  20. Cytokine induction during T-cell-mediated clearance of mouse hepatitis virus from neurons in vivo.

    PubMed Central

    Pearce, B D; Hobbs, M V; McGraw, T S; Buchmeier, M J

    1994-01-01

    To investigate the mechanism by which viruses are cleared from neurons in the central nervous system, we have utilized a mouse model involving infection with a neurotropic variant of mouse hepatitis virus (OBLV60). After intranasal inoculation, OBLV60 grew preferentially in the olfactory bulbs of BALB/c mice. Using in situ hybridization, we found that viral RNA localized primarily in the outer layers of the olfactory bulb, including neurons of the mitral cell layer. Virus was cleared rapidly from the olfactory bulb between 5 and 11 days. Athymic nude mice failed to eliminate the virus, demonstrating a requirement for T lymphocytes. Immunosuppression of normal mice with cyclophosphamide also prevented clearance. Both CD4+ and CD8+ T-cell subsets were important, as depletion of either of these subsets delayed viral clearance. Gliosis and infiltrates of CD4+ and CD8+ cells were detected by immunohistochemical analysis at 6 days. The role of cytokines in clearance was investigated by using an RNase protection assay for interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, tumor necrosis factor alpha (TNF-alpha), TNF-beta, and gamma interferon (IFN-gamma). In immunocompetent mice there was upregulation of RNA for IL-1 alpha, IL-1 beta, IL-6, TNF-alpha, and IFN-gamma at the time of clearance. Nude mice had comparable increases in these cytokine messages, with the exception of IFN-gamma. Induction of major histocompatibility complex class I (MHC-I) molecules on cells in infected brains was demonstrated by immunohistochemical analyses in normal and nude mice, suggesting that IFN-gamma may not be necessary for induction of MHC-I on neural cells in vivo. Images PMID:8057431

  1. Rhamnogalacturonan II is a Toll-like receptor 4 agonist that inhibits tumor growth by activating dendritic cell-mediated CD8+ T cells.

    PubMed

    Park, Sung Nam; Noh, Kyung Tae; Jeong, Young-Il; Jung, In Duk; Kang, Hyun Kyu; Cha, Gil Sun; Lee, Su Jung; Seo, Jong Keun; Kang, Dae Hwan; Hwang, Tae-Ho; Lee, Eun Kyung; Kwon, Byungsuk; Park, Yeong-Min

    2013-02-08

    We evaluated the effectiveness of rhamnogalacturonan II (RG-II)-stimulated bone marrow-derived dendritic cells (BMDCs) vaccination on the induction of antitumor immunity in a mouse lymphoma model using EG7-lymphoma cells expressing ovalbumin (OVA). BMDCs treated with RG-II had an activated phenotype. RG-II induced interleukin (IL)-12, IL-1β, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) production during dendritic cell (DC) maturation. BMDCs stimulated with RG-II facilitate the proliferation of CD8+ T cells. Using BMDCs from the mice deficient in Toll-like receptors (TLRs), we revealed that RG-II activity is dependent on TLR4. RG-II showed a preventive effect of immunization with OVA-pulsed BMDCs against EG7 lymphoma. These results suggested that RG-II expedites the DC-based immune response through the TLR4 signaling pathway.

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

    PubMed Central

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

    2016-01-01

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

  3. C-type lectin-like receptor LOX-1 promotes dendritic cell-mediated class-switched B cell responses.

    PubMed

    Joo, HyeMee; Li, Dapeng; Dullaers, Melissa; Kim, Tae-Whan; Duluc, Dorothee; Upchurch, Katherine; Xue, Yaming; Zurawski, Sandy; Le Grand, Roger; Liu, Yong-Jun; Kuroda, Marcelo; Zurawski, Gerard; Oh, SangKon

    2014-10-16

    Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a pattern-recognition receptor for a variety of endogenous and exogenous ligands. However, LOX-1 function in the host immune response is not fully understood. Here, we report that LOX-1 expressed on dendritic cells (DCs) and B cells promotes humoral responses. On B cells LOX-1 signaling upregulated CCR7, promoting cellular migration toward lymphoid tissues. LOX-1 signaling on DCs licensed the cells to promote B cell differentiation into class-switched plasmablasts and led to downregulation of chemokine receptor CXCR5 and upregulation of chemokine receptor CCR10 on plasmablasts, enabling their exit from germinal centers and migration toward local mucosa and skin. Finally, we found that targeting influenza hemagglutinin 1 (HA1) subunit to LOX-1 elicited HA1-specific protective antibody responses in rhesus macaques. Thus, LOX-1 expressed on B cells and DC cells has complementary functions to promote humoral immune responses.

  4. p38 MAPK-inhibited dendritic cells induce superior antitumor immune responses and overcome regulatory T cell-mediated immunosuppression

    PubMed Central

    Lu, Yong; Zhang, Mingjun; Wang, Siqing; Hong, Bangxing; Wang, Zhiqiang; Li, Haiyan; Zheng, Yuhuan; Yang, Jing; Davis, Richard E.; Qian, Jianfei; Hou, Jian; Yi, Qing

    2014-01-01

    Dendritic cell (DC)-based cancer immunotherapy is a promising method but so far has demonstrated limited clinical benefits. Regulatory T cells (Treg) represent a major obstacle to cancer immunotherapy approaches. Here we show that inhibiting p38 MAPK during DC differentiation enables DCs to activate tumor-specific effector T cells (Teff), inhibiting the conversion of Treg and compromising Treg inhibitory effects on Teff. Inhibition of p38 MAPK in DCs lowers expression of PPARγ, activating p50 and upregulation of OX40L expression in DCs. OX40L/OX40 interactions between DCs and Teff and/or Treg are critical for priming effective and therapeutic antitumor responses. Similarly, p38 MAPK inhibition also augments the T cell-stimulatory capacity of human monocyte-derived DCs in the presence of Treg. These findings contribute to ongoing efforts to improve DC-based immunotherapy in human cancers. PMID:24957461

  5. The molecule of DC-SIGN captures enterovirus 71 and confers dendritic cell-mediated viral trans-infection

    PubMed Central

    2014-01-01

    Background Enterovirus 71 (EV71) is the main causative agent of hand, foot and mouth disease that occurs in young children. Neither antiviral agents nor vaccines are available for efficiently combating viral infection. Study of EV71–host interplay is important for understanding viral infection and developing strategies for prevention and therapy. Here the interactions of EV71 with human dendritic cells were analyzed. Methods EV71 capture, endocytosis, infection, and degradation in monocyte-derived dendritic cells (MDDCs) were detected by Flow cytometry or real-time (RT-) PCR, and MDDCs-mediated EV71 trans-infection of RD cells was determined via coculture system. Cell morphology or viability was monitored with microscopy or flow cytometry. SiRNA interference was used to knock down gene expression. Results MDDCs can bind EV71, but these loaded-EV71 particles in MDDCs underwent a rapid degradation in the absence of efficient replication; once the captured EV71 encountered susceptible cells, MDDCs efficiently transferred surface-bound viruses to target cells. The molecule of DC-SIGN (DC-specific intercellular adhesion molecule-3 grabbing nonintegrin) mediated viral binding and transfer, because interference of DC-SIGN expression with specific siRNAs reduced EV71 binding and impaired MDDC-mediated viral trans-infection, and exogenous expression of DC-SIGN molecule on Raji cell initiated viral binding and subsequent transmission. Conclusion MDDCs could bind efficiently EV71 viruses through viral binding to DC-SIGN molecule, and these captured-viruses could be transferred to susceptible cells for robust infection. The novel finding of DC-mediated EV71 dissemination might facilitate elucidation of EV71 primary infection and benefit searching for new clues for preventing viruses from initial infection. PMID:24620896

  6. 4-Tertiary butyl phenol exposure sensitizes human melanocytes to dendritic cell-mediated killing: relevance to vitiligo.

    PubMed

    Kroll, Tara M; Bommiasamy, Hemamalini; Boissy, Raymond E; Hernandez, Claudia; Nickoloff, Brian J; Mestril, Ruben; Caroline Le Poole, I

    2005-04-01

    The trigger initiating an autoimmune response against melanocytes in vitiligo remains unclear. Patients frequently experience stress to the skin prior to depigmentation. 4-tertiary butyl phenol (4-TBP) was used as a model compound to study the effects of stress on melanocytes. Heat shock protein (HSP)70 generated and secreted in response to 4-TBP was quantified. The protective potential of stress proteins generated following 4-TBP exposure was examined. It was studied whether HSP70 favors dendritic cell (DC) effector functions as well. Melanocytes were more sensitive to 4-TBP than fibroblasts, and HSP70 generated in response to 4-TBP exposure was partially released into the medium by immortalized vitiligo melanocyte cell line PIG3V. Stress protein HSP70 in turn induced membrane tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression and activation of DC effector functions towards stressed melanocytes. Melanocytes exposed to 4-TBP demonstrated elevated TRAIL death receptor expression. DC effector functions were partially inhibited by blocking antibodies to TRAIL. TRAIL expression and infiltration by CD11c+ cells was abundant in perilesional vitiligo skin. Stressed melanocytes may mediate DC activation through release of HSP70, and DC effector functions appear to play a previously unappreciated role in progressive vitiligo.

  7. NK cells modulate the lung dendritic cell-mediated Th1/Th17 immunity during intracellular bacterial infection.

    PubMed

    Shekhar, Sudhanshu; Peng, Ying; Gao, Xiaoling; Joyee, Antony G; Wang, Shuhe; Bai, Hong; Zhao, Lei; Yang, Jie; Yang, Xi

    2015-10-01

    The impact of the interaction between NK cells and lung dendritic cells (LDCs) on the outcome of respiratory infections is poorly understood. In this study, we investigated the effect and mechanism of NK cells on the function of LDCs during intracellular bacterial lung infection of Chlamydia muridarum in mice. We found that the naive mice receiving LDCs from C. muridarum-infected NK-cell-depleted mice (NK-LDCs) showed more serious body weight loss, bacterial burden, and pathology upon chlamydial challenge when compared with the recipients of LDCs from infected sham-treated mice (NK+LDCs). Cytokine analysis of the local tissues of the former compared with the latter exhibited lower levels of Th1 (IFN-γ) and Th17 (IL-17), but higher levels of Th2 (IL-4), cytokines. Consistently, NK-LDCs were less efficient in directing C. muridarum-specific Th1 and Th17 responses than NK+LDCs when cocultured with CD4(+) T cells. In NK cell/LDC coculture experiments, the blockade of NKG2D receptor reduced the production of IL-12p70, IL-6, and IL-23 by LDCs. The neutralization of IFN-γ in the culture decreased the production of IL-12p70 by LDCs, whereas the blockade of TNF-α resulted in diminished IL-6 production. Our findings demonstrate that NK cells modulate LDC function to elicit Th1/Th17 immunity during intracellular bacterial infection.

  8. Targeted antigen delivery to dendritic cells elicits robust antiviral T cell-mediated immunity in the liver

    PubMed Central

    Volckmar, Julia; Gereke, Marcus; Ebensen, Thomas; Riese, Peggy; Philipsen, Lars; Lienenklaus, Stefan; Wohlleber, Dirk; Klopfleisch, Robert; Stegemann-Koniszewski, Sabine; Müller, Andreas J.; Gruber, Achim D.; Knolle, Percy; Guzman, Carlos A.; Bruder, Dunja

    2017-01-01

    Hepatotropic viruses such as hepatitis C virus cause life-threatening chronic liver infections in millions of people worldwide. Targeted in vivo antigen-delivery to cross-presenting dendritic cells (DCs) has proven to be extraordinarily efficient in stimulating antigen-specific T cell responses. To determine whether this approach would as well be suitable to induce local antiviral effector T cells in the liver we compared different vaccine formulations based on either the targeting of DEC-205 or TLR2/6 on cross-presenting DCs or formulations not involving in vivo DC targeting. As read-outs we used in vivo hepatotropic adenovirus challenge, histology and automated multidimensional fluorescence microscopy (MELC). We show that targeted in vivo antigen delivery to cross-presenting DCs is highly effective in inducing antiviral CTLs capable of eliminating virus-infected hepatocytes, while control vaccine formulation not involving DC targeting failed to induce immunity against hepatotropic virus. Moreover, we observed distinct patterns of CD8+ T cell interaction with virus-infected and apoptotic hepatocytes in the two DC-targeting groups suggesting that the different vaccine formulations may stimulate distinct types of effector functions. Our findings represent an important step toward the future development of vaccines against hepatotropic viruses and the treatment of patients with hepatic virus infection after liver transplantation to avoid reinfection. PMID:28266658

  9. C-type lectin Mermaid inhibits dendritic cell mediated HIV-1 transmission to CD4+ T cells.

    PubMed

    Nabatov, Alexey A; de Jong, Marein A W P; de Witte, Lot; Bulgheresi, Silvia; Geijtenbeek, Teunis B H

    2008-09-01

    Dendritic cells (DCs) are important in HIV-1 transmission; DCs capture invading HIV-1 through the interaction of the gp120 oligosaccharides with the C-type lectin DC-SIGN and migrate to the lymphoid tissues where HIV-1 is transmitted to T cells. Thus, the HIV-1 envelope glycoprotein gp120 is an attractive target to prevent interactions with DCs and subsequent viral transmission. Here, we have investigated whether the structural homologue of DC-SIGN, the nematode C-type lectin Mermaid can be used to prevent HIV-1 transmission by DCs. Our data demonstrate that Mermaid interacts with high mannose structures present on HIV-1 gp120 and thereby inhibits HIV-1 binding to DC-SIGN on DCs. Moreover, Mermaid inhibits DC-SIGN-mediated HIV-1 transmission from DC to T cells. We have identified Mermaid as a non-cytotoxic agent that shares the glycan specificity with DC-SIGN and inhibits DC-SIGN-gp120 interaction. The results are important for the anti-HIV-1 microbicide development directed at preventing DC-HIV-1 interactions.

  10. Computational implications of cooperative plasticity induction at nearby dendritic sites.

    PubMed

    Morita, Kenji

    2009-01-06

    Recent studies have revealed that plasticity is not regulated independently at individual synapses but rather that there is cooperativity or associativity between nearby synapses in the dendritic tree of individual cortical pyramidal cells. Here, I summarize experimental results regarding such cooperative plasticity and its underlying mechanisms and consider their computational implications.

  11. Lymphopenia associated with highly virulent H5N1 virus infection due to plasmacytoid dendritic cell mediated apoptosis of T cells

    PubMed Central

    Boonnak, Kobporn; Vogel, Leatrice; Feldmann, Friederike; Feldmann, Heinz; Legge, Kevin L.; Subbarao, Kanta

    2014-01-01

    Although lymphopenia is a hallmark of severe infection with highly pathogenic H5N1 and the newly emerged H7N9 influenza viruses in humans, the mechanism(s) by which lethal H5N1 viruses cause lymphopenia in mammalian hosts remains poorly understood. Because influenza-specific T cell responses are initiated in the lung draining lymph nodes, and lymphocytes subsequently traffic to the lungs or peripheral circulation, we compared the immune responses in the lung draining lymph nodes following infection with a lethal A/HK/483/97 or non-lethal A/HK/486/97 (H5N1) virus in a mouse model. We found that lethal H5N1, but not non-lethal H5N1 virus infection in mice enhances Fas ligand (FasL) expression on plasmacytoid dendritic cells (pDCs), resulting in apoptosis of influenza-specific CD8+ T cells via a Fas-FasL mediated pathway. We also found that pDCs, but not other DC subsets, preferentially accumulate in the lung draining lymph nodes of lethal H5N1 virus-infected mice and that the induction of FasL expression on pDCs correlates with high levels of IL-12p40 monomer/homodimer in the lung draining lymph nodes. Our data suggest that one of the mechanisms of lymphopenia associated with lethal H5N1 virus infection involves a deleterious role for pDCs. PMID:24829418

  12. TLR3 or TLR4 Activation Enhances Mesenchymal Stromal Cell-Mediated Treg Induction via Notch Signaling.

    PubMed

    Rashedi, Iran; Gómez-Aristizábal, Alejandro; Wang, Xing-Hua; Viswanathan, Sowmya; Keating, Armand

    2017-01-01

    Mesenchymal stromal cells (MSCs) are the subject of numerous clinical trials, largely due to their immunomodulatory and tissue regenerative properties. Toll-like receptors (TLRs), especially TLR3 and TLR4, are highly expressed on MSCs and their activation can significantly modulate the immunosuppressive and anti-inflammatory functions of MSCs. While MSCs can recruit and promote the generation of regulatory T cells (Tregs), the effect of TLR activation on MSC-mediated Treg induction is unknown. In this study, we investigated the effect of ligand-mediated activation of TLR3 and TLR4 on Treg induction by human MSCs. We found that generation of Tregs in human CD4(+) lymphocyte and MSC cocultures was enhanced by either TLR3 or TLR4 activation of MSCs and that the increase was abolished by TLR3 and TLR4 gene-silencing. Augmented Treg induction by TLR-activated MSCs was cell contact-dependent and associated with increased gene expression of the Notch ligand, Delta-like 1. Moreover, inhibition of Notch signaling abrogated the augmented Treg levels in the MSC cocultures. Our data show that TLR3 or TLR4 activation of MSCs increases Treg induction via the Notch pathway and suggest new means to enhance the potency of MSCs for treating disorders with an underlying immune dysfunction, including steroid resistant acute graft-versus-host disease. Stem Cells 2017;35:265-275.

  13. Involvement of peritoneal dendritic cells in the induction of autoimmune prostatitis.

    PubMed

    Correa, S G; Riera, C M; Iribarren, P

    1997-04-01

    We have been working within a model of autoimmune prostatitis induced by the intraperitoneal administration of saline extract of rat male accessory glands (RAG) associated to liposomes. The intraperitoneal administration of RAG-liposomes elicits both primary and secondary cellular autoimmune responses to RAG as well as organ-specific lesions. To evaluate the participation of dendritic cells (DC) in the induction of the autoimmune response, we purified peritoneal DC (PDC) after a single injection of RAG-liposomes and we characterized this population by morphology and phenotype. Based on adherence and morphologic criteria, we determined that PDC comprised approximately 1% of the total peritoneal cells. The ultrastructure of the dendritic cell enriched fraction was assessed by electron microscopy. By FACS analysis, PDC showed a two to three-fold increase in expression of the IA molecule compared to macrophages. They expressed low but positive levels of the CD14 marker, and intermediate levels of both CD11b (Mac-1) and CD54 (ICAM-1) adhesion molecules. In addition, PDC transferred either intravenously or intraperitoneally efficiently elicited the autoimmune response to RAG in normal receptors. These results support the involvement of peritoneal dendritic cells in the induction of autoimmune prostatitis, modifying the idea of macrophages as the single antigen presenting cell in the peritoneal cavity.

  14. ONCOGENIC BRAF(V600E) PROMOTES STROMAL CELL-MEDIATED IMMUNOSUPPRESSION VIA INDUCTION OF INTERLEUKIN-1 IN MELANOMA

    PubMed Central

    Khalili, Jahan S.; Liu, Shujuan; Rodríguez-Cruz, Tania G.; Whittington, Mayra; Wardell, Seth; Liu, Chengwen; Zhang, Minying; Cooper, Zachary A.; Frederick, Dennie T.; Li, Yufeng; Zhang, Min; Joseph, Richard W.; Bernatchez, Chantale; Ekmekcioglu, Suhendan; Grimm, Elizabeth; Radvanyi, Laszlo G.; Davis, Richard E.; Davies, Michael A.; Wargo, Jennifer A.; Hwu, Patrick; Lizée, Gregory

    2012-01-01

    Purpose In this study, we assessed the specific role of BRAF(V600E) signaling in modulating the expression of immune regulatory genes in melanoma, in addition to analyzing downstream induction of immune suppression by primary human melanoma tumor-associated fibroblasts (TAFs). Experimental Design Primary human melanocytes and melanoma cell lines were transduced to express WT or V600E forms of BRAF, followed by gene expression analysis. The BRAF(V600E) inhibitor vemurafenib was used to confirm targets in BRAF(V600E)-positive melanoma cell lines and in tumors from melanoma patients undergoing inhibitor treatment. TAF lines generated from melanoma patient biopsies were tested for their ability to inhibit the function of tumor antigen-specific T-cells, prior to and following treatment with BRAF(V600E)-upregulated immune modulators. Transcriptional analysis of treated TAFs was conducted to identify potential mediators of T-cell suppression. Results Expression of BRAF(V600E) induced transcription of IL-1α and IL-1β in melanocytes and melanoma cell lines. Furthermore, vemurafenib reduced the expression of IL-1 protein in melanoma cell lines and most notably in human tumor biopsies from 11 of 12 melanoma patients undergoing inhibitor treatment. Treatment of melanoma-patient-derived TAFs with IL-1α/β significantly enhanced their ability to suppress the proliferation and function of melanoma-specific cytotoxic T cells, and this inhibition was partially attributable to upregulation by IL-1 of COX-2 and the PD-1 ligands PD-L1 and PD-L2 in TAFs. Conclusions This study reveals a novel mechanism of immune suppression sensitive to BRAF(V600E) inhibition, and suggests that clinical blockade of IL-1 may benefit patients with BRAF wild-type tumors and potentially synergize with immunotherapeutic interventions. PMID:22850568

  15. Usage of Murine T-cell Hybridoma Cells as Responder Cells Reveals Interference of Helicobacter Pylori with Human Dendritic Cell-mediated Antigen Presentation

    PubMed Central

    Fehlings, Michael; Drobbe, Lea; Beigier-Bompadre, Macarena; Viveros, Pablo Renner; Moos, Verena; Schneider, Thomas; Meyer, Thomas F.; Aebischer, Toni; Ignatius, Ralf

    2016-01-01

    Direct effects of Helicobacter pylori (H. pylori) on human CD4+ T-cells hamper disentangling a possible bacterial-mediated interference with major histocompatibility complex class II (MHC-II)-dependent antigen presentation to these cells. To overcome this limitation, we employed a previously described assay, which enables assessing human antigen-processing cell function by using murine T-cell hybridoma cells restricted by human leukocyte antigen (HLA) alleles. HLA-DR1+ monocyte-derived dendritic cells were exposed to H. pylori and pulsed with the antigen 85B from Mycobacterium tuberculosis (M. tuberculosis). Interleukin-2 (IL-2) secretion by AG85Baa97-112-specific hybridoma cells was then evaluated as an integral reporter of cognate antigen presentation. This methodology enabled revealing of interference of H. pylori with the antigen-presenting capacity of human dendritic cells. PMID:27980859

  16. PI3Kγ Is Critical for Dendritic Cell-Mediated CD8+ T Cell Priming and Viral Clearance during Influenza Virus Infection

    PubMed Central

    Nobs, Samuel Philip; Schneider, Christoph; Heer, Alex Kaspar; Huotari, Jatta; Helenius, Ari; Kopf, Manfred

    2016-01-01

    Phosphoinositide-3-kinases have been shown to be involved in influenza virus pathogenesis. They are targeted directly by virus proteins and are essential for efficient viral replication in infected lung epithelial cells. However, to date the role of PI3K signaling in influenza infection in vivo has not been thoroughly addressed. Here we show that one of the PI3K subunits, p110γ, is in fact critically required for mediating the host’s antiviral response. PI3Kγ deficient animals exhibit a delayed viral clearance and increased morbidity during respiratory infection with influenza virus. We demonstrate that p110γ is required for the generation and maintenance of potent antiviral CD8+ T cell responses through the developmental regulation of pulmonary cross-presenting CD103+ dendritic cells under homeostatic and inflammatory conditions. The defect in lung dendritic cells leads to deficient CD8+ T cell priming, which is associated with higher viral titers and more severe disease course during the infection. We thus identify PI3Kγ as a novel key host protective factor in influenza virus infection and shed light on an unappreciated layer of complexity concerning the role of PI3K signaling in this context. PMID:27030971

  17. TLR5 mediates CD172α(+) intestinal lamina propria dendritic cell induction of Th17 cells.

    PubMed

    Liu, Han; Chen, Feidi; Wu, Wei; Cao, Anthony T; Xue, Xiaochang; Yao, Suxia; Evans-Marin, Heather L; Li, Yan-Qing; Cong, Yingzi

    2016-02-24

    Multiple mechanisms exist in regulation of host responses to massive challenges from microbiota to maintain immune homeostasis in the intestines. Among these is the enriched Th17 cells in the intestines, which regulates intestinal homeostasis through induction of antimicrobial peptides and secretory IgA among others. However, the means by which Th17 cells develop in response to microbiota is still not completely understood. Although both TLR5 and CD172α(+) lamina propria dendritic cells (LPDC) have been shown to promote Th17 cell development, it is still unclear whether TLR5 mediates the CD172α(+)LPDC induction of Th17 cells. By using a microbiota antigen-specific T cell reporter mouse system, we demonstrated that microbiota antigen-specific T cells developed into Th17 cells in the intestinal LP, but not in the spleen when transferred into TCRβxδ(-/-) mice. LPDCs expressed high levels of TLR5, and most CD172α(+)LPDCs also co-expressed TLR5. LPDCs produced high levels of IL-23, IL-6 and TGFβ when stimulated with commensal flagellin and promoted Th17 cell development when cultured with full-length CBir1 flagellin but not CBir1 peptide. Wild-type CD172α(+), but not CD172α(-), LPDCs induced Th17 cells, whereas TLR5-deficient LPDC did not induce Th17 cells. Our data thereby demonstrated that TLR5 mediates CD172α(+)LPDC induction of Th17 cells in the intestines.

  18. What are the molecules involved in regulatory T-cells induction by dendritic cells in cancer?

    PubMed

    Ramos, Rodrigo Nalio; de Moraes, Cristiano Jacob; Zelante, Bruna; Barbuto, José Alexandre M

    2013-01-01

    Dendritic cells (DCs) are essential for the maintenance of homeostasis in the organism, and they do that by modulating lymphocyte priming, expansion, and response patterns according to signals they receive from the environment. The induction of suppressive lymphocytes by DCs is essential to hinder the development of autoimmune diseases but can be reverted against homeostasis when in the context of neoplasia. In this setting, the induction of suppressive or regulatory T cells contributes to the establishment of a state of tolerance towards the tumor, allowing it to grow unchecked by an otherwise functional immune system. Besides affecting its local environment, tumor also has been described as potent sources of anti-inflammatory/suppressive factors, which may act systemically, generating defects in the differentiation and maturation of immune cells, far beyond the immediate vicinity of the tumor mass. Cytokines, as IL-10 and TGF-beta, as well as cell surface molecules like PD-L1 and ICOS seem to be significantly involved in the redirection of DCs towards tolerance induction, and recent data suggest that tumor cells may, indeed, modulate distinct DCs subpopulations through the involvement of these molecules. It is to be expected that the identification of such molecules should provide molecular targets for more effective immunotherapeutic approaches to cancer.

  19. Enhancement of dendritic cell-based vaccine potency by anti-apoptotic siRNAs targeting key pro-apoptotic proteins in cytotoxic CD8(+) T cell-mediated cell death.

    PubMed

    Kim, Jin Hee; Kang, Tae Heung; Noh, Kyung Hee; Bae, Hyun Cheol; Kim, Seok-Ho; Yoo, Young Do; Seong, Seung-Yong; Kim, Tae Woo

    2009-01-29

    Dendritic cells (DCs) have become an important measure for the treatment of malignancies. Current DC preparations, however, generate short-lived DCs because they are subject to cell death from various apoptotic pressures. Antigen-specific CD8(+) cytotoxic T lymphocytes (CTLs) is one of the main obstacles to limit the DC-mediated immune priming since CTLs can recognize the target antigen expressing DCs as target cells and kill the DCs. CTLs secret perforin and serine protease granzymes during CTL killing. Perforin and serine protease granzymes induce the release of a number of mitochondrial pro-apoptotic factors, which are controlled by members of the BCL-2 family, such as BAK, BAX and BIM. FasL linking to Fas on DCs triggers the activation of caspase-8, which eventually leads to mitochondria-mediated apoptosis via truncation of BID. In this study, we tried to enhance the DC priming capacity by prolonging DC survival using anti-apoptotic siRNA targeting these key pro-apoptotic molecules in CTL killing. Human papillomavirus (HPV)-16 E7 antigen presenting DCs that were transfected with these anti-apoptotic siRNAs showed increased resistance to T cell-mediated death, leading to enhanced E7-specific CD8(+) T cell activation in vitro and in vivo. Among them, siRNA targeting BIM (siBIM) generated strongest E7-specific E7-specific CD8(+) T cell immunity. More importantly, vaccination with E7 presenting DCs transfected with siBIM was capable of generating a marked therapeutic effect in vaccinated mice. Our data indicate that ex vivo manipulation of DCs with siBIM may represent a plausible strategy for enhancing dendritic cell-based vaccine potency.

  20. Induction of JAM-A during differentiation of human THP-1 dendritic cells.

    PubMed

    Ogasawara, Noriko; Kojima, Takashi; Go, Mitsuru; Fuchimoto, Jun; Kamekura, Ryuta; Koizumi, Jun-ichi; Ohkuni, Tsuyoshi; Masaki, Tomoyuki; Murata, Masaki; Tanaka, Satoshi; Ichimiya, Shingo; Himi, Tetsuo; Sawada, Norimasa

    2009-11-20

    Junctional adhesion molecule (JAM)-A is not only localized at tight junctions of endothelial and epithelial cells but is also expressed on circulating leukocytes and dendritic cells (DCs). In the present study, to investigate the regulation of JAM-A in DCs, mature DCs were differentiated from the human monocytic cell THP-1 by treatment with IL-4, GM-CSF, TNF-alpha, and ionomycin, and some cells were pretreated with the PPAR-gamma agonists. In the THP-1 monocytes, mRNAs of tight junction molecules, occludin, tricellulin, JAM-A, ZO-1, ZO-2 and claudin-4, -7, -8, and -9 were detected by RT-PCR. In mature DCs that had elongated dendrites, mRNA and protein of JAM-A were significantly increased compared to the monocytes. PPAR-gamma agonists prevented the elongation of dentrites but not upregulation of JAM-A in mature DCs. These findings indicated that the induction of JAM-A occurred during differentiation of human THP-1 DCs and was independent of PPAR-gamma and the p38 MAPK pathway.

  1. The Role of Dendritic Cell Maturation in the Induction of Insulin-Dependent Diabetes Mellitus

    PubMed Central

    Mbongue, Jacques C.; Nieves, Hector A.; Torrez, Timothy W.; Langridge, William H. R.

    2017-01-01

    Dendritic cells (DCs) are the dominant class of antigen-presenting cells in humans and are largely responsible for the initiation and guidance of innate and adaptive immune responses involved in maintenance of immunological homeostasis. Immature dendritic cells (iDCs) phagocytize pathogens and toxic proteins and in endosomal vesicles degrade them into small fragments for presentation on major histocompatibility complex (MHC) II receptor molecules to naïve cognate T cells (Th0). In addition to their role in stimulation of immunity, DCs are involved in the induction and maintenance of immune tolerance toward self-antigens. During activation, the iDCs become mature. Maturation begins when the DCs cease taking up antigens and begin to migrate from their location in peripheral tissues to adjacent lymph nodes or the spleen where during their continued maturation the DCs present stored antigens on surface MHCII receptor molecules to naive Th0 cells. During antigen presentation, the DCs upregulate the biosynthesis of costimulatory receptor molecules CD86, CD80, CD83, and CD40 on their plasma membrane. These activated DC receptor molecules bind cognate CD28 receptors presented on the Th0 cell membrane, which triggers DC secretion of IL-12 or IL-10 cytokines resulting in T cell differentiation into pro- or anti-inflammatory T cell subsets. Although basic concepts involved in the process of iDC activation and guidance of Th0 cell differentiation have been previously documented, they are poorly defined. In this review, we detail what is known about the process of DC maturation and its role in the induction of insulin-dependent diabetes mellitus autoimmunity.

  2. Regulatory T-Cell-Mediated Suppression of Conventional T-Cells and Dendritic Cells by Different cAMP Intracellular Pathways.

    PubMed

    Rueda, Cesar M; Jackson, Courtney M; Chougnet, Claire A

    2016-01-01

    Regulatory T-cells (Tregs) mediate their suppressive action by acting directly on conventional T-cells (Tcons) or dendritic cells (DCs). One mechanism of Treg suppression is the increase of cyclic adenosine 3',5'-monophosphate (cAMP) levels in target cells. Tregs utilize cAMP to control Tcon responses, such as proliferation and cytokine production. Tregs also exert their suppression on DCs, diminishing DC immunogenicity by downmodulating the expression of costimulatory molecules and actin polymerization at the immunological synapse. The Treg-mediated usage of cAMP occurs through two major mechanisms. The first involves the Treg-mediated influx of cAMP in target cells through gap junctions. The second is the conversion of adenosine triphosphate into adenosine by the ectonucleases CD39 and CD73 present on the surface of Tregs. Adenosine then binds to receptors on the surface of target cells, leading to increased intracellular cAMP levels in these targets. Downstream, cAMP can activate the canonical protein kinase A (PKA) pathway and the exchange protein activated by cyclic AMP (EPAC) non-canonical pathway. In this review, we discuss the most recent findings related to cAMP activation of PKA and EPAC, which are implicated in Treg homeostasis as well as the functional alterations induced by cAMP in cellular targets of Treg suppression.

  3. Insulin-like growth factors inhibit dendritic cell-mediated anti-tumor immunity through regulating ERK1/2 phosphorylation and p38 dephosphorylation.

    PubMed

    Huang, Ching-Ting; Chang, Ming-Cheng; Chen, Yu-Li; Chen, Tsung-Ching; Chen, Chi-An; Cheng, Wen-Fang

    2015-04-01

    Insulin-like growth factors (IGFs) can promote tumorigenesis via inhibiting the apoptosis of cancer cells. The relationship between IGFs and dendritic cell (DC)-mediated immunity were investigated. Advanced-stage ovarian carcinoma patients were first evaluated to show higher IGF-1 and IGF-2 concentrations in their ascites than early-stage patients. IGFs could suppress DCs' maturation, antigen presenting abilities, and the ability to activate antigen-specific CD8(+) T cell. IGF-treated DCs also secreted higher concentrations of IL-10 and TNF-α. IGF-treated DCs showed decreased ERK1/2 phosphorylation and reduced p38 dephosphorylation. The percentages of matured DCs in the ascites were significantly lower in the IGF-1 or IGF-2 highly-expressing WF-3 tumor-bearing mice. The IGF1R inhibitor - NVP-AEW541, could block the effects of IGFs to rescue DCs' maturation and to restore DC-mediated antigen-specific immunity through enhancing ERK1/2 phosphorylation and p38 dephosphorylation. IGFs can inhibit DC-mediated anti-tumor immunity through suppressing maturation and function and the IGF1R inhibitor could restore the DC-mediated anti-tumor immunity. Blockade of IGFs could be a potential strategy for cancer immunotherapy.

  4. Dendrite

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Researchers have found that as melted metals and alloys (combinations of metals) solidify, they can form with different arrangements of atoms, called microstructures. These microstructures depend on the shape of the interface (boundary) between the melted metal and the solid crystal it is forming. There are generally three shapes that the interface can take: planar, or flat; cellular, which looks like the cells of a beehive; and dendritic, which resembles tiny fir trees. Convection at this interface can affect the interface shape and hide the other phenomena (physical events). To reduce the effects of convection, researchers conduct experiments that examine and control conditions at the interface in microgravity. Microgravity also helps in the study of alloys composed of two metals that do not mix. On Earth, the liquid mixtures of these alloys settle into different layers due to gravity. In microgravity, the liquid metals do not settle, and a solid more uniform mixture of both metals can be formed.

  5. Dendritic cell-activated cytokine-induced killer cell-mediated immunotherapy is safe and effective for cancer patients >65 years old

    PubMed Central

    Liu, Yanfeng; Liu, Haibo; Liu, Hausheng; He, Pengcheng; Li, Jing; Liu, Xin; Chen, Limei; Wang, Mengchang; Xi, Jiejing; Wang, Huaiyu; Zhang, Haitao; Zhu, Ying; Zhu, Wei; Ning, Jing; Guo, Caili; Sun, Chunhong; Zhang, Mei

    2016-01-01

    Individuals >65 years old account for a large proportion of cancer patients, and usually have poor prognoses due to relative weaker physiological function and lower drug tolerance. To characterize the efficacy and safety of dendritic cell (DC)-activated cytokine-induced killer cell (CIK)-mediated treatment, and develop an adoptive immunotherapy for cancer patients >65 years old, a retrospective study was performed in 58 cancer sufferers who received 1–4 cycles of DC-activated CIK (DC-CIK) treatment and evaluated the response (tumor remission rate) and toxicity (side effects to the treatment). The present results showed that DCs and CIKs could be expanded rapidly in vitro, and following co-culture with DCs, the population of cluster of differentiation (CD) 3+, CD3+CD4+, CD3+CD8+ and CD3+CD56+ CIKs was significantly increased compared to CIKs without DC activation (P=0.044). In addition, DC-CIK infusion produced marked clinical outcomes, resulting in an objective remission rate, overall clinical benefit rate and Karnofsky performance status of 44.83, 75.86 and 87.28±5.46%, respectively, which was significantly improved compared with prior to treatment (P<0.05). Additionally, subsequent to two cycles of this immunotherapy, several tumor marker expression levels declined, returning to the normal range. The proportion of CD3+CD4+ (P=0.017) and CD3+CD8+ (P=0.023) lymphocytes, and the population of CD4/CD8 cells (P=0.024) were also increased. In conclusion, the present study suggests that the immunotherapy mediated by DC-CIK is safe and effective for cancer patients aged >65 years. PMID:28105230

  6. Dendritic cell-mediated, DNA-based vaccination against hepatitis C induces the multi-epitope-specific response of humanized, HLA transgenic mice.

    PubMed

    Mishra, Sasmita; Lavelle, Bianca J; Desrosiers, Joe; Ardito, Matt T; Terry, Frances; Martin, William D; De Groot, Anne S; Gregory, Stephen H

    2014-01-01

    Hepatitis C virus (HCV) is the etiologic agent of chronic liver disease, hepatitis C. Spontaneous resolution of viral infection is associated with vigorous HLA class I- and class II-restricted T cell responses to multiple viral epitopes. Unfortunately, only 20% of patients clear infection spontaneously, most develop chronic disease and require therapy. The response to chemotherapy varies, however; therapeutic vaccination offers an additional treatment strategy. To date, therapeutic vaccines have demonstrated only limited success. Vector-mediated vaccination with multi-epitope-expressing DNA constructs alone or in combination with chemotherapy offers an additional treatment approach. Gene sequences encoding validated HLA-A2- and HLA-DRB1-restricted epitopes were synthesized and cloned into an expression vector. Dendritic cells (DCs) derived from humanized, HLA-A2/DRB1 transgenic (donor) mice were transfected with these multi-epitope-expressing DNA constructs. Recipient HLA-A2/DRB1 mice were vaccinated s.c. with transfected DCs; control mice received non-transfected DCs. Peptide-specific IFN-γ production by splenic T cells obtained at 5 weeks post-immunization was quantified by ELISpot assay; additionally, the production of IL-4, IL-10 and TNF-α were quantified by cytokine bead array. Splenocytes derived from vaccinated HLA-A2/DRB1 transgenic mice exhibited peptide-specific cytokine production to the vast majority of the vaccine-encoded HLA class I- and class II-restricted T cell epitopes. A multi-epitope-based HCV vaccine that targets DCs offers an effective approach to inducing a broad immune response and viral clearance in chronic, HCV-infected patients.

  7. Helper role of NK cells during the induction of anticancer responses by dendritic cells.

    PubMed

    Kalinski, Pawel; Giermasz, Adam; Nakamura, Yutaro; Basse, Per; Storkus, Walter J; Kirkwood, John M; Mailliard, Robbie B

    2005-02-01

    Recent reports demonstrate that natural killer (NK) cells and dendritic cells (DC) support each other's activity in a positive feedback. We observed that activated NK cells induce the maturation of DCs into stable type-1 polarized DCs (DC1), characterized by up to 100-fold enhanced ability to produce IL-12p70 in response to subsequent interaction with Th cells. DC1 induction depends on NK cell-produced IFN-gamma and TNF-alpha, with a possible involvement of additional factors. DC1, induced by NK cells or by NK cell-related soluble factors, are stable, resistant to tumor-related suppressive factors, and show strongly enhanced ability to induce Th1 and CTL responses. In analogy to resting T cells, the induction of "helper" function of NK cells relies on a two-signal activation paradigm. While NKG2D-dependent tumor cell recognition is sufficient to induce the cytotoxic "effector" function of NK cells, the induction of "NK cell help" requires additional signals from type-1 IFNs, products of virally-infected cells, or from IL-2. Compared to non-polarized DCs currently-used in clinical trials, DC1s act as superior inducers of anti-cancer CTL responses during in vitro sensitization. The current data provides rationale for the clinical use of DC1s in cancer and chronic infections (such as HIV), as a new generation DC-based vaccines, uniquely combining fully mature DC status with an elevated, rather than "exhausted" ability to produce bioactive IL-12p70. We are currently implementing stage I/II clinical trials, testing the effectiveness of DC1s induced by NK cells or by NK cell-related factors, as therapeutic vaccines against melanoma.

  8. Induction of Wnt-inducible signaling protein-1 correlates with invasive breast cancer oncogenesis and reduced type 1 cell-mediated cytotoxic immunity: a retrospective study.

    PubMed

    Klinke, David J

    2014-01-01

    Innate and type 1 cell-mediated cytotoxic immunity function as important extracellular control mechanisms that maintain cellular homeostasis. Interleukin-12 (IL12) is an important cytokine that links innate immunity with type 1 cell-mediated cytotoxic immunity. We recently observed in vitro that tumor-derived Wnt-inducible signaling protein-1 (WISP1) exerts paracrine action to suppress IL12 signaling. The objective of this retrospective study was three fold: 1) to determine whether a gene signature associated with type 1 cell-mediated cytotoxic immunity was correlated with overall survival, 2) to determine whether WISP1 expression is increased in invasive breast cancer, and 3) to determine whether a gene signature consistent with inhibition of IL12 signaling correlates with WISP1 expression. Clinical information and mRNA expression for genes associated with anti-tumor immunity were obtained from the invasive breast cancer arm of the Cancer Genome Atlas study. Patient cohorts were identified using hierarchical clustering. The immune signatures associated with the patient cohorts were interpreted using model-based inference of immune polarization. Reverse phase protein array, tissue microarray, and quantitative flow cytometry in breast cancer cell lines were used to validate observed differences in gene expression. We found that type 1 cell-mediated cytotoxic immunity was correlated with increased survival in patients with invasive breast cancer, especially in patients with invasive triple negative breast cancer. Oncogenic transformation in invasive breast cancer was associated with an increase in WISP1. The gene expression signature in invasive breast cancer was consistent with WISP1 as a paracrine inhibitor of type 1 cell-mediated immunity through inhibiting IL12 signaling and promoting type 2 immunity. Moreover, model-based inference helped identify appropriate immune signatures that can be used as design constraints in genetically engineering better pre

  9. Tussilagone inhibits dendritic cell functions via induction of heme oxygenase-1.

    PubMed

    Park, Yunsoo; Ryu, Hwa Sun; Lee, Hong Kyung; Kim, Ji Sung; Yun, Jieun; Kang, Jong Soon; Hwang, Bang Yeon; Hong, Jin Tae; Kim, Youngsoo; Han, Sang-Bae

    2014-10-01

    Sesquiterpenoid tussilagone (TUS) has a variety of pharmacological activities, such as anti-oxidant, anti-cancer, and anti-inflammatory activities. In this study, we investigated the effects of TUS on dendritic cell (DC) functions and the underlying mechanisms. TUS inhibited lipopolysaccharide (LPS)-induced activation of DCs, as shown by decrease in surface molecule expression, cytokine production, cell migration, and allo-T cell activation. In addition, TUS inhibited LPS-induced activation of NF-κB, MAPKs, and IRF-3 signalings in DCs, although it did not directly affect kinase activities of IRAK1/4, TAK1, and IKK, which suggests that TUS might indirectly inhibit TLR signaling in DCs. As a critical mechanism, we showed that TUS activated heme oxygenase-1 (HO-1), which degrades heme to immunosuppressive products, such as carbon monoxide and bilirubin. HO-1 inhibitor reversed the inhibitory activity of TUS in DCs. In conclusion, this study suggests that TUS inhibits DC function through the induction of HO-1.

  10. Susceptibility to natural killer cell-mediated lysis of colon cancer cells is enhanced by treatment with epidermal growth factor receptor inhibitors through UL16-binding protein-1 induction.

    PubMed

    Bae, Jae-Ho; Kim, So-Jung; Kim, Mi-Ju; Oh, Sae-Ock; Chung, Joo-Seop; Kim, Sun-Hee; Kang, Chi-Dug

    2012-01-01

    We have previously shown that inhibition of intracellular signaling pathways by treatment with quercetin induced the expression of natural killer cell group 2D (NKG2D) ligands on cancer cells and made the cells sensitive to natural killer (NK)-cell mediated cytotoxicity. In the present study, we investigated whether epidermal growth factor receptor (EGFR) inhibitors could induce the expression of NKG2D ligands in colon cancer cells. Treatment with EGFR inhibitors predominantly increased the levels of mRNA transcripts and surface protein of UL16-binding protein-1 (ULBP1) in various colon cancer cells, including KM12, Caco-2, HCT-15, and HT-29, which express EGFR, and increased susceptibility of these colon cancer cells to NK-92 cells. The expression of ULBP1 was not induced by inhibitors of nuclear factor-κB, phosphatidylinositol 3 kinase, and MAPK, but was induced by inhibitors of PKC, and the induction of ULBP1 expression with EGFR inhibitors was prevented by treatment with PMA in colon cancer cells. A transcription factor, activator protein-2 alpha (AP-2α), which has a suppressive effect on ULBP1 transcription, was prevented from binding to the ULBP1 promoter by treatment with EGFR inhibitors. The present study suggests that EGFR inhibitors can enhance the susceptibility to NK cell-mediated lysis of colon cancer cells by induction of ULBP1 via inhibition of the PKC pathway.

  11. Cell-Mediated Drugs Delivery

    PubMed Central

    Batrakova, Elena V.; Gendelman, Howard E.; Kabanov, Alexander V.

    2011-01-01

    INTRODUCTION Drug targeting to sites of tissue injury, tumor or infection with limited toxicity is the goal for successful pharmaceutics. Immunocytes (including mononuclear phagocytes (dendritic cells, monocytes and macrophages), neutrophils, and lymphocytes) are highly mobile; they can migrate across impermeable barriers and release their drug cargo at sites of infection or tissue injury. Thus immune cells can be exploited as trojan horses for drug delivery. AREAS COVERED IN THIS REVIEW This paper reviews how immunocytes laden with drugs can cross the blood brain or blood tumor barriers, to facilitate treatments for infectious diseases, injury, cancer, or inflammatory diseases. The promises and perils of cell-mediated drug delivery are reviewed, with examples of how immunocytes can be harnessed to improve therapeutic end points. EXPERT OPINION Using cells as delivery vehicles enables targeted drug transport, and prolonged circulation times, along with reductions in cell and tissue toxicities. Such systems for drug carriage and targeted release represent a novel disease combating strategy being applied to a spectrum of human disorders. The design of nanocarriers for cell-mediated drug delivery may differ from those used for conventional drug delivery systems; nevertheless, engaging different defense mechanisms into drug delivery may open new perspectives for the active delivery of drugs. PMID:21348773

  12. Gene induction during differentiation of human monocytes into dendritic cells: an integrated study at the RNA and protein levels

    PubMed Central

    Angénieux, Catherine; Fricker, Dominique; Strub, Jean-Marc; Luche, Sylvie; Bausinger, Huguette; Cazenave, Jean-Pierre; Van Dorsselaer, Alain; Hanau, Daniel; de la Salle, Henri; Rabilloud, Thierry

    2001-01-01

    Changes in gene expression occurring during differentiation of human monoytes into dendritic cells were studied at the RNA and protein levels. These studies showed the induction of several gene classes corresponding to various biological functions. These functions encompass of course antigen processing and presentation, cytoskeleton, cell signalling and signal transduction, but also an increase of mitochondrial function and of the protein synthesis machinery, including some, but not all, chaperones. These changes put in perspective the events occurring during this differentiation process. On a more technical point, it appears that the studies carried out at the RNA and protein levels are highly complementary. PMID:11793251

  13. Classical dendritic cells are required for dietary antigen-mediated peripheral regulatory T cell and tolerance induction

    PubMed Central

    Esterházy, Daria; Loschko, Jakob; London, Mariya; Jove, Veronica; Oliveira, Thiago Y.; Mucida, Daniel

    2016-01-01

    Oral tolerance prevents pathological inflammatory responses towards innocuous foreign antigens via peripheral regulatory T cells (pTreg cells). However, whether a particular subset of antigen-presenting cells (APCs) is required during dietary antigen exposure to instruct naïve CD4+ T cells to differentiate into pTreg cells has not been defined. Using myeloid lineage-specific APC depletion in mice, we found that monocyte-derived APCs are dispensable, while classical dendritic cells (cDCs) are critical for pTreg cell induction and oral tolerance. CD11b− cDCs from the gut-draining lymph nodes efficiently induced pTreg cells, and conversely, loss of IRF8-dependent CD11b− cDCs impaired their polarization, although oral tolerance remained intact. These data reveal the hierarchy of cDC subsets in pTreg cell induction and their redundancy during oral tolerance development. PMID:27019226

  14. Characterization of dermal dendritic cells in psoriasis. Autostimulation of T lymphocytes and induction of Th1 type cytokines.

    PubMed Central

    Nestle, F O; Turka, L A; Nickoloff, B J

    1994-01-01

    Local activation of T lymphocytes is regarded as an important immunological component of psoriatic skin lesions. Within psoriatic plaques (PP) there are large numbers of dermal dendritic cells (DDCs) immediately beneath the hyperplastic epidermis surrounded by T cells. In this study we investigated the ability of DDCs isolated from PP skin to support immune responses to resting peripheral blood T cells. For comparison, other dendritic cells were obtained from blood of the same psoriatic patients, as well as DDCs from skin of normal healthy individuals (designated NN skin). All dendritic cells studied had high surface expression of HLA-DR, B7, and lymphocyte function associated antigen-1 molecules. T cell proliferative responses and cytokine production profiles to these various dendritic cells were measured in the absence and presence of PHA or bacterial-derived superantigens. In the absence of exogenous mitogens, PP skin-derived DDCs were much more effective stimulators of spontaneous T cell proliferation compared with either psoriatic blood-derived or NN skin-derived dendritic cells. Antibody blocking studies revealed involvement of HLA-DR, B7, and lymphocyte function associated antigen-1 on PP skin-derived DDCs. Cytokine profiles revealed that in the absence of exogenous stimuli PP skin-derived DDCs mediated a T cell response with high levels of IL-2 and IFN-gamma, but not IL-4 or IL-10. NN skin-derived DDCs produced a similar qualitative response, but quantitative amounts of all cytokines measured were lower. Upon addition of PHA or superantigens, both PP skin-derived and NN skin-derived DDCs mediated high levels of IL-2 and IFN-gamma production, with induction of IL-4 particularly evident for PHA reactions. Addition of conditioned medium from psoriatic dermal fragments did not enhance the autostimulatory capacity of blood-derived dendritic cells. These findings highlight the potent autostimulatory potential of PP skin-derived DDCs and suggest an important

  15. CD45R, CD44 and MHC class II are signaling molecules for the cytoskeleton-dependent induction of dendrites and motility in activated B cells.

    PubMed

    Partida-Sánchez, S; Garibay-Escobar, A; Frixione, E; Parkhouse, R M; Santos-Argumedo, L

    2000-09-01

    Anti-CD44 or anti-MHC II antibodies bound to tissue culture plates have previously been shown to induce a dramatic generation of dendritic processes in activated murine B cells. In this study, we demonstrate a similar generation of dendrites and cell motility in activated B cells through CD45R. The dynamic formation of dendritic processes and associated induction of cell motility were analyzed by video microscopy and were characterized by a rapid, and multidirectional emission of dendrites with retractile behavior. The addition of cytochalasin E totally blocked dendrites formation and motility induced through either CD45R, CD44 or MHC II, suggesting that the necessary cytoskeletal rearrangements require active polymerization of actin. Confocal microscopy showed an accumulation of F-actin in the dendrites, as long as cells were elongating. In contrast, G-actin was localized in the perinuclear area and also accumulated in sites where dendrites originated. Preincubation of B cells with staurosporine (a PKC inhibitor) or BAPTA-AM (a calcium chelator) prevented these morphological changes, indicating additionally a requirement for a PKC-calcium-dependent activity. Dendrite formation and cellular motility, therefore, seem to be two manifestations of the same phenomenon, and CD44, CD45R and MHC II appear to be signaling molecules for the observed cytoskeleton-dependent morphological changes.

  16. Exploring the induction of preproinsulin-specific Foxp3(+) CD4(+) Treg cells that inhibit CD8(+) T cell-mediated autoimmune diabetes by DNA vaccination.

    PubMed

    Stifter, Katja; Schuster, Cornelia; Schlosser, Michael; Boehm, Bernhard Otto; Schirmbeck, Reinhold

    2016-07-11

    DNA vaccination is a promising strategy to induce effector T cells but also regulatory Foxp3(+) CD25(+) CD4(+) Treg cells and inhibit autoimmune disorders such as type 1 diabetes. Little is known about the antigen requirements that facilitate priming of Treg cells but not autoreactive effector CD8(+) T cells. We have shown that the injection of preproinsulin (ppins)-expressing pCI/ppins vector into PD-1- or PD-L1-deficient mice induced K(b)/A12-21-monospecific CD8(+) T cells and autoimmune diabetes. A pCI/ppinsΔA12-21 vector (lacking the critical K(b)/A12-21 epitope) did not induce autoimmune diabetes but elicited a systemic Foxp3(+) CD25(+) Treg cell immunity that suppressed diabetes induction by a subsequent injection of the diabetogenic pCI/ppins. TGF-β expression was significantly enhanced in the Foxp3(+) CD25(+) Treg cell population of vaccinated/ppins-primed mice. Ablation of Treg cells in vaccinated/ppins-primed mice by anti-CD25 antibody treatment abolished the protective effect of the vaccine and enabled diabetes induction by pCI/ppins. Adoptive transfer of Treg cells from vaccinated/ppins-primed mice into PD-L1(-/-) hosts efficiently suppressed diabetes induction by pCI/ppins. We narrowed down the Treg-stimulating domain to a 15-residue ppins76-90 peptide. Vaccine-induced Treg cells thus play a crucial role in the control of de novo primed autoreactive effector CD8(+) T cells in this diabetes model.

  17. Exploring the induction of preproinsulin-specific Foxp3+ CD4+ Treg cells that inhibit CD8+ T cell-mediated autoimmune diabetes by DNA vaccination

    PubMed Central

    Stifter, Katja; Schuster, Cornelia; Schlosser, Michael; Boehm, Bernhard Otto; Schirmbeck, Reinhold

    2016-01-01

    DNA vaccination is a promising strategy to induce effector T cells but also regulatory Foxp3+ CD25+ CD4+ Treg cells and inhibit autoimmune disorders such as type 1 diabetes. Little is known about the antigen requirements that facilitate priming of Treg cells but not autoreactive effector CD8+ T cells. We have shown that the injection of preproinsulin (ppins)-expressing pCI/ppins vector into PD-1- or PD-L1-deficient mice induced Kb/A12-21-monospecific CD8+ T cells and autoimmune diabetes. A pCI/ppinsΔA12-21 vector (lacking the critical Kb/A12-21 epitope) did not induce autoimmune diabetes but elicited a systemic Foxp3+ CD25+ Treg cell immunity that suppressed diabetes induction by a subsequent injection of the diabetogenic pCI/ppins. TGF-β expression was significantly enhanced in the Foxp3+ CD25+ Treg cell population of vaccinated/ppins-primed mice. Ablation of Treg cells in vaccinated/ppins-primed mice by anti-CD25 antibody treatment abolished the protective effect of the vaccine and enabled diabetes induction by pCI/ppins. Adoptive transfer of Treg cells from vaccinated/ppins-primed mice into PD-L1−/− hosts efficiently suppressed diabetes induction by pCI/ppins. We narrowed down the Treg-stimulating domain to a 15-residue ppins76–90 peptide. Vaccine-induced Treg cells thus play a crucial role in the control of de novo primed autoreactive effector CD8+ T cells in this diabetes model. PMID:27406624

  18. Deletion of Kv4.2 gene eliminates dendritic A-type K+ current and enhances induction of long-term potentiation in hippocampal CA1 pyramidal neurons.

    PubMed

    Chen, Xixi; Yuan, Li-Lian; Zhao, Cuiping; Birnbaum, Shari G; Frick, Andreas; Jung, Wonil E; Schwarz, Thomas L; Sweatt, J David; Johnston, Daniel

    2006-11-22

    Dendritic, backpropagating action potentials (bAPs) facilitate the induction of Hebbian long-term potentiation (LTP). Although bAPs in distal dendrites of hippocampal CA1 pyramidal neurons are attenuated when propagating from the soma, their amplitude can be increased greatly via downregulation of dendritic A-type K+ currents. The channels that underlie these currents thus may represent a key regulatory component of the signaling pathways that lead to synaptic plasticity. We directly tested this hypothesis by using Kv4.2 knock-out mice. Deletion of the Kv4.2 gene and a loss of Kv4.2 protein resulted in a specific and near-complete elimination of A-type K+ currents from the apical dendrites of CA1 pyramidal neurons. The absence of dendritic Kv4.2-encoded A-type K+ currents led to an increase of bAP amplitude and an increase of concurrent Ca2+ influx. Furthermore, CA1 pyramidal neurons lacking dendritic A-type K+ currents from Kv4.2 knock-out mice exhibited a lower threshold than those of wild-type littermates for LTP induction with the use of a theta burst pairing protocol. LTP triggered with the use of a saturating protocol, on the other hand, remained indistinguishable between Kv4.2 knock-out and wild-type neurons. Our results support the hypothesis that dendritic A-type K+ channels, composed of Kv4.2 subunits, regulate action potential backpropagation and the induction of specific forms of synaptic plasticity.

  19. Induction of Indoleamine 2, 3-Dioxygenase in Human Dendritic Cells by a Cholera Toxin B Subunit—Proinsulin Vaccine

    PubMed Central

    Mbongue, Jacques C.; Nicholas, Dequina A.; Zhang, Kangling; Kim, Nan-Sun; Hamilton, Brittany N.; Larios, Marco; Zhang, Guangyu; Umezawa, Kazuo; Firek, Anthony F.; Langridge, William H. R.

    2015-01-01

    Dendritic cells (DC) interact with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this study, immature human dendritic cells (iDC) were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS). Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1). Increased biosynthesis of the immunosuppressive enzyme was detected in DCs inoculated with the CTB-INS fusion protein but not in DCs inoculated with proinsulin, CTB, or an unlinked combination of the two proteins. Immunoblot and PCR analyses of vaccine treated DCs detected IDO1mRNA by 3 hours and IDO1 protein synthesis by 6 hours after vaccine inoculation. Determination of IDO1 activity in vaccinated DCs by measurement of tryptophan degradation products (kynurenines) showed increased tryptophan cleavage into N-formyl kynurenine. Vaccination did not interfere with monocytes differentiation into DC, suggesting the vaccine can function safely in the human immune system. Treatment of vaccinated DCs with pharmacological NF-κB inhibitors ACHP or DHMEQ significantly inhibited IDO1 biosynthesis, suggesting a role for NF-κB signaling in vaccine up-regulation of dendritic cell IDO1. Heat map analysis of the proteomic data revealed an overall down-regulation of vaccinated DC functions, suggesting vaccine suppression of DC maturation. Together, our experimental data indicate that CTB-INS vaccine induction of IDO1 biosynthesis in human DCs may result in the inhibition of DC maturation generating a durable state of immunological tolerance. Understanding how CTB-INS modulates IDO1 activity in human DCs will facilitate vaccine efficacy and safety, moving this immunosuppressive strategy closer to clinical applications for prevention of type 1

  20. Selective induction of cell-mediated immunity and protection of rhesus macaques from chronic SHIV{sub KU2} infection by prophylactic vaccination with a conserved HIV-1 envelope peptide-cocktail

    SciTech Connect

    Nehete, Pramod N.; Nehete, Bharti P.; Hill, Lori; Manuri, Pallavi R.; Baladandayuthapani, Veerabhadran; Feng Lei; Simmons, Johnny; Sastry, K. Jagannadha

    2008-01-05

    Infection of Indian-origin rhesus macaques by the simian human immunodeficiency virus (SHIV) is considered to be a suitable preclinical model for directly testing efficacy of vaccine candidates based on the HIV-1 envelope. We used this model for prophylactic vaccination with a peptide-cocktail comprised of highly conserved HIV-1 envelope sequences immunogenic/antigenic in macaques and humans. Separate groups of macaques were immunized with the peptide-cocktail by intravenous and subcutaneous routes using autologous dendritic cells (DC) and Freund's adjuvant, respectively. The vaccine elicited antigen specific IFN-{gamma}-producing cells and T-cell proliferation, but not HIV-neutralizing antibodies. The vaccinated animals also exhibited efficient cross-clade cytolytic activity against target cells expressing envelope proteins corresponding to HIV-1 strains representative of multiple clades that increased after intravenous challenge with pathogenic SHIV{sub KU2}. Virus-neutralizing antibodies were either undetectable or present only transiently at low levels in the control as well as vaccinated monkeys after infection. Significant control of plasma viremia leading to undetectable levels was achieved in majority of vaccinated monkeys compared to mock-vaccinated controls. Monkeys vaccinated with the peptide-cocktail using autologous DC, compared to Freund's adjuvant, and the mock-vaccinated animals, showed significantly higher IFN-{gamma} production, higher levels of vaccine-specific IFN-{gamma} producing CD4{sup +} cells and significant control of plasma viremia. These results support DC-based vaccine delivery and the utility of the conserved HIV-1 envelope peptide-cocktail, capable of priming strong cell-mediated immunity, for potential inclusion in HIV vaccination strategies.

  1. Ubiquitous Over-Expression of Chromatin Remodeling Factor SRG3 Ameliorates the T Cell-Mediated Exacerbation of EAE by Modulating the Phenotypes of both Dendritic Cells and Macrophages.

    PubMed

    Lee, Sung Won; Park, Hyun Jung; Jeon, Sung Ho; Lee, Changjin; Seong, Rho Hyun; Park, Se-Ho; Hong, Seokmann

    2015-01-01

    Although SWI3-related gene (SRG3), a chromatin remodeling factor, is critical for various biological processes including early embryogenesis and thymocyte development, it is unclear whether SRG3 is involved in the differentiation of CD4+ T cells, the key mediator of adaptive immune responses. Because it is known that experimental autoimmune encephalomyelitis (EAE) development is determined by the activation of CD4+ T helper cells, here, we investigated the role of SRG3 in EAE development using SRG3 transgenic mouse models exhibiting two distinct SRG3 expression patterns: SRG3 expression driven by either the CD2 or β-actin promoter. We found that the outcome of EAE development was completely different depending on the expression pattern of SRG3. The specific over-expression of SRG3 using the CD2 promoter facilitated EAE via the induction of Th1 and Th17 cells, whereas the ubiquitous over-expression of SRG3 using the β-actin promoter inhibited EAE by promoting Th2 differentiation and suppressing Th1 and Th17 differentiation. In addition, the ubiquitous over-expression of SRG3 polarized CD4+ T cell differentiation towards the Th2 phenotype by converting dendritic cells (DCs) or macrophages to Th2 types. SRG3 over-expression not only reduced pro-inflammatory cytokine production by DCs but also shifted macrophages from the inducible nitric oxide synthase (iNOS)-expressing M1 phenotype to the arginase-1-expressing M2 phenotype during EAE. In addition, Th2 differentiation in β-actin-SRG3 Tg mice during EAE was associated with an increase in the basophil and mast cell populations and in IL4 production. Furthermore, the increased frequency of Treg cells in the spinal cord of β-actin-SRG3 Tg mice might induce the suppression of and accelerate the recovery from EAE symptoms. Taken together, our results provide the first evidence supporting the development of a new therapeutic strategy for EAE involving the modulation of SRG3 expression to induce M2 and Th2 polarization

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

    PubMed

    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.

  3. Comparative activity of biodegradable nanoparticles with aluminum adjuvants: antigen uptake by dendritic cells and induction of immune response in mice.

    PubMed

    Uto, Tomofumi; Akagi, Takami; Toyama, Masaaki; Nishi, Yosuke; Shima, Fumiaki; Akashi, Mitsuru; Baba, Masanori

    2011-10-30

    Biodegradable poly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs) are considered to be an excellent antigen carrier. Antigen-carrying γ-PGA NPs were examined for their uptake by murine dendritic cells (DCs) and subsequent induction of antigen-specific immune responses in mice and compared with aluminum (AL) adjuvants. Ovalbumin (OVA)-carrying NPs (FITC-OVA-NPs) were taken up much more efficiently by DCs than OVA alone or its AL-associated form. Both OVA-NPs and OVA+AL were detected in an intracellular lysosome compartment of DCs. Furthermore, the uptake of γ-PGA NPs was inhibited in the presence of pinocytosis and phagocytosis inhibitors. Significantly higher induction of antigen-specific CD8(+) T cells was observed in mice immunized with OVA-carrying γ-PGA NPs than in those immunized with OVA alone, OVA+AL, OVA+3-O-desacyl-4'-monophosphoryl lipid A (MPL), and OVA+AL+MPL. Thus, γ-PGA NPs may have great potential as an effective vaccine carrier and adjuvant for clinical use.

  4. Classical dendritic cells are required for dietary antigen-mediated induction of peripheral T(reg) cells and tolerance.

    PubMed

    Esterházy, Daria; Loschko, Jakob; London, Mariya; Jove, Veronica; Oliveira, Thiago Y; Mucida, Daniel

    2016-05-01

    Oral tolerance prevents pathological inflammatory responses to innocuous foreign antigens by peripheral regulatory T cells (pT(reg) cells). However, whether a particular subset of antigen-presenting cells (APCs) is required during dietary antigen exposure for the 'instruction' of naive CD4(+) T cells to differentiate into pT(reg) cells has not been defined. Using myeloid lineage-specific APC depletion in mice, we found that monocyte-derived APCs were dispensable, while classical dendritic cells (cDCs) were critical, for pT(reg) cell induction and oral tolerance. CD11b(-) cDCs from the gut-draining lymph nodes efficiently induced pT(reg) cells and, conversely, loss of transcription factor IRF8-dependent CD11b(-) cDCs impaired their polarization, although oral tolerance remained intact. These data reveal the hierarchy of cDC subsets in the induction of pT(reg) cells and their redundancy during the development of oral tolerance.

  5. Induction of antigen-specific regulatory T lymphocytes by human dendritic cells expressing the glucocorticoid-induced leucine zipper.

    PubMed

    Hamdi, Haifa; Godot, Véronique; Maillot, Marie-Christine; Prejean, Maria Victoria; Cohen, Nicolas; Krzysiek, Roman; Lemoine, François M; Zou, Weiping; Emilie, Dominique

    2007-07-01

    Dendritic cells (DCs) determine whether antigen presentation leads to immune activation or to tolerance. Tolerance-inducing DCs (also called regulatory DCs) act partly by generating regulatory T lymphocytes (Tregs). The mechanism used by DCs to switch toward regulatory DCs during their differentiation is unclear. We show here that human DCs treated in vitro with glucocorticoids produce the glucocorticoid-induced leucine zipper (GILZ). Antigen presentation by GILZ-expressing DCs generates CD25(high)FOXP3(+)CTLA-4/CD152(+) and interleukin-10-producing Tregs inhibiting the response of CD4(+) and CD8(+) T lymphocytes. This inhibition is specific to the antigen presented, and only proliferating CD4(+) T lymphocytes express the Treg markers. Interleukin-10 is required for Treg induction by GILZ-expressing DCs. It is also needed for the suppressive function of Tregs. Antigen-presenting cells from patients treated with glucocorticoids generate interleukin-10-secreting Tregs ex vivo. These antigen-presenting cells produce GILZ, which is needed for Treg induction. Therefore, GILZ is critical for commitment of DCs to differentiate into regulatory DCs and to the generation of antigen-specific Tregs. This mechanism may contribute to the therapeutic effects of glucocorticoids.

  6. From The Cover: Induction of antiviral immunity requires Toll-like receptor signaling in both stromal and dendritic cell compartments

    NASA Astrophysics Data System (ADS)

    Sato, Ayuko; Iwasaki, Akiko

    2004-11-01

    Pattern recognition by Toll-like receptors (TLRs) is known to be important for the induction of dendritic cell (DC) maturation. DCs, in turn, are critically important in the initiation of T cell responses. However, most viruses do not infect DCs. This recognition system poses a biological problem in ensuring that most viral infections be detected by pattern recognition receptors. Furthermore, it is unknown what, if any, is the contribution of TLRs expressed by cells that are infected by a virus, versus TLRs expressed by DCs, in the initiation of antiviral adaptive immunity. Here we address these issues using a physiologically relevant model of mucosal infection with herpes simplex virus type 2. We demonstrate that innate immune recognition of viral infection occurs in two distinct stages, one at the level of the infected epithelial cells and the other at the level of the noninfected DCs. Importantly, both TLR-mediated recognition events are required for the induction of effector T cells. Our results demonstrate that virally infected tissues instruct DCs to initiate the appropriate class of effector T cell responses and reveal the critical importance of the stromal cells in detecting infectious agents through their own pattern recognition receptors. mucosal immunity | pattern recognition | viral infection

  7. Induction of T helper 3 regulatory cells by dendritic cells infected with porcine reproductive and respiratory syndrome virus

    SciTech Connect

    Silva-Campa, Erika; Flores-Mendoza, Lilian; Resendiz, Monica; Pinelli-Saavedra, Araceli; Mata-Haro, Veronica; Mwangi, Waithaka; Hernandez, Jesus

    2009-05-10

    Delayed development of virus-specific immune response has been observed in pigs infected with the porcine reproductive and respiratory syndrome virus (PRRSV). Several studies support the hypothesis that the PRRSV is capable of modulating porcine immune system, but the mechanisms involved are yet to be defined. In this study, we evaluated the induction of T regulatory cells by PRRSV-infected dendritic cells (DCs). Our results showed that PRRSV-infected DCs significantly increased Foxp3{sup +}CD25{sup +} T cells, an effect that was reversible by IFN-alpha treatment, and this outcome was reproducible using two distinct PRRSV strains. Analysis of the expressed cytokines suggested that the induction of Foxp3{sup +}CD25{sup +} T cells is dependent on TGF-beta but not IL-10. In addition, a significant up-regulation of Foxp3 mRNA, but not TBX21 or GATA3, was detected. Importantly, our results showed that the induced Foxp3{sup +}CD25{sup +} T cells were able to suppress the proliferation of PHA-stimulated PBMCs. The T cells induced by the PRRSV-infected DCs fit the Foxp3{sup +}CD25{sup +} T helper 3 (Th3) regulatory cell phenotype described in the literature. The induction of this cell phenotype depended, at least in part, on PRRSV viability because IFN-alpha treatment or virus inactivation reversed these effects. In conclusion, this data supports the hypothesis that the PRRSV succeeds to establish and replicate in porcine cells early post-infection, in part, by inducing Th3 regulatory cells as a mechanism of modulating the porcine immune system.

  8. Dendritic GIRK channels gate the integration window, plateau potentials and induction of synaptic plasticity in dorsal but not ventral CA1 neurons.

    PubMed

    Malik, Ruchi; Johnston, Daniel

    2017-03-09

    Studies comparing neuronal activity at the dorsal and ventral poles of the hippocampus have shown that the scale of spatial information increases and the precision with which space is represented declines from the dorsal to ventral end. These dorsoventral differences in neuronal output and spatial representation could arise due to differences in computations performed by dorsal and ventral CA1 neurons. In this study, we tested this hypothesis by quantifying the differences in dendritic integration and synaptic plasticity between dorsal and ventral CA1 pyramidal neurons of rat hippocampus. Using a combination of somatic and dendritic patch clamp recordings, we show that the threshold for LTP induction is higher in dorsal CA1 neurons and that a G protein-coupled inward-rectifying potassium channel (GIRK) mediated regulation of dendritic plateau potentials and dendritic excitability underlies this gating. By contrast, similar regulation of LTP is absent in ventral CA1 neurons. Additionally, we show that generation of plateau potentials and LTP induction in dorsal CA1 neurons depends on the coincident activation of Schaffer collateral and temporoammonic inputs at the distal apical dendrites. The ventral CA1 dendrites, however, can generate plateau potentials in response to temporally dispersed excitatory inputs. Overall, our results highlight the dorsoventral differences in dendritic computation that could account for the dorsoventral differences in spatial representation.SIGNIFICANCE STATEMENTThe dorsal and ventral parts of the hippocampus encode spatial information at very different scales. While the place specific firing fields are small and precise at the dorsal end of the hippocampus, neurons at the ventral end have comparatively larger place fields. Here, we show that the dorsal CA1 neurons have a higher threshold for long-term potentiation (LTP) and require coincident timing of excitatory synaptic inputs for the generation of dendritic plateau potentials. By

  9. Dendritic cells derived exosomes migration to spleen and induction of inflammation are regulated by CCR7

    PubMed Central

    Wei, Gao; Jie, Yuan; Haibo, Liu; Chaoneng, Wu; Dong, Huang; Jianbing, Zhu; Junjie, Guo; Leilei, Ma; Hongtao, Shi; Yunzeng, Zou; Junbo, Ge

    2017-01-01

    Mature dendritic cells (DCs) home to secondary lymphoid organs through CC chemokine receptor 7 (CCR7). Exosomes derived from DCs (DC-exos) are reported to migrate to spleen and induce inflammation in vivo. In this study, we demonstrated that mature bone marrow DC-exos can activate immature DC and T cells in vitro. Then we intravenously injected DC-exos into C57BL/6 mice, observing that mature DC-exos accumulated more in spleen than immature DC-exos. These DC-exos in spleen could be uptaken by splenetic DCs and T cells and induce an inflammatory response. We further showed that the increased accumulation of mature DC-exos in spleen was regulated by CCR7, whose reduction led to a decrease of accumulation in spleen and attenuated inflammatory response in serum. These data provide us a new perspective to comprehensively understand exosomes, which might inherit some special functions from their parent cells and exert these functions in vivo. PMID:28223684

  10. The role of myeloid receptors on murine plasmacytoid dendritic cells in induction of type I interferon

    PubMed Central

    Seeds, Rosalind E.; Mukhopadhyay, Subhankar; Jones, Ian M.; Gordon, Siamon; Miller, Joanna L.

    2011-01-01

    This study tested the hypothesis that a set of predominantly myeloid restricted receptors (F4/80, CD36, Dectin-1, CD200 receptor and mannan binding lectins) and the broadly expressed CD200 played a role in a key function of plasmacytoid DC (pDC), virally induced type I interferon (IFN) production. The Dectin-1 ligands zymosan, glucan phosphate and the anti-Dectin-1 monoclonal antibody (mAb) 2A11 had no effect on influenza virus induced IFNα/β production by murine splenic pDC. However, mannan, a broad blocking reagent against mannose specific receptors, inhibited IFNα/β production by pDC in response to inactivated influenza virus. Moreover, viral glycoproteins (influenza virus haemagglutinin and HIV-1 gp120) stimulated IFNα/β production by splenocytes in a mannan-inhibitable manner, implicating the function of a lectin in glycoprotein induced IFN production. Lastly, the effect of CD200 on IFN induction was investigated. CD200 knock-out macrophages produced more IFNα than wild-type macrophages in response to polyI:C, a MyD88-independent stimulus, consistent with CD200's known inhibitory effect on myeloid cells. In contrast, blocking CD200 with an anti-CD200 mAb resulted in reduced IFNα production by pDC-containing splenocytes in response to CpG and influenza virus (MyD88-dependent stimuli). This suggests there could be a differential effect of CD200 on MyD88 dependent and independent IFN induction pathways in pDC and macrophages. This study supports the hypothesis that a mannan-inhibitable lectin and CD200 are involved in virally induced type I IFN induction. PMID:21281752

  11. Induction of human dendritic cell maturation using transfection with RNA encoding a dominant positive toll-like receptor 4.

    PubMed

    Cisco, Robin M; Abdel-Wahab, Zeinab; Dannull, Jens; Nair, Smita; Tyler, Douglas S; Gilboa, Eli; Vieweg, Johannes; Daaka, Yehia; Pruitt, Scott K

    2004-06-01

    Maturation of dendritic cells (DC) is critical for the induction of Ag-specific immunity. Ag-loaded DC matured with LPS, which mediates its effects by binding to Toll-like receptor 4 (TLR4), induce Ag-specific CTL in vitro and in vivo in animal models. However, clinical use of LPS is limited due to potential toxicity. Therefore, we sought to mimic the maturation-inducing effects of LPS on DC by stimulating TLR4-mediated signaling in the absence of exogenous LPS. We developed a constitutively active TLR4 (caTLR4) and demonstrated that transfection of human DC with RNA encoding caTLR4 led to IL-12 and TNF-alpha secretion. Transfection with caTLR4 RNA also induced a mature DC phenotype. Functionally, transfection of DC with caTLR4 RNA enhanced allostimulation of CD4(+) T cells. DC transfected with RNA encoding the MART (Melan-A/MART-1) melanoma Ag were then used to stimulate T cells in vitro. Cotransfection of these DC with caTLR4 RNA enhanced the generation of MART-specific CTL. This CTL activity was superior to that seen when DC maturation was induced using either LPS or a standard mixture of cytokines (TNF-alpha, IL-6, IL-1beta, and PGE(2)). We conclude that transfection of DC with RNA encoding a functional signaling protein, such as caTLR4, may provide a new tool for studying TLR signaling in DC and may be a promising approach for the induction of DC maturation for tumor immunotherapy.

  12. Induction of Dendritic Cell Maturation and Activation by a Potential Adjuvant, 2-Hydroxypropyl-β-Cyclodextrin

    PubMed Central

    Kim, Sun Kyung; Yun, Cheol-Heui; Han, Seung Hyun

    2016-01-01

    2-Hydroxypropyl-β-cyclodextrin (HP-β-CD) is a chemically modified cyclic oligosaccharide produced from starch that is commonly used as an excipient. Although HP-β-CD has been suggested as a potential adjuvant for vaccines, its immunological properties and mechanism of action have yet to be characterized. In the present study, we investigated the maturation and activation of human dendritic cells (DCs) treated with HP-β-CD. We found that DCs stimulated with HP-β-CD exhibited a remarkable upregulation of costimulatory molecules, MHC proteins, and PD-L1/L2. In addition, the production of cytokines, such as TNF-α, IL-6, and IL-10, was modestly increased in DCs when treated with HP-β-CD. Furthermore, HP-β-CD-sensitized DCs markedly induced the proliferation and activation of autologous T lymphocytes. HP-β-CD also induced a lipid raft formation in DCs. In contrast, filipin, a lipid raft inhibitor, attenuated HP-β-CD-induced DC maturation, the cytokine expression, and the T lymphocyte-stimulating activities. To determine the in vivo relevance of the results, we investigated the adjuvanticity of HP-β-CD and the modulation of DCs in a mouse footpad immunization model. When mice were immunized with ovalbumin in the presence of HP-β-CD through a hind footpad, serum ovalbumin-specific antibodies were markedly elevated. Concomitantly, DC populations expressing CD11c and MHC class II were increased in the draining lymph nodes, and the expression of costimulatory molecules was upregulated. Collectively, our data suggest that HP-β-CD induces phenotypic and functional maturation of DCs mainly mediated through lipid raft formation, which might mediate the adjuvanticity of HP-β-CD. PMID:27812358

  13. PD-L2 induction on dendritic cells exposed to Mycobacterium avium downregulates BCG-specific T cell response.

    PubMed

    Mendoza-Coronel, Elizabeth; Camacho-Sandoval, Rosa; Bonifaz, Laura C; López-Vidal, Yolanda

    2011-01-01

    The exposure to certain species of Nontuberculous Mycobacteria (NTM) can modulate the immune response induced by Mycobacterium bovis BCG. Mycobacterium avium has been postulated as a weak inducer of dendritic cell (DC) maturation. However, how the DC exposure to M. avium could contribute to the modulation of a BCG-specific CD4+ T cell response and the molecules involved remain unknown. Here, we exposed bone marrow-derived DCs (BMDCs) to M. avium either prior to exposure to BCG or as a unique stimulus. We found that M. avium induces high expression of PD-L2 (B7-DC) in BMDCs. This was dependent on IL-10 production through the TLR2-p38 MAPK signaling pathway. Exposure to M. avium prior to BCG results in BMDCs that do not express co-stimulatory molecules and pro-inflammatory cytokines, while the expression of PD-L2 and IL-10 was maintained. BMDCs exposed to M. avium impaired the activation of BCG-specific T cells through the PD-1: PD-L interaction. This suggests that a M. avium-induced phenotype in DCs might be implicated in the induction of mechanisms of tolerance that could impact the T cell response induced by BCG vaccination.

  14. DNA vaccination strategy targets epidermal dendritic cells, initiating their migration and induction of a host immune response

    PubMed Central

    Smith, Trevor RF; Schultheis, Katherine; Kiosses, William B; Amante, Dinah H; Mendoza, Janess M; Stone, John C; McCoy, Jay R; Sardesai, Niranjan Y; Broderick, Kate E

    2014-01-01

    The immunocompetence and clinical accessibility of dermal tissue offers an appropriate and attractive target for vaccination. We previously demonstrated that pDNA injection into the skin in combination with surface electroporation (SEP), results in rapid and robust expression of the encoded antigen in the epidermis. Here, we demonstrate that intradermally EP-enhanced pDNA vaccination results in the rapid induction of a host humoral immune response. In the dermally relevant guinea pig model, we used high-resolution laser scanning confocal microscopy to observe direct dendritic cell (DC) transfections in the epidermis, to determine the migration kinetics of these cells from the epidermal layer into the dermis, and to follow them sequentially to the immediate draining lymph nodes. Furthermore, we delineate the relationship between the migration of directly transfected epidermal DCs and the generation of the host immune response. In summary, these data indicate that direct presentation of antigen to the immune system by DCs through SEP-based in vivo transfection in the epidermis, is related to the generation of a humoral immune response. PMID:26052522

  15. Serum amyloid A chemoattracts immature dendritic cells and indirectly provokes monocyte chemotaxis by induction of cooperating CC and CXC chemokines.

    PubMed

    Gouwy, Mieke; De Buck, Mieke; Pörtner, Noëmie; Opdenakker, Ghislain; Proost, Paul; Struyf, Sofie; Van Damme, Jo

    2015-01-01

    Serum amyloid A (SAA) is an acute phase protein that is upregulated in inflammatory diseases and chemoattracts monocytes, lymphocytes, and granulocytes via its G protein-coupled receptor formyl peptide receptor like 1/formyl peptide receptor 2 (FPRL1/FPR2). Here, we demonstrated that the SAA1α isoform also chemoattracts monocyte-derived immature dendritic cells (DCs) in the Boyden and μ-slide chemotaxis assay and that its chemotactic activity for monocytes and DCs was indirectly mediated via rapid chemokine induction. Indeed, SAA1 induced significant amounts (≥5 ng/mL) of macrophage inflammatory protein-1α/CC chemokine ligand 3 (MIP-1α/CCL3) and interleukin-8/CXC chemokine ligand 8 (IL-8/CXCL8) in monocytes and DCs in a dose-dependent manner within 3 h. However, SAA1 also directly activated monocytes and DCs for signaling and chemotaxis without chemokine interference. SAA1-induced monocyte migration was nevertheless significantly prevented (60-80% inhibition) in the constant presence of desensitizing exogenous MIP-1α/CCL3, neutralizing anti-MIP-1α/CCL3 antibody, or a combination of CC chemokine receptor 1 (CCR1) and CCR5 antagonists, indicating that this endogenously produced CC chemokine was indirectly contributing to SAA1-mediated chemotaxis. Further, anti-IL-8/CXCL8 antibody neutralized SAA1-induced monocyte migration, suggesting that endogenous IL-8/CXCL8 acted in concert with MIP-1α/CCL3. This explained why SAA1 failed to synergize with exogenously added MIP-1α/CCL3 or stromal cell-derived factor-1α (SDF-1α)/CXCL12 in monocyte and DC chemotaxis. In addition to direct leukocyte activation, SAA1 induces a chemotactic cascade mediated by expression of cooperating chemokines to prolong leukocyte recruitment to the inflammatory site.

  16. The role of ICOS in directing T cell responses: ICOS-dependent induction of T cell anergy by tolerogenic dendritic cells.

    PubMed

    Tuettenberg, Andrea; Huter, Eva; Hubo, Mario; Horn, Julia; Knop, Jürgen; Grimbacher, Bodo; Kroczek, Richard A; Stoll, Sabine; Jonuleit, Helmut

    2009-03-15

    Tolerogenic dendritic cells (DC) play an important role in maintaining peripheral T cell tolerance in steady-state conditions through induction of anergic, IL-10-producing T cells with suppressive properties. ICOS, an activation-induced member of the CD28 family on T cells, is involved in the induction of IL-10, which itself could contribute to induction of anergy and development of suppressive T cells. Therefore, we analyzed the functional role of ICOS in the differentiation process of human CD4(+) T cells upon their interaction with tolerogenic DC. We compared the functional properties of CD4(+) T cells from healthy volunteers and ICOS-deficient patients after stimulation with tolerogenic DC. We report that induction of T cell anergy and suppressive capacity is completely blocked after knockdown of ICOS expression in T cells as well as after blocking of ICOS-ICOS ligand interaction in DC/T cell cocultures. Moreover, CD4(+) T cells from ICOS-deficient patients were completely resistant to anergy induction and differentiation into suppressive T cells even after supplementation of IL-10. Furthermore, ICOS/ICOS ligand interaction stabilizes IL-10R expression on T cells and thus renders them sensitive to IL-10 effects. Taken together, these results indicate a crucial role for ICOS in the induction of peripheral tolerance maintained by tolerogenic DC mediated mostly via an IL-10-independent mechanism.

  17. Gene expression profiles identify both MyD88-independent and MyD88-dependent pathways involved in the maturation of dendritic cells mediated by heparan sulfate: A novel adjuvant

    PubMed Central

    Wu, Meini; Wang, Haixuan; Shi, Jiandong; Sun, Jing; Duan, Zhiqing; Li, Yanhan; Li, Jianfang; Hu, Ningzhu; Wei, Yiju; Chen, Yang; Hu, Yunzhang

    2015-01-01

    The traditional vaccine adjuvant research is mainly based on the trial and error method, and the mechanisms underlying the immune system stimulation remaining largely unknown. We previously demonstrated that heparan sulfate (HS), a TLR-4 ligand and endogenous danger signal, effectively enhanced humoral and cellular immune responses in mice immunized by HBsAg. This study aimed to evaluate whether HS induces better humoral immune responses against inactivated Hepatitis A or Rabies Vaccines, respectively, compared with traditional adjuvants (e.g. Alum and complete Freund's adjuvant). In order to investigate the molecular mechanisms of its adjuvanticity, the gene expression pattern of peripheral blood monocytes derived DCs (dendritic cells) stimulated with HS was analyzed at different times points. Total RNA was hybridized to Agilent SurePrint G3 Human Gene Expression 8 × 60 K one-color oligo-microarray. Through intersection analysis of the microarray results, we found that the Toll-like receptor signaling pathway was significantly activated, and NF-kB, TRAF3 and IRF7 were activated as early as 12 h, and MyD88 was activated at 48 h post-stimulation. Furthermore, the expression of the surface marker CD83 and the co-stimulatory molecules CD80 and CD86 was up-regulated as early as 24 h. Therefore, we speculated that HS-induced human monocyte-derived DC maturation may occur through both MyD88-independent and dependent pathways, but primarily through the former (TRIF pathway). These data provide an important basis for understanding the mechanisms underlying HS enhancement of the immune response. PMID:25668674

  18. Topical vaccination with functionalized particles targeting dendritic cells.

    PubMed

    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.

  19. An essential protective role of IL-10 in the immunological mechanism underlying resistance vs susceptibility to lupus induction by dendritic cells and dying cells

    PubMed Central

    Ling, Guang-Sheng; Cook, H. Terence; Botto, Marina; Lau, Yu-Lung

    2011-01-01

    Objective. To define the role of IL-10 in lupus pathogenesis, and to understand the immunological mechanisms underlying resistance vs susceptibility to lupus disease induction by dendritic cells (DCs) and dying cells. Methods. Groups of IL-10-deficient and normal C57BL/6 mice were injected with syngenic DCs that had ingested necrotic cells prepared by either freeze–thaw cycle (DC/necF/T) or heat shock (DC/necH/S) procedures, or with DC or necrotic cells alone, or with PBS only. Disease development, including proteinuria and renal pathological changes, was monitored. Levels of autoantibodies against different lupus-associated nuclear antigens were measured by ELISAs, and IC deposition in the kidneys was confirmed by immunostaining. Results. No significant proteinuria was detected in the mice. However, striking renal pathological changes typical of IC-mediated GN were consistently observed in the DC/necF/T-treated IL-10−/− mice. These included glomerular hypercellularity and macrophage infiltration, renal IC deposition, circulating kidney-reactive autoantibodies and the presence of immunoglobulin G2 isotype-specific antibody complexes in the diseased kidneys. We demonstrated further that host-derived IL-10 was primarily responsible for protecting against the induction of pathogenic Th1 type of autoantibody responses in the mice. Conclusion. IL-10 protects against the induction of lupus-like renal end-organ damage by down-regulating pathogenic Th1 responses. PMID:21727182

  20. Protein kinase Mζ is essential for the induction and maintenance of dopamine-induced long-term potentiation in apical CA1 dendrites

    PubMed Central

    Navakkode, Sheeja; Sajikumar, Sreedharan; Sacktor, Todd Charlton; Frey, Julietta U.

    2010-01-01

    Dopaminergic D1/D5-receptor-mediated processes are important for certain forms of memory as well as for a cellular model of memory, hippocampal long-term potentiation (LTP) in the CA1 region of the hippocampus. D1/D5-receptor function is required for the induction of the protein synthesis-dependent maintenance of CA1-LTP (L-LTP) through activation of the cAMP/PKA-pathway. In earlier studies we had reported a synergistic interaction of D1/D5-receptor function and N-methyl-D-aspartate (NMDA)-receptors for L-LTP. Furthermore, we have found the requirement of the atypical protein kinase C isoform, protein kinase Mζ (PKMζ) for conventional electrically induced L-LTP, in which PKMζ has been identified as a LTP-specific plasticity-related protein (PRP) in apical CA1-dendrites. Here, we investigated whether the dopaminergic pathway activates PKMζ. We found that application of dopamine (DA) evokes a protein synthesis-dependent LTP that requires synergistic NMDA-receptor activation and protein synthesis in apical CA1-dendrites. We identified PKMζ as a DA-induced PRP, which exerted its action at activated synaptic inputs by processes of synaptic tagging. PMID:21084457

  1. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    PubMed Central

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho

    2016-01-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  2. Induction of Regulatory Dendritic Cells by Lactobacillus paracasei L9 Prevents Allergic Sensitization to Bovine β-Lactoglobulin in Mice.

    PubMed

    Yang, Jing; Ren, Fazheng; Zhang, Hao; Jiang, Lu; Hao, Yanling; Luo, Xugang

    2015-10-01

    Supplementation with probiotics can protect against the development of food allergies by modulating the host immune response; however, the mechanisms are not fully understood. The objective of this study was to investigate the allergy-reducing effects of regulatory dendritic cells (regDCs) induced by Lactobacillus paracasei L9 (L9) in β-lactoglobulin (BLG)- sensitized mice. The L9 supplement suppressed the aberrant balance of Th1/Th2 responses to BLG in mice, via upregulation of the CD4+CD25+Foxp3+Treg cell responses. The amount of CD4+CD25+Foxp3+Treg cells in mesenteric lymph nodes increased by 51.85%. Furthermore, administration of L9 significantly induced the expression of CD103 and reduced the maturation status of DCs in mesenteric lymph nodes, Peyer's patches, and spleen. Bone marrow-derived dendritic cells (BM-DCs) were activated by L9 in vitro, with an approximate 1.31-fold and 19.57-fold increase in expression of CD103 in CD11c+DCs and the level of IL-10 production, respectively, while the expression of CD86 did not change significantly. These data demonstrate that L9 reduced the BLG allergic sensitization, likely through regDCs mediated active suppression.

  3. A critical role for Syk protein tyrosine kinase in Fc receptor-mediated antigen presentation and induction of dendritic cell maturation.

    PubMed

    Sedlik, Christine; Orbach, Daniel; Veron, Philippe; Schweighoffer, Edina; Colucci, Francesco; Gamberale, Romina; Ioan-Facsinay, Andrea; Verbeek, Sjef; Ricciardi-Castagnoli, Paola; Bonnerot, Christian; Tybulewicz, Victor L J; Di Santo, James; Amigorena, Sebastian

    2003-01-15

    Dendritic cells (DCs) are the only APCs capable of initiating adaptive immune responses. The initiation of immune responses requires that DCs 1) internalize and present Ags; and 2) undergo a differentiation process, called "maturation", which transforms DCs into efficient APCs. DC maturation may be initiated by the engagement of different surface receptors, including certain cytokine receptors (such as TNFR), Toll-like receptors, CD40, and FcRs. The early activation events that link receptor engagement and DC maturation are not well characterized. We found that FcR engagement by immune complexes induced the phosphorylation of Syk, a protein tyrosine kinase acting immediately downstream of FcRs. Syk was dispensable for DC differentiation in vitro and in vivo, but was strictly required for immune complexes internalization and subsequent Ag presentation to T lymphocytes. Importantly, Syk was also required for the induction of DC maturation and IL-12 production after FcR engagement, but not after engagement of other surface receptors, such as TNFR or Toll-like receptors. Therefore, protein tyrosine phosphorylation by Syk represents a novel pathway for the induction of DC maturation.

  4. Interleukin-27 Enhances the Potential of Reactive Oxygen Species Generation from Monocyte-derived Macrophages and Dendritic cells by Induction of p47phox

    PubMed Central

    Sowrirajan, Bharatwaj; Saito, Yoshiro; Poudyal, Deepak; Chen, Qian; Sui, Hongyan; DeRavin, Suk See; Imamichi, Hiromi; Sato, Toyotaka; Kuhns, Douglas B.; Noguchi, Noriko; Malech, Harry L.; Lane, H. Clifford; Imamichi, Tomozumi

    2017-01-01

    Interleukin (IL)-27, a member of the IL-12 cytokine family, plays an important and diverse role in the function of the immune system. We have previously demonstrated that IL-27 is an anti-viral cytokine which inhibits HIV-1, HIV-2, Influenza virus and herpes simplex virus infection, and enhances the potential of reactive oxygen species (ROS) generating activity during differentiation of monocytes to macrophages. In this study, we further investigated the mechanism of the enhanced potential for ROS generation by IL-27. Real time PCR, western blot and knock down assays demonstrate that IL-27 is able to enhance the potential of superoxide production not only during differentiation but also in terminally differentiated-macrophages and immature dendritic cells (iDC) in association with the induction of p47phox, a cytosolic component of the ROS producing enzyme, NADPH oxidase, and the increase in amounts of phosphorylated p47phox upon stimulation. We also demonstrate that IL-27 is able to induce extracellular superoxide dismutase during differentiation of monocytes but not in terminal differentiated macrophages. Since ROS plays an important role in a variety of inflammation, our data demonstrate that IL-27 is a potent regulator of ROS induction and may be a novel therapeutic target. PMID:28240310

  5. Rapid dendritic cell activation and resistance to allotolerance induction in anti-CD154-treated mice receiving CD47-deficient donor-specific transfusion.

    PubMed

    Wang, Yuantao; Wang, Hui; Bronson, Roderick; Fu, Yaowen; Yang, Yong-Guang

    2014-03-01

    CD47-SIRPα signaling plays an important role in regulating macrophage and dendritic cell (DC) activation. Here we investigated the role of CD47 expression on donor cells in tolerance induction by combined treatment with donor-specific transfusion (DST) plus anti-CD154 mAb in a mouse model of fully MHC-mismatched heart allotransplantation. The majority of BALB/c recipient mice that received anti-CD154 and CD47(+/+) B6 splenocytes (DST) showed indefinite donor heart survival (median survival time, MST > 150 days). Donor heart survival was improved in anti-CD154-treated BALB/c mice that received CD47(+/-) (MST = 90 days) or CD47(-/-) B6 DST (MST = 42 days) when compared to the nontreated (MST = 7 days) and anti-CD154 alone-treated (MST = 15 days) controls, but significantly reduced when compared to mice receiving anti-CD154 plus CD47(+/+) B6 DST. Recipient mice treated with anti-CD154 plus CD47(-/-) or CD47(+/-) DST also showed significantly increased antidonor, but not anti-third-party, MLR responses compared to those receiving anti-CD154 and CD47(+/+) DST. Furthermore, CD47(-/-) DST induced rapid activation of CD11c(hi)SIRPα(hi)CD8α(-) DCs via a mechanism independent of donor alloantigens. These results demonstrated that CD47 expression on donor cells is essential to the success of tolerance induction by combined therapy with DST and CD40/CD154 blockade.

  6. TLR-independent induction of dendritic cell maturation and adaptive immunity by negative-strand RNA viruses.

    PubMed

    López, Carolina B; Moltedo, Bruno; Alexopoulou, Lena; Bonifaz, Laura; Flavell, Richard A; Moran, Thomas M

    2004-12-01

    TLR signaling leads to dendritic cell (DC) maturation and immunity to diverse pathogens. The stimulation of TLRs by conserved viral structures is the only described mechanism leading to DC maturation after a virus infection. In this report, we demonstrate that mouse myeloid DCs mature normally after in vivo and in vitro infection with Sendai virus (SeV) in the absence of TLR3, 7, 8, or 9 signaling. DC maturation by SeV requires virus replication not necessary for TLR-mediated triggering. Moreover, DCs deficient in TLR signaling efficiently prime for Th1 immunity after infection with influenza or SeV, generating IFN-gamma-producing T cells, CTLs and antiviral Abs. We have previously demonstrated that SeV induces DC maturation independently of the presence of type I IFN, which has been reported to mature DCs in a TLR-independent manner. The data presented here provide evidence for the existence of a novel intracellular pathway independent of TLR-mediated signaling responsible for live virus triggering of DC maturation and demonstrate its critical role in the onset of antiviral immunity. The revelation of this pathway should stimulate invigorating research into the mechanism for virus-induced DC maturation and immunity.

  7. Interleukin 10 (IL-10)-mediated Immunosuppression: MARCH-I INDUCTION REGULATES ANTIGEN PRESENTATION BY MACROPHAGES BUT NOT DENDRITIC CELLS.

    PubMed

    Mittal, Sharad K; Cho, Kyung-Jin; Ishido, Satoshi; Roche, Paul A

    2015-11-06

    Efficient immune responses require regulated antigen presentation to CD4 T cells. IL-10 inhibits the ability of dendritic cells (DCs) and macrophages to stimulate antigen-specific CD4 T cells; however, the mechanisms by which IL-10 suppresses antigen presentation remain poorly understood. We now report that IL-10 stimulates expression of the E3 ubiquitin ligase March-I in activated macrophages, thereby down-regulating MHC-II, CD86, and antigen presentation to CD4 T cells. By contrast, IL-10 does not stimulate March-I expression in DCs, does not suppress MHC-II or CD86 expression on either resting or activated DCs, and does not affect antigen presentation by activated DCs. IL-10 does, however, inhibit the process of DC activation itself, thereby reducing the efficiency of antigen presentation in a March-I-independent manner. Thus, IL-10 suppression of antigen presenting cell function in macrophages is March-I-dependent, whereas in DCs, suppression is March- I-independent.

  8. Transient systemic inflammation does not alter the induction of tolerance to gastric autoantigens by migratory dendritic cells.

    PubMed

    Bourges, Dorothée; Ross, Ellen M; Allen, Stacey; Read, Simon; Houghton, Fiona J; Bedoui, Sammy; Boon, Louis; Gleeson, Paul A; van Driel, Ian R

    2014-06-01

    It has been proposed that activation of dendritic cells (DCs) presenting self-antigens during inflammation may lead to activation of autoreactive T cells and the development of autoimmunity. To test this hypothesis, we examined the presentation of the autoantigen recognized in autoimmune gastritis, gastric H(+)/K(+) ATPase, which is naturally expressed in the stomach and is constitutively presented in the stomach-draining lymph nodes. Systemic administration to mice of the TLR9 agonist CpG DNA, agonist anti-CD40 Ab, or TLR4 agonist LPS all failed to abrogate the process of peripheral clonal deletion of H(+)/K(+) ATPase-specific CD4 T cells or promote the development of autoimmune gastritis. We demonstrated that migratory DCs from the stomach-draining lymph nodes are the only DC subset capable of constitutively presenting the endogenous gastric H(+)/K(+) ATPase autoantigen in its normal physiological context. Analysis of costimulatory molecules indicated that, relative to resident DCs, migratory DCs displayed a partially activated phenotype in the steady state. Furthermore, migratory DCs were refractory to stimulation by transient exposure to TLR agonists, as they failed to upregulate costimulatory molecules, secrete significant amounts of inflammatory cytokines, or induce differentiation of effector T cells. Together, these data show that transient systemic inflammation failed to break tolerance to the gastric autoantigen, as migratory DCs presenting the gastric autoantigen remain tolerogenic under such conditions, demonstrating the robust nature of peripheral tolerance.

  9. Extranodal induction of therapeutic immunity in the tumor microenvironment after intratumoral delivery of Tbet gene-modified dendritic cells.

    PubMed

    Chen, L; Taylor, J L; Sabins, N C; Lowe, D B; Qu, Y; You, Z; Storkus, W J

    2013-08-01

    Murine dendritic cells (DC) transduced to express the Type-1 transactivator T-bet (i.e. mDC.Tbet) and delivered intratumorally as a therapy are superior to control wild-type DC in slowing the growth of established subcutaneous MCA205 sarcomas in vivo. Optimal antitumor efficacy of mDC.Tbet-based gene therapy was dependent on host natural killer (NK) cells and CD8(+) T cells, and required mDC.Tbet expression of major histocompatibility complex class I molecules, but was independent of the capacity of the injected mDC.Tbet to produce proinflammatory cytokines (interleukin-12 family members or interferon-γ) or to migrate to tumor-draining lymph nodes based on CCR7 ligand chemokine recruitment. Conditional (CD11c-DTR) or genetic (BATF3(-/-)) deficiency in host antigen-crosspresenting DC did not diminish the therapeutic action of intratumorally delivered wild-type mDC.Tbet. Interestingly, we observed that intratumoral delivery of mDC.Tbet (versus control mDC.Null) promoted the acute infiltration of NK cells and naive CD45RB(+) T cells into the tumor microenvironment (TME) in association with elevated expression of NK- and T-cell-recruiting chemokines by mDC.Tbet. When taken together, our data support a paradigm for extranodal (cross)priming of therapeutic Type-1 immunity in the TME after intratumoral delivery of mDC.Tbet-based gene therapy.

  10. Tolerogenic Plasmacytoid Dendritic Cells Control Paracoccidioides brasiliensis Infection by Inducting Regulatory T Cells in an IDO-Dependent Manner

    PubMed Central

    de Araújo, Eliseu Frank; Medeiros, Daniella Helena; Condino-Neto, Antônio

    2016-01-01

    Plasmacytoid dendritic cells (pDCs), considered critical for immunity against viruses, were recently associated with defense mechanisms against fungal infections. However, the immunomodulatory function of pDCs in pulmonary paracoccidiodomycosis (PCM), an endemic fungal infection of Latin America, has been poorly defined. Here, we investigated the role of pDCs in the pathogenesis of PCM caused by the infection of 129Sv mice with 1 x 106 P. brasiliensis-yeasts. In vitro experiments showed that P. brasiliensis infection induces the maturation of pDCs and elevated synthesis of TNF-α and IFN-β. The in vivo infection caused a significant influx of pDCs to the lungs and increased levels of pulmonary type I IFN. Depletion of pDCs by a specific monoclonal antibody resulted in a less severe infection, reduced tissue pathology and increased survival time of infected mice. An increased influx of macrophages and neutrophils and elevated presence of CD4+ and CD8+ T lymphocytes expressing IFN-γ and IL-17 in the lungs of pDC-depleted mice were also observed. These findings were concomitant with decreased frequency of Treg cells and reduced levels of immunoregulatory cytokines such as IL-10, TGF-β, IL-27 and IL-35. Importantly, P. brasilienis infection increased the numbers of pulmonary pDCs expressing indoleamine 2,3-dioxygenase-1 (IDO), an enzyme with immunoregulatory properties, that were reduced following pDC depletion. In agreement, an increased immunogenic activity of infected pDCs was observed when IDO-deficient or IDO-inhibited pDCs were employed in co-cultures with lymphocytes Altogether, our results suggest that in pulmonary PCM pDCs exert a tolerogenic function by an IDO-mediated mechanism that increases Treg activity. PMID:27992577

  11. Disruption of TIM-4 in dendritic cell ameliorates hepatic warm IR injury through the induction of regulatory T cells.

    PubMed

    Li, Ji; Zhao, Xin; Liu, Xiaoliang; Liu, Huanqiu

    2015-08-01

    Hepatic ischaemia reperfusion (IR) injury results from the infiltration of multiple immune cells especially dendritic cells (DC). T-cell immunoglobulin-domain and mucin-domain 4 (TIM-4) is a type I cell-surface glycoprotein which is extensively expressed on antigen presenting cells (APC) like DC and macrophages. TIM-4 has been demonstrated to be implicated in mucosal allergy, skin allograft rejection and tumour-immune tolerance. However, the role of TIM-4 expressed on DC in hepatic IR injury remains largely unknown. In the present study, we aimed to investigate whether and how DC expressed TIM-4 was involved in hepatic IR injury. With segmental hepatic warm ischaemia mice models, we demonstrated that promoted DC infiltration and increased TIM-4 expression were induced by hepatic IR. Blockade of TIM-4 by anti-TIM-4 mAb (0.35mg/mouse) markedly ameliorated hepatic injury and reduced inflammatory cytokine secretion. Furthermore, in a DC:CD4+ T cell co-culture system, blockade of TIM-4 on DC significantly inhibited T helper-2 cell differentiation and facilitated induced CD4+ CD25+ Foxp3+ T regulatory cell (iTreg) expansion. Interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (Stat 6) signalling was shown to be impeded by TIM-4 blockade and involved in iTreg generation. Additionally, adoptive transfer of iTreg produced by TIM-4 blockade into hepatic IR mice models remarkably attenuated liver injury. We conclude that TIM-4 on DC play a critical role in hepatic IR injury and may be an efficient target for the prevention of liver or other organ IR injury.

  12. Induction of suppressive phenotype in monocyte-derived dendritic cells by leukemic cell products and IL-1β.

    PubMed

    Motta, Juliana Maria; Sperandio, Aline; Castelo-Branco, Morgana Teixeira Lima; Rumjanek, Vivian Mary

    2014-07-01

    Professional antigen-presenting cells, dendritic cells (DCs) play an important role in controlling tumors. It is known that solid tumor cell products inhibit DC differentiation. Recently a similar effect produced by leukemic cell products has been demonstrated. In this case, leukemic cell products induced the secretion of IL-1β by monocytes undergoing differentiation. The aim of the present work was to characterize and to compare the development of monocyte-derived DCs under the influence of leukemic cell products (K562 supernatant) or exogenous IL-1β. It became clear that leukemic cell products and IL-1β differentially modulate some of the parameters studied on monocytes stimulated to differentiate into DCs. In the presence of K562 supernatant, the expression of the macrophage markers CD16 and CD68 were higher than in immature DCs control. Contrasting with IL-1β, leukemic cell products possibly favor the development of cells with macrophage markers. In addition, CD80 and CD83 expressions were also higher in the presence of tumor supernatant whereas HLA-DR was lower. In the presence of IL-1β, only CD80 was increased. Furthermore, it was observed that when monocytes were induced to differentiate into DCs in the presence of tumor supernatant and then activated, they expressed less CD80 and CD83 than activated DCs control. A reduced expression of CD83 following activation was also seen in cells differentiated with IL-1β. TGF-β and VEGF were found in the tumor supernatants. Moreover, the exposure to tumor supernatant or IL-1β stimulated IL-10 production while decreased IL-12 production by activated DCs. Finally, these results suggest that the addition of products released by leukemic cells or, more discreetly, the addition of IL-1β affects DC differentiation, inducing a suppressive phenotype.

  13. Induction of protective immunity against Eimeria tenella, Eimeria maxima, and Eimeria acervulina infections using dendritic cell-derived exosomes.

    PubMed

    del Cacho, Emilio; Gallego, Margarita; Lee, Sung Hyen; Lillehoj, Hyun Soon; Quilez, Joaquin; Lillehoj, Erik P; Sánchez-Acedo, Caridad

    2012-05-01

    This study describes a novel immunization strategy against avian coccidiosis using exosomes derived from Eimeria parasite antigen (Ag)-loaded dendritic cells (DCs). Chicken intestinal DCs were isolated and pulsed in vitro with a mixture of sporozoite-extracted Ags from Eimeria tenella, E. maxima, and E. acervulina, and the cell-derived exosomes were isolated. Chickens were nonimmunized or immunized intramuscularly with exosomes and subsequently noninfected or coinfected with E. tenella, E. maxima, and E. acervulina oocysts. Immune parameters compared among the nonimmunized/noninfected, nonimmunized/infected, and immunized/infected groups were the numbers of cells secreting T(h)1 cytokines, T(h)2 cytokines, interleukin-16 (IL-16), and Ag-reactive antibodies in vitro and in vivo readouts of protective immunity against Eimeria infection. Cecal tonsils, Peyer's patches, and spleens of immunized and infected chickens had increased numbers of cells secreting the IL-16 and the T(h)1 cytokines IL-2 and gamma interferon, greater Ag-stimulated proliferative responses, and higher numbers of Ag-reactive IgG- and IgA-producing cells following in vitro stimulation with the sporozoite Ags compared with the nonimmunized/noninfected and nonimmunized/infected controls. In contrast, the numbers of cells secreting the T(h)2 cytokines IL-4 and IL-10 were diminished in immunized and infected chickens compared with the nonimmunized/noninfected and the nonimmunized/infected controls. Chickens immunized with Ag-loaded exosomes and infected in vivo with Eimeria oocysts had increased body weight gains, reduced feed conversion ratios, diminished fecal oocyst shedding, lessened intestinal lesion scores, and reduced mortality compared with the nonimmunized/infected controls. These results suggest that successful field vaccination against avian coccidiosis using exosomes derived from DCs incubated with Ags isolated from Eimeria species may be possible.

  14. Induction of Cytomegalovirus-Specific T Cell Responses in Healthy Volunteers and Allogeneic Stem Cell Recipients Using Vaccination With Messenger RNA–Transfected Dendritic Cells

    PubMed Central

    Van Craenenbroeck, Amaryllis H.; Smits, Evelien L.J.; Anguille, Sébastien; Van de Velde, Ann; Stein, Barbara; Braeckman, Tessa; Van Camp, Kirsten; Nijs, Griet; Ieven, Margareta; Goossens, Herman; Berneman, Zwi N.; Van Tendeloo, Viggo F.I.; Verpooten, Gert A.; Van Damme, Pierre; Cools, Nathalie

    2015-01-01

    Background Infection with human cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ and hematopoietic stem cell transplant (HSCT) recipients. Methods The present study explored the safety, feasibility, and immunogenicity of CMV pp65 messenger RNA–loaded autologous monocyte-derived dendritic cells (DC) as a cellular vaccine for active immunization in healthy volunteers and allogeneic HSCT recipients. Four CMV-seronegative healthy volunteers and three allogeneic HSCT recipients were included in the study. Four clinical-grade autologous monocyte-derived DC vaccines were prepared after a single leukapheresis procedure and administered intradermally at a weekly interval. Results De novo induction of CMV-specific T-cell responses was detected in three of four healthy volunteers without serious adverse events. Of the HSCT recipients, none developed CMV disease and one of two patients displayed a remarkable threefold increase in CMV pp65-specific T cells on completion of the DC vaccination trial. Conclusion In conclusion, our DC vaccination strategy induced or expanded a CMV-specific cellular response in four of six efficacy-evaluable study subjects, providing a base for its further exploration in larger cohorts. PMID:25050468

  15. CD8α+β− and CD8α+β+ plasmacytoid dendritic cells induce Foxp3+ regulatory T cells and prevent the induction of airway hyperreactivity

    PubMed Central

    Lombardi, Vincent; Speak, Anneliese O.; Kerzerho, Jérôme; Szely, Natacha; Akbari, Omid

    2012-01-01

    Dendritic cells (DCs) control the balance between protection against pathogens and tolerance to innocuous or self-antigens. Here, we demonstrate for the first time that mouse plasmacytoid DCs (pDCs) can be segregated into three distinct populations, exhibiting phenotypic and functional differences, according to their surface expression of CD8α or CD8β as CD8α−β−, CD8α+β− or CD8α+β+. In a mouse model of lung inflammation, adoptive transfer of CD8α+β− or CD8α+β+ pDCs prevents the development of airway hyperreactivity. The tolerogenic features of these subsets are associated with increased production of retinoic acid, which leads to the enhanced induction of Foxp3+ regulatory T cells compared to CD8α−β− pDCs. Our data thus identify subsets of pDCs with potent tolerogenic functions that may contribute to the maintenance of tolerance in mucosal sites such as the lungs. PMID:22472775

  16. Oxaliplatin regulates expression of stress ligands in ovarian cancer cells and modulates their susceptibility to natural killer cell-mediated cytotoxicity.

    PubMed

    Siew, Yin-Yin; Neo, Soek-Ying; Yew, Hui-Chuing; Lim, Shun-Wei; Ng, Yi-Cheng; Lew, Si-Min; Seetoh, Wei-Guang; Seow, See-Voon; Koh, Hwee-Ling

    2015-12-01

    Selected cytotoxic chemicals can provoke the immune system to recognize and destroy malignant tumors. Most of the studies on immunogenic cell death are focused on the signals that operate on a series of receptors expressed by dendritic cells to induce tumor antigen-specific T-cell responses. Here, we explored the effects of oxaliplatin, an immunogenic cell death inducer, on the induction of stress ligands and promotion of natural killer (NK) cell-mediated cytotoxicity in human ovarian cancer cells. The results indicated that treatment of tumor cells with oxaliplatin induced the production of type I interferons and chemokines and enhanced the expression of major histocompatibility complex class I-related chains (MIC) A/B, UL16-binding protein (ULBP)-3, CD155 and TNF-related apoptosis-inducing ligand (TRAIL)-R1/R2. Furthermore, oxaliplatin but not cisplatin treatment enhanced susceptibility of ovarian cancer cells to NK cell-mediated cytolysis. In addition, activated NK cells completely abrogated the growth of cancer cells that were pretreated with oxaliplatin. However, cancer cells pretreated with the same concentration of oxaliplatin alone were capable of potentiating regrowth over a period of time. These results suggest an advantage in combining oxaliplatin and NK cell-based therapy in the treatment of ovarian cancer. Further investigation on such potential combination therapy is warranted.

  17. The Vaccine Adjuvant Chitosan Promotes Cellular Immunity via DNA Sensor cGAS-STING-Dependent Induction of Type I Interferons.

    PubMed

    Carroll, Elizabeth C; Jin, Lei; Mori, Andres; Muñoz-Wolf, Natalia; Oleszycka, Ewa; Moran, Hannah B T; Mansouri, Samira; McEntee, Craig P; Lambe, Eimear; Agger, Else Marie; Andersen, Peter; Cunningham, Colm; Hertzog, Paul; Fitzgerald, Katherine A; Bowie, Andrew G; Lavelle, Ed C

    2016-03-15

    The cationic polysaccharide chitosan is an attractive candidate adjuvant capable of driving potent cell-mediated immunity, but the mechanism by which it acts is not clear. We show that chitosan promotes dendritic cell maturation by inducing type I interferons (IFNs) and enhances antigen-specific T helper 1 (Th1) responses in a type I IFN receptor-dependent manner. The induction of type I IFNs, IFN-stimulated genes and dendritic cell maturation by chitosan required the cytoplasmic DNA sensor cGAS and STING, implicating this pathway in dendritic cell activation. Additionally, this process was dependent on mitochondrial reactive oxygen species and the presence of cytoplasmic DNA. Chitosan-mediated enhancement of antigen specific Th1 and immunoglobulin G2c responses following vaccination was dependent on both cGAS and STING. These findings demonstrate that a cationic polymer can engage the STING-cGAS pathway to trigger innate and adaptive immune responses.

  18. Identification of GLA/SE as an effective adjuvant for the induction of robust humoral and cell-mediated immune responses to EBV-gp350 in mice and rabbits.

    PubMed

    Heeke, Darren S; Lin, Rui; Rao, Eileen; Woo, Jennifer C; McCarthy, Michael P; Marshall, Jason D

    2016-05-17

    Childhood infection with Epstein-Barr virus (EBV) is often asymptomatic and may result in mild flu-like symptoms, but exposure during adolescence and young adulthood can lead to acute infectious mononucleosis (AIM) with a pathology characterized by swollen lymph nodes, sore throat, and severe fatigue lasting weeks or months. A vaccine targeting the envelope glycoprotein gp350 adjuvanted with aluminum hydroxide complexed with the TLR4 agonist monophosphoryl lipid A (MPLA) achieved a 78% reduction in AIM incidence in a small phase II trial of college-age individuals, but development of this vaccine was halted by the manufacturer. Here, we report the evaluation in mice and rabbits of an EBV-gp350 vaccine combined with an adjuvant composed of the synthetic TLR4 agonist glucopyranosyl lipid A (GLA) integrated into stable emulsion (SE). In mice, GLA/SE-adjuvanted gp350 generated high IgG titers (both IgG1 and IgG2a/c subtypes), elevated EBV-neutralizing antibody titers, and robust poly-functional anti-gp350 CD4(+) T cell responses. In addition, GLA/SE routinely demonstrated superior performance over aluminum hydroxide in all immunological readouts, including induction of durable neutralizing antibody titers out to at least 1 year post-vaccination. Both components of the GLA/SE adjuvant were found to be required to get optimal responses in both arms of the immune response: specifically, SE for neutralizing antibodies and GLA for induction of T cell responses. Furthermore, this vaccine also elicited high neutralizing antibody titers in a second species, rabbit. These promising results suggest that clinical development of a vaccine comprised of EBV-gp350 plus GLA/SE has the potential to prevent AIM in post-adolescents.

  19. CCN Family 2/Connective Tissue Growth Factor (CCN2/CTGF) Promotes Osteoclastogenesis via Induction of and Interaction with Dendritic Cell–Specific Transmembrane Protein (DC-STAMP)

    PubMed Central

    Nishida, Takashi; Emura, Kenji; Kubota, Satoshi; Lyons, Karen M; Takigawa, Masaharu

    2013-01-01

    CCN family 2/connective tissue growth factor (CCN2/CTGF) promotes endochondral ossification. However, the role of CCN2 in the replacement of hypertrophic cartilage with bone is still unclear. The phenotype of Ccn2 null mice, having an expanded hypertrophic zone, indicates that the resorption of the cartilage extracellular matrix is impaired therein. Therefore, we analyzed the role of CCN2 in osteoclastogenesis because cartilage extracellular matrix is resorbed mainly by osteoclasts during endochondral ossification. Expression of the Ccn2 gene was upregulated in mouse macrophage cell line RAW264.7 on day 6 after treatment of glutathione S transferase (GST) fusion mouse receptor activator of NF-κB ligand (GST-RANKL), and a combination of recombinant CCN2 (rCCN2) and GST-RANKL significantly enhanced tartrate-resistant acid phosphatase (TRACP)–positive multinucleated cell formation compared with GST-RANKL alone. Therefore, we suspected the involvement of CCN2 in cell-cell fusion during osteoclastogenesis. To clarify the mechanism, we performed real-time PCR analysis of gene expression, coimmunoprecipitation analysis, and solid-phase binding assay of CCN2 and dendritic cell–specific transmembrane protein (DC-STAMP), which is involved in cell-cell fusion. The results showed that CCN2 induced and interacted with DC-STAMP. Furthermore, GST-RANKL–induced osteoclastogenesis was impaired in fetal liver cells from Ccn2 null mice, and the impaired osteoclast formation was rescued by the addition of exogenous rCCN2 or the forced expression of DC-STAMP by a retroviral vector. These results suggest that CCN2 expressed during osteoclastogenesis promotes osteoclast formation via induction of and interaction with DC-STAMP. PMID:20721934

  20. A novel dendritic cell-based immunization approach for the induction of durable Th1-polarized anti-HER-2/neu responses in women with early breast cancer.

    PubMed

    Koski, Gary K; Koldovsky, Ursula; Xu, Shuwen; Mick, Rosemarie; Sharma, Anupama; Fitzpatrick, Elizabeth; Weinstein, Susan; Nisenbaum, Harvey; Levine, Bruce L; Fox, Kevin; Zhang, Paul; Czerniecki, Brian J

    2012-01-01

    Twenty-seven patients with HER-2/neu overexpressing ductal carcinoma in situ of the breast were enrolled in a neoadjuvant immunization trial for safety and immunogenicity of DC1-polarized dendritic cells (DC1) pulsed with 6 HER-2/neu promiscuous major histocompatibility complex class II-binding peptides and 2 additional human leukocyte antigen (HLA)-A2.1 class I-binding peptides. DC1 were generated with interferon-γ and a special clinical-grade bacterial endotoxin (lipopolysaccharide) and administered directly into groin lymph nodes 4 times at weekly intervals before scheduled surgical resection of ductal carcinoma in situ. Patients were monitored for the induction of new or enhanced antipeptide reactivity by interferon-γ ELISPOT and enzyme-linked immunosorbentassays performed on Th cells obtained from peripheral blood or excised sentinel lymph nodes. Responses by cytotoxic T lymphocyte against HLA-A2.1-binding peptides were measured using peptide-pulsed T2 target cells or HER-2/neu-expressing or nonexpressing tumor cell lines. DC1 showed surface phenotype indistinct from "gold standard" inflammatory cocktail-activated DC, but displayed a number of distinguishing functional characteristics including the secretion of soluble factors and enhanced "killer DC" capacity against tumor cells in vitro. Postimmunization, we observed sensitization of Th cells to at least 1 class II peptide in 22 of 25 (88%; 95% exact confidence interval, 68.8%-97.5%) evaluable patients, whereas 11 of 13 (84.6%; 95% exact confidence interval, 64%-99.8%) HLA-A2.1 patients were successfully sensitized to class I peptides. Perhaps most importantly, anti-HER-2/neu peptide responses were observed up to 52-month postimmunization. These data show that even in the presence of early breast cancer such DC1 are potent inducers of durable type I-polarized immunity, suggesting potential clinical value for development of cancer immunotherapy.

  1. Anti-prostate cancer effects of CTL cell induction in vitro by recombinant adenovirus mediated PSMA/4-1BBL dendritic cells: an immunotherapy study.

    PubMed

    Sui, C-G; Wu, D; Meng, F-D; Yang, M-H; Jiang, Y-H

    2015-06-29

    This study aimed to examine anti-prostate cancer immune response induced by dendritic cells (DCs) transduced with PSMA/4-1BBL recombinant adenoviruses in vitro. Ad-PSMA, Ad-4-1BBL, and Ad-GFP were transfected into DCs derived from peripheral blood of healthy volunteers. Ad-PSMA/4-1BBL-DC, Ad-PSMA-DC, Ad-4-1BBL-DC, Ad-GFP-DC, and normal-DC, PSMA and 4-1BBL protein levels in DCs were detected by western blot. IL-12, IFN-γ and IL-10 were measured by ELISA. Mixed lymphocyte reaction and the cytotoxicity of each group targeted to LNCap, Du145, and 22RV prostate cancer cells were determined by CCK-8 assay. PSMA and 4-1BBL protein could express on DC successfully, the IL-12 supernatant content (134.29 ± 2.22 pg) was higher than others (P < 0.05). The ability to stimulate autologous T lymphocyte proliferation in the co-transfection group was higher than others (P < 0.05). When the DCs were co-cultured with CTLs, the PSMA/4-1BBL-DC-CTL group showed the highest content of IFN-γ (1176.10 ± 14.37pg/5 x 10(6) cells), but the lowest IL-10 content (75.14 ± 2.01 pg/5 x 10(6) cells) (P < 0.05), and the strongest anti-tumor effect when the effector to target ratio was 40:1, along with a higher killing ratio of LNCap cells than others (P < 0.05). Overall, Mature DCs transfected with Ad-PSMA/4- 1BBL not only showed high secretion of IL-12, but also induced CTLs to stimulate and enhance the killing effect of PSMA specific effector cells to PSMA positively expressing prostate cancer cells. Furthermore, the DCs infected with two kinds of tumor-associated antigens would induce more effective tumor-specific CTL induction.

  2. In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination.

    PubMed

    Bonifaz, Laura C; Bonnyay, David P; Charalambous, Anna; Darguste, Dara I; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K; Moltedo, Bruno; Moran, Thomas M; Steinman, Ralph M

    2004-03-15

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic alpha-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the alphaDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell-mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models.

  3. IL-6 and IL-10 induction from dendritic cells in response to Mycobacterium tuberculosis is predominantly dependent on TLR2-mediated recognition.

    PubMed

    Jang, Sihyug; Uematsu, Satoshi; Akira, Shizuo; Salgame, Padmini

    2004-09-01

    The initial TLR-mediated interaction between Mycobacterium tuberculosis and dendritic cells is critical, since the cytokine production that ensues can greatly influence the class of adaptive immunity that is generated to the pathogen. In this study, we therefore determined the dependency on TLR2 and TLR4 for M. tuberculosis-induced cytokine production by murine dendritic cells. A key new finding of this study is that production of IL-6 and IL-10 from dendritic cells in response to M. tuberculosis is principally dependent on TLR2. The study also indicates that M. tuberculosis can induce IL-12 production in the absence of either TLR2 or TLR4, suggesting redundancy or possibly involvement of other receptors in IL-12 production. In addition, the data also reveal that lack of TLR2 or TLR4 does not impact on dendritic cell maturation or on their ability to influence the polarity of differentiating naive T cells. Collectively, data presented here provide a mechanistic insight for the contribution of TLR2 and TLR4 to tuberculosis disease progression and offer strategies for regulating IL-6 and IL-10 production in dendritic cell-based vaccine strategies.

  4. Saponin-based adjuvants induce cross-presentation in dendritic cells by intracellular lipid body formation

    PubMed Central

    den Brok, Martijn H.; Büll, Christian; Wassink, Melissa; de Graaf, Annemarie M.; Wagenaars, Jori A.; Minderman, Marthe; Thakur, Mayank; Amigorena, Sebastian; Rijke, Eric O.; Schrier, Carla C.; Adema, Gosse J.

    2016-01-01

    Saponin-based adjuvants (SBAs) are being used in animal and human (cancer) vaccines, as they induce protective cellular immunity. Their adjuvant potency is a factor of inflammasome activation and enhanced antigen cross-presentation by dendritic cells (DCs), but how antigen cross-presentation is induced is not clear. Here we show that SBAs uniquely induce intracellular lipid bodies (LBs) in the CD11b+ DC subset in vitro and in vivo. Using genetic and pharmacological interference in models for vaccination and in situ tumour ablation, we demonstrate that LB induction is causally related to the saponin-dependent increase in cross-presentation and T-cell activation. These findings link adjuvant activity to LB formation, aid the application of SBAs as a cancer vaccine component, and will stimulate development of new adjuvants enhancing T-cell-mediated immunity. PMID:27819292

  5. Ageing and cell-mediated immunity.

    PubMed

    Fixa, B; Komárková, O; Chmelar, V

    1975-01-01

    The lymphocyte transformation test with phytohemagglutinin as mitogen estimated according to the incorporation of 2-(14)C-thymidine in DNA was used as an indicator of cell-mediated reactivity in 53 healthy subjects. Three age groups were examined: up to 20 years (21 subjects), 21-40 years (10 subjects) and over 70 years (22 subjects). The responsiveness of lymphocytes decreased significantly with age. In the highest age group 12 pathologically low values were found.

  6. [Production of a dialysable transfer factor of cell mediated immunity by lymphoblastoid cells in continuous proliferation].

    PubMed

    Goust, J M; Viza, D; Moulias, R; Trejdosiewicz, L; Lesourd, B; Marescot, M R; Prévot, A

    1975-01-20

    Four lymphoblastoid cell lines tested in this work contain normally a dialysable moiety having by ultraviolet spectroscopy, column chromatography (Biogel P 10) and chemically the same properties than human dialysable Transfer Factor (TFd), but unable to transfer cell mediated immune response against common antigens. Two of them are able to do so after incubation with minimal amounts of TFd. Production of a molecule identical to human TFd is possible in some lymphoblastoid cell lines after induction with TFd.

  7. Excitatory synapses on dendritic shafts of the caudal basal amygdala exhibit elevated levels of GABAA receptor α4 subunits following the induction of activity-based anorexia.

    PubMed

    Wable, Gauri S; Barbarich-Marsteller, Nicole C; Chowdhury, Tara G; Sabaliauskas, Nicole A; Farb, Claudia R; Aoki, Chiye

    2014-01-01

    Anorexia nervosa (AN) is an eating disorder characterized by self-imposed severe starvation, excessive exercise, and anxiety. The onset of AN is most often at puberty, suggesting that gonadal hormonal fluctuations may contribute to AN vulnerability. Activity-based anorexia (ABA) is an animal model that reproduces some of the behavioral phenotypes of AN, including the paradoxical increase in voluntary exercise following food restriction. The basal amygdala as well as the GABAergic system regulate trait anxiety. We therefore examined the subcellular distribution of GABA receptors (GABARs) in the basal amygdala of female pubertal rats and specifically of their α4 subunits, because expression of α4-containing GABARs is regulated by gonadal hormone fluctuations. Moreover, because these GABARs reduce neuronal excitability through shunting of EPSPs, we quantified the frequency of occurrence of these GABARs adjacent to excitatory synapses. Electron microscopic immunoctychemistry revealed no change in the frequency of association of α4 subunits with excitatory synapses on dendritic spines, whether in the anterior (Bregma -2.8 mm) or caudal (Bregma -3.8 mm) portion of the basal amygdala. Sholl analysis of golgi-stained neurons also revealed no change in the extent of dendritic branching by these densely spiny, pyramidal-like neurons. However, there was an increase of membranous α4 subunits near excitatory synapses on dendritic shafts, specifically in the caudal basal amygdala, and this was accompanied by a rise of α4 subunits intracellularly. Because most dendritic shafts exhibiting excitatory synapses are GABAergic interneurons, the results predict disinhibition, which would increase excitability of the amygdaloid network, in turn augmenting ABA animals' anxiety.

  8. Active dendrites, potassium channels and synaptic plasticity.

    PubMed Central

    Johnston, Daniel; Christie, Brian R; Frick, Andreas; Gray, Richard; Hoffman, Dax A; Schexnayder, Lalania K; Watanabe, Shigeo; Yuan, Li-Lian

    2003-01-01

    The dendrites of CA1 pyramidal neurons in the hippocampus express numerous types of voltage-gated ion channel, but the distributions or densities of many of these channels are very non-uniform. Sodium channels in the dendrites are responsible for action potential (AP) propagation from the axon into the dendrites (back-propagation); calcium channels are responsible for local changes in dendritic calcium concentrations following back-propagating APs and synaptic potentials; and potassium channels help regulate overall dendritic excitability. Several lines of evidence are presented here to suggest that back-propagating APs, when coincident with excitatory synaptic input, can lead to the induction of either long-term depression (LTD) or long-term potentiation (LTP). The induction of LTD or LTP is correlated with the magnitude of the rise in intracellular calcium. When brief bursts of synaptic potentials are paired with postsynaptic APs in a theta-burst pairing paradigm, the induction of LTP is dependent on the invasion of the AP into the dendritic tree. The amplitude of the AP in the dendrites is dependent, in part, on the activity of a transient, A-type potassium channel that is expressed at high density in the dendrites and correlates with the induction of the LTP. Furthermore, during the expression phase of the LTP, there are local changes in dendritic excitability that may result from modulation of the functioning of this transient potassium channel. The results support the view that the active properties of dendrites play important roles in synaptic integration and synaptic plasticity of these neurons. PMID:12740112

  9. Induction of strong and persistent MelanA/MART-1-specific immune responses by adjuvant dendritic cell-based vaccination of stage II melanoma patients.

    PubMed

    Tuettenberg, Andrea; Becker, Christian; Huter, Eva; Knop, Jürgen; Enk, Alexander H; Jonuleit, Helmut

    2006-05-15

    A significant percentage of stage II melanoma patients (tumor thickness>1 mm) remain at risk of tumor recurrence after primary tumor excision. In this study, we used tumor antigen-pulsed dendritic cells as an adjuvant for immunization of these "high-risk" melanoma patients after resection of the primary tumor. A total of 13 patients were included and vaccinated 6 times every 14 days with autologous dendritic cells pulsed with a MelanA/MART-1 peptide in combination with a recall antigen. Antigen-specific immune responses were monitored before, during and up to 1 year after the last vaccination. The majority of patients exhibited increased recall antigen-specific CD4+ T cell responses upon vaccination. MelanA/MART-1-specific CD8+ T cells were expanded in 9/13 patients resulting in increased frequencies of memory cells in these patients. CD8+ T cells acquired the capacity to secrete IFN-gamma, to proliferate in culture in response to the tumor antigen used for vaccination and postvaccine samples contained MelanA/MART-1-specific T cells that recognized also the natural MelanA/MART-1-antigen expressed by tumor cells. Moreover, vaccination induced a long-lived tumor antigen-specific DTH-reactivity in the majority of the patients, detectable even 12 months after the last immunization. These data demonstrate for the first time that vaccination with tumor antigen-pulsed dendritic cells in a clinically adjuvant setting induces strong and persistent antigen-specific T-cell responses in tumor-free stage II melanoma patients, suggesting that tumor protective T cell immunity can be achieved.

  10. Electric Pulse Stimulation of Myotubes as an In Vitro Exercise Model: Cell-Mediated and Non-Cell-Mediated Effects.

    PubMed

    Evers-van Gogh, Inkie J A; Alex, Sheril; Stienstra, Rinke; Brenkman, Arjan B; Kersten, Sander; Kalkhoven, Eric

    2015-06-19

    Regular exercise has emerged as one of the best therapeutic strategies to prevent and treat type-2-diabetes. Exercise-induced changes in the muscle secretome, consisting of myokines and metabolites, may underlie the inter-organ communication between muscle and other organs. To investigate this crosstalk, we developed an in vitro system in which mouse C2C12 myotubes underwent electric pulse stimulation (EPS) to induce contraction. Subsequently the effects of EPS-conditioned media (EPS-CM) on hepatocytes were investigated. Here, we demonstrate that EPS-CM induces Metallothionein 1/2 and Slc30a2 gene expression and reduces Cyp2a3 gene expression in rat hepatocytes. When testing EPS-CM that was generated in the absence of C2C12 myotubes (non-cell EPS-CM) no decrease in Cyp2a3 expression was detected. However, similar inductions in hepatic Mt1/2 and Slc30a2 expression were observed. Non-cell EPS-CM were also applied to C2C12 myotubes and compared to C2C12 myotubes that underwent EPS: here changes in AMPK phosphorylation and myokine secretion largely depended on EPS-induced contraction. Taken together, these findings indicate that EPS can alter C2C12 myotube function and thereby affect gene expression in cells subjected to EPS-CM (Cyp2a3). However, EPS can also generate non-cell-mediated changes in cell culture media, which can affect gene expression in cells subjected to EPS-CM too. While EPS clearly represents a valuable tool in exercise research, care should be taken in experimental design to control for non-cell-mediated effects.

  11. Electric Pulse Stimulation of Myotubes as an In Vitro Exercise Model: Cell-Mediated and Non-Cell-Mediated Effects

    PubMed Central

    Evers-van Gogh, Inkie J.A.; Alex, Sheril; Stienstra, Rinke; Brenkman, Arjan B.; Kersten, Sander; Kalkhoven, Eric

    2015-01-01

    Regular exercise has emerged as one of the best therapeutic strategies to prevent and treat type-2-diabetes. Exercise-induced changes in the muscle secretome, consisting of myokines and metabolites, may underlie the inter-organ communication between muscle and other organs. To investigate this crosstalk, we developed an in vitro system in which mouse C2C12 myotubes underwent electric pulse stimulation (EPS) to induce contraction. Subsequently the effects of EPS-conditioned media (EPS-CM) on hepatocytes were investigated. Here, we demonstrate that EPS-CM induces Metallothionein 1/2 and Slc30a2 gene expression and reduces Cyp2a3 gene expression in rat hepatocytes. When testing EPS-CM that was generated in the absence of C2C12 myotubes (non-cell EPS-CM) no decrease in Cyp2a3 expression was detected. However, similar inductions in hepatic Mt1/2 and Slc30a2 expression were observed. Non-cell EPS-CM were also applied to C2C12 myotubes and compared to C2C12 myotubes that underwent EPS: here changes in AMPK phosphorylation and myokine secretion largely depended on EPS-induced contraction. Taken together, these findings indicate that EPS can alter C2C12 myotube function and thereby affect gene expression in cells subjected to EPS-CM (Cyp2a3). However, EPS can also generate non-cell-mediated changes in cell culture media, which can affect gene expression in cells subjected to EPS-CM too. While EPS clearly represents a valuable tool in exercise research, care should be taken in experimental design to control for non-cell-mediated effects. PMID:26091097

  12. The CD8+ T Cell-Mediated Immunity Induced by HPV-E6 Uploaded in Engineered Exosomes Is Improved by ISCOMATRIXTM Adjuvant

    PubMed Central

    Manfredi, Francesco; di Bonito, Paola; Ridolfi, Barbara; Anticoli, Simona; Arenaccio, Claudia; Chiozzini, Chiara; Baz Morelli, Adriana; Federico, Maurizio

    2016-01-01

    We recently described the induction of an efficient CD8+ T cell-mediated immune response against a tumor-associated antigen (TAA) uploaded in engineered exosomes used as an immunogen delivery tool. This immune response cleared tumor cells inoculated after immunization, and controlled the growth of tumors implanted before immunization. We looked for new protocols aimed at increasing the CD8+ T cell specific response to the antigen uploaded in engineered exosomes, assuming that an optimized CD8+ T cell immune response would correlate with a more effective depletion of tumor cells in the therapeutic setting. By considering HPV-E6 as a model of TAA, we found that the in vitro co-administration of engineered exosomes and ISCOMATRIXTM adjuvant, i.e., an adjuvant composed of purified ISCOPREPTM saponin, cholesterol, and phospholipids, led to a stronger antigen cross-presentation in both B- lymphoblastoid cell lines ( and monocyte-derived immature dendritic cells compared with that induced by the exosomes alone. Consistently, the co-inoculation in mice of ISCOMATRIXTM adjuvant and engineered exosomes induced a significant increase of TAA-specific CD8+ T cells compared to mice immunized with the exosomes alone. This result holds promise for effective usage of exosomes as well as alternative nanovesicles in anti-tumor therapeutic approaches. PMID:27834857

  13. Plasmacytoid dendritic cells in autoimmune diabetes - potential tools for immunotherapy.

    PubMed

    Nikolic, Tatjana; Welzen-Coppens, Jojanneke M C; Leenen, Pieter J M; Drexhage, Hemmo A; Versnel, Marjan A

    2009-01-01

    Type 1 diabetes (T1D) is an autoimmune disease in which a T-cell-mediated attack destroys the insulin-producing cells of the pancreatic islets. Despite insulin supplementation severe complications ask for novel treatments that aim at cure or delay of the onset of the disease. In spontaneous animal models for diabetes like the nonobese diabetic (NOD) mouse, distinct steps in the pathogenesis of the disease can be distinguished. In the past 10 years it became evident that DC and macrophages play an important role in all three phases of the pathogenesis of T1D. In phase 1, dendritic cells (DC) and macrophages accumulate at the islet edges. In phase 2, DC and macrophages are involved in the activation of autoreactive T cells that accumulate in the pancreas. In the third phase the islets are invaded by macrophages, DC and NK cells followed by the destruction of the beta-cells. Recent data suggest a role for a new member of the DC family: the plasmacytoid DC (pDC). pDC have been found to induce tolerance in experimental models of asthma. Several studies in humans and the NOD mouse support a similar role for pDC in diabetes. Mechanisms found to be involved in tolerance induction by pDC are inhibition of effector T cells, induction of regulatory T cells, production of cytokines and indoleamine 2,3-dioxygenase (IDO). The exact mechanism of tolerance induction by pDC in diabetes remains to be established but the intrinsic tolerogenic properties of pDC provide a promising, yet underestimated target for therapeutic intervention.

  14. Dendritic Cells in Innate and Adaptive Immune Responses against Influenza Virus

    PubMed Central

    Summerfield, Artur; McCullough, Kenneth C.

    2009-01-01

    Dendritic cells (DC) are major players in both innate and adaptive immune responses against influenza virus. These immune responses, as well as the important interface between the innate and adaptive systems, are orchestrated by specialized subsets of DC, including conventional steady-state DC, migratory DC and plasmacytoid DC. The characteristics and efficacy of the responses are dependent on the relative activity of these DC subsets, rendering DC crucial for the development of both naïve and memory immune responses. However, due to their critical role, DC also contribute to the immunopathological processes observed during acute influenza, such as that caused by the pathogenic H5N1 viruses. Therein, the role of different DC subsets in the induction of interferon type I, pro-inflammatory cytokine and chemokine responses is important for the outcome of interaction between the virus and host immune defences. The present review will present current knowledge on this area, relating to the importance of DC activity for the induction of efficacious humoral and cell-mediated immune responses. This will include the main viral elements associated with the triggering or inhibition of DC activation. Finally, the current knowledge on understanding how differences in various vaccines influence the manner of immune defence induction will be presented. PMID:21994580

  15. Dendrite inhibitor

    DOEpatents

    Miller, William E.

    1989-01-01

    An apparatus for removing dendrites or other crystalline matter from the surface of a liquid in a matter transport process, and an electrolytic cell including such an apparatus. A notch may be provided to allow continuous exposure of the liquid surface, and a bore may be further provided to permit access to the liquid.

  16. Dendrite inhibitor

    DOEpatents

    Miller, W.E.

    1988-06-07

    An apparatus for removing dendrites or other crystalline matter from the surface of a liquid in a matter transport process, and an electrolytic cell including such an apparatus. A notch may be provided to allow continuous exposure of the liquid surface, and a bore may be further provided to permit access to the liquid. 2 figs.

  17. Invariant NKT cells induce plasmacytoid dendritic cell (DC) cross-talk with conventional DCs for efficient memory CD8+ T cell induction.

    PubMed

    Shimizu, Kanako; Asakura, Miki; Shinga, Jun; Sato, Yusuke; Kitahara, Shuji; Hoshino, Katsuaki; Kaisho, Tsuneyasu; Schoenberger, Stephen P; Ezaki, Taichi; Fujii, Shin-ichiro

    2013-06-01

    A key goal of vaccine immunotherapy is the generation of long-term memory CD8(+) T cells capable of mediating immune surveillance. We discovered a novel intercellular pathway governing the development of potent memory CD8(+) T cell responses against cell-associated Ags that is mediated through cross-presentation by XCR1(+) dendritic cells (DCs). Generation of CD8(+) memory T cells against tumor cells pulsed with an invariant NKT cell ligand depended on cross-talk between XCR1(+) and plasmacytoid DCs that was regulated by IFN-α/IFN-αR signals. IFN-α production by plasmacytoid DCs was stimulated by an OX40 signal from the invariant NKT cells, as well as an HMGB1 signal from the dying tumor cells. These findings reveal a previously unknown pathway of intercellular collaboration for the generation of tumor-specific CD8(+) memory T cells that can be exploited for strategic vaccination in the setting of tumor immunotherapy.

  18. Uptake of synthetic naked RNA by skin-resident dendritic cells via macropinocytosis allows antigen expression and induction of T-cell responses in mice.

    PubMed

    Selmi, Abderraouf; Vascotto, Fulvia; Kautz-Neu, Kordula; Türeci, Özlem; Sahin, Ugur; von Stebut, Esther; Diken, Mustafa; Kreiter, Sebastian

    2016-09-01

    Intradermal administration of antigen-encoding RNA has entered clinical testing for cancer vaccination. However, insight into the underlying mechanism of RNA uptake, translation and antigen presentation is still limited. Utilizing pharmacologically optimized naked RNA, the dose-response kinetics revealed a rise in reporter signal with increasing RNA amounts and a prolonged RNA translation of reporter protein up to 30 days after intradermal injection. Dendritic cells (DCs) in the dermis were shown to engulf RNA, and the signal arising from the reporter RNA was significantly diminished after DC depletion. Macropinocytosis was relevant for intradermal RNA uptake and translation in vitro and in vivo. By combining intradermal RNA vaccination and inhibition of macropinocytosis, we show that effective priming of antigen-specific CD8(+) T-cells also relies on this uptake mechanism. This report demonstrates that direct antigen translation by dermal DCs after intradermal naked RNA vaccination is relevant for efficient priming of antigen-specific T-cells.

  19. Mast Cell-Mediated Mechanisms of Nociception.

    PubMed

    Aich, Anupam; Afrin, Lawrence B; Gupta, Kalpna

    2015-12-04

    Mast cells are tissue-resident immune cells that release immuno-modulators, chemo-attractants, vasoactive compounds, neuropeptides and growth factors in response to allergens and pathogens constituting a first line of host defense. The neuroimmune interface of immune cells modulating synaptic responses has been of increasing interest, and mast cells have been proposed as key players in orchestrating inflammation-associated pain pathobiology due to their proximity to both vasculature and nerve fibers. Molecular underpinnings of mast cell-mediated pain can be disease-specific. Understanding such mechanisms is critical for developing disease-specific targeted therapeutics to improve analgesic outcomes. We review molecular mechanisms that may contribute to nociception in a disease-specific manner.

  20. Mast Cell-Mediated Mechanisms of Nociception

    PubMed Central

    Aich, Anupam; Afrin, Lawrence B.; Gupta, Kalpna

    2015-01-01

    Mast cells are tissue-resident immune cells that release immuno-modulators, chemo-attractants, vasoactive compounds, neuropeptides and growth factors in response to allergens and pathogens constituting a first line of host defense. The neuroimmune interface of immune cells modulating synaptic responses has been of increasing interest, and mast cells have been proposed as key players in orchestrating inflammation-associated pain pathobiology due to their proximity to both vasculature and nerve fibers. Molecular underpinnings of mast cell-mediated pain can be disease-specific. Understanding such mechanisms is critical for developing disease-specific targeted therapeutics to improve analgesic outcomes. We review molecular mechanisms that may contribute to nociception in a disease-specific manner. PMID:26690128

  1. Protein Kinase M[Zeta] Is Essential for the Induction and Maintenance of Dopamine-Induced Long-Term Potentiation in Apical CA1 Dendrites

    ERIC Educational Resources Information Center

    Navakkode, Sheeja; Sajikumar, Sreedharan; Sacktor, Todd Charlton; Frey, Julietta U.

    2010-01-01

    Dopaminergic D1/D5-receptor-mediated processes are important for certain forms of memory as well as for a cellular model of memory, hippocampal long-term potentiation (LTP) in the CA1 region of the hippocampus. D1/D5-receptor function is required for the induction of the protein synthesis-dependent maintenance of CA1-LTP (L-LTP) through activation…

  2. The role of dendritic action potentials and Ca2+ influx in the induction of homosynaptic long-term depression in hippocampal CA1 pyramidal neurons.

    PubMed

    Christie, B R; Magee, J C; Johnston, D

    1996-01-01

    Long-term depression (LTD) of synaptic efficacy at CA1 synapses is believed to be a Ca(2+)-dependent process. We used high-speed fluorescence imaging and patch-clamp techniques to quantify the spatial distribution of changes in intracellular Ca2+ accompanying the induction of LTD at Schaffer collateral synapses in CA1 pyramidal neurons. Low-frequency stimulation (3 Hz), which was subthreshold for action potentials, produced small changes in [Ca2+]i and failed to elicit LTD. Increasing the stimulus strength so that action potentials were generated produced both robust LTD and increases in [Ca2+]i. Back-propagating action potentials at 3 Hz in the absence of synaptic stimulation also produced increases in [Ca2+]i, but failed to induce LTD. When subthreshold synaptic stimulation was paired with back-propagating action potentials, however, large increases in [Ca2+]i were observed and robust LTD was induced. The LTD was blocked by the N-methyl-D-aspartate receptor (NMDAr) antagonist APV, and stimulus-induced increases in [Ca2+]i were reduced throughout the neuron under these conditions. The LTD was also dependent on Ca2+ influx via voltage-gated Ca2+ channels (VGCCs), because LTD was severely attenuated or blocked by both nimodipine and Ni2+. These findings suggest that back-propagating action potentials can exert a powerful control over the induction of LTD and that both VGCCs and NMDArs are involved in the induction of this form of plasticity.

  3. The presence of T cell epitopes is important for induction of antibody responses against antigens directed to DEC205+ dendritic cells

    PubMed Central

    Amorim, Kelly N. S.; Rampazo, Eline V.; Antonialli, Renan; Yamamoto, Marcio M.; Rodrigues, Mauricio M.; Soares, Irene S.; Boscardin, Silvia B.

    2016-01-01

    In vivo antigen targeting to dendritic cells (DCs) has been used as a way to improve immune responses. Targeting is accomplished with the use of monoclonal antibodies (mAbs) to receptors present on the DC surface fused with the antigen of interest. An anti-DEC205 mAb has been successfully used to target antigens to the DEC205+CD8α+ DC subset. The administration of low doses of the hybrid mAb together with DC maturation stimuli is able to activate specific T cells and induce production of high antibody titres for a number of different antigens. However, it is still not known if this approach would work with any fused protein. Here we genetically fused the αDEC205 mAb with two fragments (42-kDa and 19-kDa) derived from the ~200 kDa Plasmodium vivax merozoite surface protein 1 (MSP1), known as MSP142 and MSP119, respectively. The administration of two doses of αDEC-MSP142, but not of αDEC-MSP119 mAb, together with an adjuvant to two mouse strains induced high anti-MSP119 antibody titres that were dependent on CD4+ T cells elicited by peptides present in the MSP133 sequence, indicating that the presence of T cell epitopes in antigens targeted to DEC205+ DCs increases antibody responses. PMID:28000705

  4. A dominant role for the methyl-CpG-binding protein Mbd2 in controlling Th2 induction by dendritic cells

    PubMed Central

    Cook, Peter C.; Owen, Heather; Deaton, Aimée M.; Borger, Jessica G.; Brown, Sheila L.; Clouaire, Thomas; Jones, Gareth-Rhys; Jones, Lucy H.; Lundie, Rachel J.; Marley, Angela K.; Morrison, Vicky L.; Phythian-Adams, Alexander T.; Wachter, Elisabeth; Webb, Lauren M.; Sutherland, Tara E.; Thomas, Graham D.; Grainger, John R.; Selfridge, Jim; McKenzie, Andrew N. J.; Allen, Judith E.; Fagerholm, Susanna C.; Maizels, Rick M.; Ivens, Alasdair C.; Bird, Adrian; MacDonald, Andrew S.

    2015-01-01

    Dendritic cells (DCs) direct CD4+ T-cell differentiation into diverse helper (Th) subsets that are required for protection against varied infections. However, the mechanisms used by DCs to promote Th2 responses, which are important both for immunity to helminth infection and in allergic disease, are currently poorly understood. We demonstrate a key role for the protein methyl-CpG-binding domain-2 (Mbd2), which links DNA methylation to repressive chromatin structure, in regulating expression of a range of genes that are associated with optimal DC activation and function. In the absence of Mbd2, DCs display reduced phenotypic activation and a markedly impaired capacity to initiate Th2 immunity against helminths or allergens. These data identify an epigenetic mechanism that is central to the activation of CD4+ T-cell responses by DCs, particularly in Th2 settings, and reveal methyl-CpG-binding proteins and the genes under their control as possible therapeutic targets for type-2 inflammation. PMID:25908537

  5. Influenza Virus–induced Dendritic Cell Maturation Is Associated with the Induction of Strong T Cell Immunity to a Coadministered, Normally Nonimmunogenic Protein

    PubMed Central

    Brimnes, Marie K.; Bonifaz, Laura; Steinman, Ralph M.; Moran, Thomas M.

    2003-01-01

    We evaluated the proposal that during microbial infection, dendritic cells (DCs) undergo maturation and present a mixture of peptides derived from the microbe as well as harmless environmental antigens. Mice were exposed to an aerosol of endotoxin free ovalbumin (OVA) in the absence or presence of influenza virus. In its absence, OVA failed to induce B and T cell responses and even tolerized, but with influenza, OVA-specific antibodies and CD8+ cytolytic T lymphocytes developed. With or without infection, OVA was presented selectively in the draining mediastinal lymph nodes, as assessed by the comparable proliferation of infused, CD8+ and CD4+, TCR transgenic T cells. In the absence of influenza, these OVA-specific T cells produced little IL-2, IL-4, IL-10, and IFN-γ, but with infection, both CD4+ and CD8+ T cells made high levels of IL-2 and IFN-γ. The OVA plus influenza-treated mice also showed accelerated recovery to a challenge with recombinant vaccinia OVA virus. CD11c+ DCs from the mediastinal lymph nodes of infected mice selectively stimulated both OVA- and influenza-specific T cells and underwent maturation, with higher levels of MHC class II, CD80, and CD86 molecules. The relatively slow (2–3 d) kinetics of maturation correlated closely to the time at which OVA inhalation elicited specific antibodies. Therefore respiratory infection can induce DC maturation and simultaneously B and T cell immunity to an innocuous antigen inhaled concurrently. PMID:12847140

  6. Induction of Th17 Lymphocytes and Treg Cells by Monocyte-Derived Dendritic Cells in Patients with Rheumatoid Arthritis and Systemic Lupus Erythematosus

    PubMed Central

    Estrada-Capetillo, Lizbeth; Hernández-Castro, Berenice; Monsiváis-Urenda, Adriana; Alvarez-Quiroga, Crisol; Layseca-Espinosa, Esther; Abud-Mendoza, Carlos; Baranda, Lourdes; Urzainqui, Ana; Sánchez-Madrid, Francisco; González-Amaro, Roberto

    2013-01-01

    Dendritic cells (DCs) have a key role in the regulation of immune response. We herein explored, in patients with inflammatory diseases, the role of monocyte derived DC's (mo-DCs) on the generation of Th17 and T regulatory (Treg) lymphocytes. Peripheral blood was obtained from thirty-five patients with rheumatoid arthritis (RA), twelve with systemic lupus erythematosus (SLE), and twenty healthy subjects. Mo-DCs were generated under standard (IL-4/GM-CSF) or tolerogenic (IL-4/GM-CSF plus recombinant P-selectin or PD-1 or IL-10) conditions, and their ability to induce Th17 and Treg lymphocytes was tested. We detected that mo-DCs from patients with RA showed an enhanced release of IL-6 and IL-23 as well as an increased capability to induce Th17 cells. Although mo-DCs from SLE patients also released high levels of IL-6/IL-23, it did not show an increased ability to induce Th17 lymphocytes. In addition, mo-DCs, from patients with RA and SLE generated under the engagement of PSGL-1, showed a defective capability to induce Foxp3+ Treg cells. A similar phenomenon was observed in SLE, when DC's cells were generated under PDL-1 engagement. Our data indicate that DCs from patients with rheumatic inflammatory disease show an aberrant function that may have an important role in the pathogenesis of these conditions. PMID:24288552

  7. Induction of CML28-specific cytotoxic T cell responses using co-transfected dendritic cells with CML28 DNA vaccine and SOCS1 small interfering RNA expression vector

    SciTech Connect

    Zhou Hongsheng; Zhang Donghua . E-mail: hanson2008@gmail.com; Wang Yaya; Dai Ming; Zhang Lu; Liu Wenli; Liu Dan; Tan Huo; Huang Zhenqian

    2006-08-18

    CML28 is an attractive target for antigen-specific immunotherapy. SOCS1 represents an inhibitory control mechanism for DC antigen presentation and the magnitude of adaptive immunity. In this study, we evaluated the potential for inducing CML28-specific cytotoxic T lymphocytes (CTL) responses by dendritic cells (DCs)-based vaccination. We constructed a CML28 DNA vaccine and a SOCS1 siRNA vector and then cotransfect monocyte-derived DCs. Flow cytometry analysis showed gene silencing of SOCS1 resulted in higher expressions of costimulative moleculars in DCs. Mixed lymphocyte reaction (MLR) indicated downregulation of SOCS1 stronger capability to stimulate proliferation of responder cell in DCs. The CTL assay revealed transfected DCs effectively induced autologous CML28-specific CTL responses and the lytic activities induced by SOCS1-silenced DCs were significantly higher compared with those induced by SOCS1-expressing DCs. These results in our study indicates gene silencing of SOCS1 remarkably enhanced the cytotoxicity efficiency of CML28 DNA vaccine in DCs.

  8. Co-transfection of dendritic cells with AFP and IL-2 genes enhances the induction of tumor antigen-specific antitumor immunity.

    PubMed

    Yang, Jing-Yue; Li, Xiao; Gao, Li; Teng, Zeng-Hui; Liu, Wen-Chao

    2012-10-01

    Dendritic cells (DCs) are highly efficient, specialized antigen-presenting cells and DCs transfected with tumor-related antigens are regarded as promising vaccines in cancer immunotherapy. The aim of the present study was to investigate whether DCs co-transfected with the α-fetoprotein (AFP) and human interleukin-2 (IL-2) genes were able to induce stronger therapeutic antitumor immunity in transfected DCs. In this study, DCs from hepatocellular carcinoma (HCC) patients were co-transfected with the IL-2 gene and/or the AFP gene. The reverse transcription-PCR (RT-PCR) data revealed that the DCs transfected with the adenovirus AdAFP/IL-2 expressed AFP and IL-2. The DCs co-transfected with IL-2 and AFP (AFP/IL-2-DCs) enhanced the cytotoxicities of cytotoxic T lymphocytes (CTLs) and increased the production of IL-2 and interferon-γ significantly compared with their AFP-DC, green fluorescent protein (GFP)-DC, DC or phosphate-buffered saline (PBS) counterparts. In vivo data suggested that immunization with AFP-DCs enhances antigen-specific antitumor efficacy more potently than immunization with IL-2-DCs or AFP-DCs. These findings provide a potential strategy to improve the efficacy of DC-based tumor vaccines.

  9. Induction of CD8+ cytotoxic T lymphocytes by immunization with syngeneic irradiated HIV-1 envelope derived peptide-pulsed dendritic cells.

    PubMed

    Takahashi, H; Nakagawa, Y; Yokomuro, K; Berzofsky, J A

    1993-08-01

    Based on the evidence that CD8+ cytotoxic T cells (CTL) precursors do not appear to distinguish between virus-infected cells and viral peptide-pulsed syngeneic cells, we have developed methods for priming class I MHC molecule restricted CD8+ CTL with such peptides without using any adjuvant. We were able to prime in vivo such CTL immunity lasting at least 6 months with a single i.v. injection of syngeneic 2200-3300 rad irradiated peptide-pulsed spleen cells, and even more efficiently with a very small number of irradiated class II MHC molecule expressing splenic dendritic cells (DC). No foreign serum source was necessary during the pulsing. Interestingly, we could not generate significant CTL activity with unirradiated or low dose (< 1100 rad) irradiated spleen cells. Because even purified DC required irradiation for optimal activity, because unirradiated B cells did not significantly inhibit the immunization with DC, and because B cell depletion did not substitute for irradiation, we believe that the effect of irradiation is more to determine homing of the cells than to eliminate interference by B cells. Intravenous immunization was much more effective than s.c. or i.p. immunization. CTL generated by this method could kill both peptide-pulsed syngeneic targets and targets endogenously expressing the whole gp160 gene. Moreover, we found that we could prime CD8+ CTL with the minimal 10-residue core peptide (RGPGRAFVTI) for optimal presentation by class I MHC molecules as efficiently as the original p18. These results suggested that DC bearing antigenic peptide may prime antigen-specific CD8+ CTL in vivo. These results offer useful information for development of synthetic peptide vaccines and immunotherapy.

  10. Resting Respiratory Tract Dendritic Cells Preferentially Stimulate T Helper Cell Type 2 (Th2) Responses and Require Obligatory Cytokine Signals for Induction of  Th1 Immunity

    PubMed Central

    Stumbles, Philip A.; Thomas, Jennifer A.; Pimm, Carolyn L.; Lee, Peter T.; Venaille, Thierry J.; Proksch, Stephen; Holt, Patrick G.

    1998-01-01

    Consistent with their role in host defense, mature dendritic cells (DCs) from central lymphoid organs preferentially prime for T helper cell type 1 (Th1)-polarized immunity. However, the “default” T helper response at mucosal surfaces demonstrates Th2 polarity, which is reflected in the cytokine profiles of activated T cells from mucosal lymph nodes. This study on rat respiratory tract DCs (RTDCs) provides an explanation for this paradox. We demonstrate that freshly isolated RTDCs are functionally immature as defined in vitro, being surface major histocompatibility complex (MHC) II lo, endocytosishi, and mixed lymphocyte reactionlo, and these cells produce mRNA encoding interleukin (IL)-10. After ovalbumin (OVA)-pulsing and adoptive transfer, freshly isolated RTDCs preferentially stimulated Th2-dependent OVA-specific immunoglobulin (Ig)G1 responses, and antigen-stimulated splenocytes from recipient animals produced IL-4 in vitro. However, preculture with granulocyte/macrophage colony stimulating factor increased their in vivo IgG priming capacity by 2–3 logs, inducing production of both Th1- and Th2-dependent IgG subclasses and high levels of IFN-γ by antigen-stimulated splenocytes. Associated phenotypic changes included upregulation of surface MHC II and B7 expression and IL-12 p35 mRNA, and downregulation of endocytosis, MHC II processing– associated genes, and IL-10 mRNA expression. Full expression of IL-12 p40 required additional signals, such as tumor necrosis factor α or CD40 ligand. These results suggest that the observed Th2 polarity of the resting mucosal immune system may be an inherent property of the resident DC population, and furthermore that mobilization of Th1 immunity relies absolutely on the provision of appropriate microenvironmental costimuli. PMID:9841916

  11. A novel and simple method for generation of human dendritic cells from unfractionated peripheral blood mononuclear cells within 2 days: its application for induction of HIV-1-reactive CD4(+) T cells in the hu-PBL SCID mice.

    PubMed

    Kodama, Akira; Tanaka, Reiko; Saito, Mineki; Ansari, Aftab A; Tanaka, Yuetsu

    2013-01-01

    Because dendritic cells (DCs) play a critical role in the regulation of adaptive immune responses, they have been ideal candidates for cell-based immunotherapy of cancers and infections in humans. Generally, monocyte-derived DCs (MDDCs) were generated from purified monocytes by multiple steps of time-consuming physical manipulations for an extended period cultivation. In this study, we developed a novel, simple and rapid method for the generation of type-1 helper T cell (Th1)-stimulating human DCs directly from bulk peripheral blood mononuclear cells (PBMCs). PBMCs were cultivated in the presence of 20 ng/ml of granulocyte-macrophage colony-stimulating factor, 20 ng/ml of interleukin-4 (IL-4) and 1,000 U/ml of interferon-β for 24 h followed by 24 h maturation with a cytokine cocktail containing 10 ng/ml of tumor necrosis factor-α (TNF-α), 10 ng/ml of IL-1β and 1 μg/ml of prostaglandin E2. The phenotype and biological activity of these new DCs for induction of allogeneic T cell proliferation and cytokine production were comparable to those of the MDDCs. Importantly, these new DCs pulsed with inactivated HIV-1 could generated HIV-1-reactive CD4(+) T cell responses in humanized mice reconstituted with autologous PBMCs from HIV-1-negative donors. This simple and quick method for generation of functional DCs will be useful for future studies on DC-mediated immunotherapies.

  12. Inflammatory dendritic cells—not basophils—are necessary and sufficient for induction of Th2 immunity to inhaled house dust mite allergen

    PubMed Central

    Plantinga, Maud; Deswarte, Kim; Pouliot, Philippe; Willart, Monique A.M.; Kool, Mirjam; Muskens, Femke

    2010-01-01

    It is unclear how Th2 immunity is induced in response to allergens like house dust mite (HDM). Here, we show that HDM inhalation leads to the TLR4/MyD88-dependent recruitment of IL-4 competent basophils and eosinophils, and of inflammatory DCs to the draining mediastinal nodes. Depletion of basophils only partially reduced Th2 immunity, and depletion of eosinophils had no effect on the Th2 response. Basophils did not take up inhaled antigen, present it to T cells, or express antigen presentation machinery, whereas a population of FceRI+ DCs readily did. Inflammatory DCs were necessary and sufficient for induction of Th2 immunity and features of asthma, whereas basophils were not required. We favor a model whereby DCs initiate and basophils amplify Th2 immunity to HDM allergen. PMID:20819925

  13. B-Cell-Mediated Strategies to Fight Chronic Allograft Rejection

    PubMed Central

    Dalloul, Ali

    2013-01-01

    Solid organs have been transplanted for decades. Since the improvement in graft selection and in medical and surgical procedures, the likelihood of graft function after 1 year is now close to 90%. Nonetheless even well-matched recipients continue to need medications for the rest of their lives hence adverse side effects and enhanced morbidity. Understanding Immune rejection mechanisms, is of increasing importance since the greater use of living-unrelated donors and genetically unmatched individuals. Chronic rejection is devoted to T-cells, however the role of B-cells in rejection has been appreciated recently by the observation that B-cell depletion improve graft survival. By contrast however, B-cells can be beneficial to the grafted tissue. This protective effect is secondary to either the secretion of protective antibodies or the induction of B-cells that restrain excessive inflammatory responses, chiefly by local provision of IL-10, or inhibit effector T-cells by direct cellular interactions. As a proof of concept B-cell-mediated infectious transplantation tolerance could be achieved in animal models, and evidence emerged that the presence of such B-cells in transplanted patients correlate with a favorable outcome. Among these populations, regulatory B-cells constitute a recently described population. These cells may develop as a feedback mechanism to prevent uncontrolled reactivity to antigens and inflammatory stimuli. The difficult task for the clinician, is to quantify the respective ratios and functions of “tolerant” vs. effector B-cells within a transplanted organ, at a given time point in order to modulate B-cell-directed therapy. Several receptors at the B-cell membrane as well as signaling molecules, can now be targeted for this purpose. Understanding the temporal expansion of regulatory B-cells in grafted patients and the stimuli that activate them will help in the future to implement specific strategies aimed at fighting chronic allograft

  14. TLR7 and TLR8 ligands and antiphospholipid antibodies show synergistic effects on the induction of IL-1beta and caspase-1 in monocytes and dendritic cells.

    PubMed

    Hurst, Julia; Prinz, Nadine; Lorenz, Mareike; Bauer, Stefan; Chapman, Joab; Lackner, Karl J; von Landenberg, Philipp

    2009-01-01

    TLRs represent the first line of defense against invading pathogens in the innate immune system. Certain cytokines are important mediators and essentially necessary to assure an appropriately regulated immune response. Recent data gave initial evidence that IL-1beta is one of the most relevant members of these regulating cytokines. We investigated the induction of IL-1beta production in monocytes and pDCs stimulated with ligands for TLR7 and TLR8 and with antiphospholipid antibodies (aPL). Using human monocytes and pDCs for stimulation with specific TLR7 and TLR8 ligands such as resiquimod (R848) and single stranded RNA (RNA42) as well as with a human monoclonal aPL HL5B resulted in a specific upregulation of IL-1beta mRNA and protein in these cells. Determination of expression-levels using real-time RT-PCR showed significantly augmented TLR-dependent IL-1beta and caspase-1 expression. This increase could be substantially enhanced by adding the monoclonal aPL HL5B. To demonstrate the direct dependency between TLR stimulation and IL-1beta production, specific TLR inhibitors were applied and the IL-1beta and caspase-1 secretion could be explicitly decreased. The respective protein levels were determined using Western Blot, FACS analysis or ELISA assays. In conclusion we demonstrated that the downstream signaling pathway of TLR7 and TLR8 in monocytes and pDCs after stimulation with specific ligands included not only the secretion of cytokines such as TNFalpha and IL-1beta but as well the activation of necessary regulating proteins like caspase-1. APL seem to enforce this process hinting that endogenous stimulation of TLRs in the Antiphospholipid Syndrome (APS) patients resulted in enhanced secretion of proinflammatory cytokines.

  15. Inability of Plasmacytoid Dendritic Cells To Directly Lyse HIV-Infected Autologous CD4+ T Cells despite Induction of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand ▿

    PubMed Central

    Chehimi, Jihed; Papasavvas, Emmanouil; Tomescu, Costin; Gekonge, Bethsebah; Abdulhaqq, Shaheed; Raymond, Andrea; Hancock, Aidan; Vinekar, Kavita; Carty, Craig; Reynolds, Griffin; Pistilli, Maxwell; Mounzer, Karam; Kostman, Jay; Montaner, Luis J.

    2010-01-01

    The function of plasmacytoid dendritic cells (PDC) in chronic human immunodeficiency virus type 1 (HIV-1) infection remains controversial with regard to its potential for sustained alpha interferon (IFN-α) production and induction of PDC-dependent tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-mediated cytotoxicity of HIV-infected cells. We address these areas by a study of chronically HIV-1-infected subjects followed through antiretroviral therapy (ART) interruption and by testing PDC cytolytic function against autologous HIV-infected CD4+ T cells. Rebound in viremia induced by therapy interruption showed a positive association between TRAIL and viral load or T-cell activation, but comparable levels of plasma IFN-α/β were found in viremic ART-treated and control subjects. While PDC from HIV-infected subjects expressed less interferon regulator factor 7 (IRF-7) and produced significantly less IFN-α upon Toll-like receptor 7/9 (TLR7/9) engagement than controls, membrane TRAIL expression in PDC from HIV+ subjects was increased. Moreover, no significant increase in death receptor 5 (DR5) expression was seen in CD4+ T cells from viremic HIV+ subjects compared to controls or following in vitro infection/exposure to infectious and noninfectious virus or exogenous IFN-α, respectively. Although activated PDC killed the DR5-expressing HIV-infected Sup-T1 cell line, PDC did not lyse primary autologous HIV+ CD4+ T cells yet could provide accessory help for NK cells in killing HIV-infected autologous CD4+ T cells. Taken together, our data show a lack of sustained high levels of soluble IFN-α in chronic HIV-1 infection in vivo and document a lack of direct PDC cytolytic activity against autologous infected or uninfected CD4+ T cells. PMID:20042498

  16. The unfolded protein response is required for dendrite morphogenesis.

    PubMed

    Wei, Xing; Howell, Audrey S; Dong, Xintong; Taylor, Caitlin A; Cooper, Roshni C; Zhang, Jianqi; Zou, Wei; Sherwood, David R; Shen, Kang

    2015-06-08

    Precise patterning of dendritic fields is essential for the formation and function of neuronal circuits. During development, dendrites acquire their morphology by exuberant branching. How neurons cope with the increased load of protein production required for this rapid growth is poorly understood. Here we show that the physiological unfolded protein response (UPR) is induced in the highly branched Caenorhabditis elegans sensory neuron PVD during dendrite morphogenesis. Perturbation of the IRE1 arm of the UPR pathway causes loss of dendritic branches, a phenotype that can be rescued by overexpression of the ER chaperone HSP-4 (a homolog of mammalian BiP/grp78). Surprisingly, a single transmembrane leucine-rich repeat protein, DMA-1, plays a major role in the induction of the UPR and the dendritic phenotype in the UPR mutants. These findings reveal a significant role for the physiological UPR in the maintenance of ER homeostasis during morphogenesis of large dendritic arbors.

  17. Epitope specificity plays a critical role in regulating antibody-dependent cell-mediated cytotoxicity against influenza A virus.

    PubMed

    He, Wenqian; Tan, Gene S; Mullarkey, Caitlin E; Lee, Amanda J; Lam, Mannie Man Wai; Krammer, Florian; Henry, Carole; Wilson, Patrick C; Ashkar, Ali A; Palese, Peter; Miller, Matthew S

    2016-10-18

    The generation of strain-specific neutralizing antibodies against influenza A virus is known to confer potent protection against homologous infections. The majority of these antibodies bind to the hemagglutinin (HA) head domain and function by blocking the receptor binding site, preventing infection of host cells. Recently, elicitation of broadly neutralizing antibodies which target the conserved HA stalk domain has become a promising "universal" influenza virus vaccine strategy. The ability of these antibodies to elicit Fc-dependent effector functions has emerged as an important mechanism through which protection is achieved in vivo. However, the way in which Fc-dependent effector functions are regulated by polyclonal influenza virus-binding antibody mixtures in vivo has never been defined. Here, we demonstrate that interactions among viral glycoprotein-binding antibodies of varying specificities regulate the magnitude of antibody-dependent cell-mediated cytotoxicity induction. We show that the mechanism responsible for this phenotype relies upon competition for binding to HA on the surface of infected cells and virus particles. Nonneutralizing antibodies were poor inducers and did not inhibit antibody-dependent cell-mediated cytotoxicity. Interestingly, anti-neuraminidase antibodies weakly induced antibody-dependent cell-mediated cytotoxicity and enhanced induction in the presence of HA stalk-binding antibodies in an additive manner. Our data demonstrate that antibody specificity plays an important role in the regulation of ADCC, and that cross-talk among antibodies of varying specificities determines the magnitude of Fc receptor-mediated effector functions.

  18. Induction of an antitumor response using dendritic cells transfected with DNA constructs encoding the HLA-A*02:01-restricted epitopes of tumor-associated antigens in culture of mononuclear cells of breast cancer patients.

    PubMed

    Sennikov, Sergey Vital'evich; Shevchenko, Julia Alexandrovna; Kurilin, Vasilii Vasil'evich; Khantakova, Julia Nikolaevna; Lopatnikova, Julia Anatol'evna; Gavrilova, Elena Vasil'evna; Maksyutov, Rinat Amirovich; Bakulina, Anastasiya Yur'evna; Sidorov, Sergey Vasil'evich; Khristin, Alexander Alexandrovich; Maksyutov, Amir Zakievich

    2016-02-01

    Advances in oncoimmunology related to the definition of the basic mechanisms of the formation of antitumor immune response, as well as the opening of tumor-associated antigens recognized by immune cells, allowed to start developing ways to influence the effector cells of the immune system to generate effective antitumor cytotoxic response. We investigated the possibility to stimulate an antitumor response in a culture of mononuclear cells of breast cancer patients by dendritic cells transfected with HLA-A*02:01-restricted DNA constructs. We isolated dendritic cells from peripheral blood monocytes and delivered our constructs to these cells by magnetic transfection. Additionally, a series of experiments with loading of dendritic cells with autologous tumor cell lysate antigens was conducted. We have shown that dendritic cells transfected with the HLA-A*02:01-restricted DNA constructs are effective in inducing an antitumor response in a culture of mononuclear cells of breast cancer patients. Dendritic cells transfected with DNA constructor dendritic cells loaded with lysate antigens revealed a comparable stimulated cytotoxic response of mononuclear cells to these two ways of antigen delivery. We conclude that using DNA constructs in conjunction with patient stratification by HLA type allows the application of transfected DCs as an effective method to stimulate antitumor immunity in vitro.

  19. A convergent and essential interneuron pathway for Mauthner-cell-mediated escapes.

    PubMed

    Lacoste, Alix M B; Schoppik, David; Robson, Drew N; Haesemeyer, Martin; Portugues, Ruben; Li, Jennifer M; Randlett, Owen; Wee, Caroline L; Engert, Florian; Schier, Alexander F

    2015-06-01

    The Mauthner cell (M-cell) is a command-like neuron in teleost fish whose firing in response to aversive stimuli is correlated with short-latency escapes [1-3]. M-cells have been proposed as evolutionary ancestors of startle response neurons of the mammalian reticular formation [4], and studies of this circuit have uncovered important principles in neurobiology that generalize to more complex vertebrate models [3]. The main excitatory input was thought to originate from multisensory afferents synapsing directly onto the M-cell dendrites [3]. Here, we describe an additional, convergent pathway that is essential for the M-cell-mediated startle behavior in larval zebrafish. It is composed of excitatory interneurons called spiral fiber neurons, which project to the M-cell axon hillock. By in vivo calcium imaging, we found that spiral fiber neurons are active in response to aversive stimuli capable of eliciting escapes. Like M-cell ablations, bilateral ablations of spiral fiber neurons largely eliminate short-latency escapes. Unilateral spiral fiber neuron ablations shift the directionality of escapes and indicate that spiral fiber neurons excite the M-cell in a lateralized manner. Their optogenetic activation increases the probability of short-latency escapes, supporting the notion that spiral fiber neurons help activate M-cell-mediated startle behavior. These results reveal that spiral fiber neurons are essential for the function of the M-cell in response to sensory cues and suggest that convergent excitatory inputs that differ in their input location and timing ensure reliable activation of the M-cell, a feedforward excitatory motif that may extend to other neural circuits.

  20. Early immunisation with dendritic cells after allogeneic bone marrow transplantation elicits graft vs tumour reactivity

    PubMed Central

    Gigi, V; Stein, J; Askenasy, N; Yaniv, I; Ash, S

    2013-01-01

    Background: Perspectives of immunotherapy to cancer mediated by bone marrow transplantation (BMT) in conjunction with dendritic cell (DC)-mediated immune sensitisation have yielded modest success so far. In this study, we assessed the impact of DC on graft vs tumour (GvT) reactions triggered by allogeneic BMT. Methods: H2Ka mice implanted with congenic subcutaneous Neuro-2a neuroblastoma (NB, H2Ka) tumours were irradiated and grafted with allogeneic H2Kb bone marrow cells (BMC) followed by immunisation with tumour-inexperienced or tumour-pulsed DC. Results: Immunisation with tumour-pulsed donor DC after allogeneic BMT suppressed tumour growth through induction of T cell-mediated NB cell lysis. Early post-transplant administration of DC was more effective than delayed immunisation, with similar efficacy of DC inoculated into the tumour and intravenously. In addition, tumour inexperienced DC were equally effective as tumour-pulsed DC in suppression of tumour growth. Immunisation of DC did not impact quantitative immune reconstitution, however, it enhanced T-cell maturation as evident from interferon-γ (IFN-γ) secretion, proliferation in response to mitogenic stimulation and tumour cell lysis in vitro. Dendritic cells potentiate GvT reactivity both through activation of T cells and specific sensitisation against tumour antigens. We found that during pulsing with tumour lysate DC also elaborate a factor that selectively inhibits lymphocyte proliferation, which is however abolished by humoral and DC-mediated lymphocyte activation. Conclusion: These data reveal complex involvement of antigen-presenting cells in GvT reactions, suggesting that the limited success in clinical application is not a result of limited efficacy but suboptimal implementation. Although DC can amplify soluble signals from NB lysates that inhibit lymphocyte proliferation, early administration of DC is a dominant factor in suppression of tumour growth. PMID:23511628

  1. Dendritic microstructure in argon atomized superalloy powders

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.; Kumar, Mahundra

    1986-01-01

    The dendritic microstructure of atomized nickel base superalloy powders (Ni-20 pct Cr, NIMONIC-80A, ASTROALOY, and ZHS6-K) was studied. Prealloyed vacuum induction melted ingots were argon-atomized, the powders were cooled to room temperature, and various powder-size fractions were examined by optical metallography. Linear correlations were obtained for the powder size dependence of the secondary dendrite arm spacing, following the expected d-alpha (R) to the m power dependence on the particle size for all four superalloy compositions. However, the Ni-20 pct Cr alloy, which had much coarser arm spacing as compared to the other three alloys, had a much larger value of m.

  2. Spike-timing-dependent synaptic plasticity depends on dendritic location

    NASA Astrophysics Data System (ADS)

    Froemke, Robert C.; Poo, Mu-ming; Dan, Yang

    2005-03-01

    In the neocortex, each neuron receives thousands of synaptic inputs distributed across an extensive dendritic tree. Although postsynaptic processing of each input is known to depend on its dendritic location, it is unclear whether activity-dependent synaptic modification is also location-dependent. Here we report that both the magnitude and the temporal specificity of spike-timing-dependent synaptic modification vary along the apical dendrite of rat cortical layer 2/3 pyramidal neurons. At the distal dendrite, the magnitude of long-term potentiation is smaller, and the window of pre-/postsynaptic spike interval for long-term depression (LTD) is broader. The spike-timing window for LTD correlates with the window of action potential-induced suppression of NMDA (N-methyl-D-aspartate) receptors; this correlation applies to both their dendritic location-dependence and pharmacological properties. Presynaptic stimulation with partial blockade of NMDA receptors induced LTD and occluded further induction of spike-timing-dependent LTD, suggesting that NMDA receptor suppression underlies LTD induction. Computer simulation studies showed that the dendritic inhomogeneity of spike-timing-dependent synaptic modification leads to differential input selection at distal and proximal dendrites according to the temporal characteristics of presynaptic spike trains. Such location-dependent tuning of inputs, together with the dendritic heterogeneity of postsynaptic processing, could enhance the computational capacity of cortical pyramidal neurons.

  3. Detection of cell mediated immune response to avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In birds, lymphomyeloid tissues develop from epithelial (Bursa of Fabricus or thymus) or mesenchymal tissue which are populated by heamatopoietic stem cells. These stem cells develop directly into immunologically competent B (bursa) and T (thymus) cells. Cell-mediated immunity (CMI) is a part of the...

  4. Isothermal Dendritic Growth Experiment - PVA Dendrites

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Isothermal Dendritic Growth Experiment (IDGE), flown on three Space Shuttle missions, is yielding new insights into virtually all industrially relevant metal and alloy forming operations. IDGE used transparent organic liquids that form dendrites (treelike structures) similar to those inside metal alloys. Comparing Earth-based and space-based dendrite growth velocity, tip size and shape provides a better understanding of the fundamentals of dentritic growth, including gravity's effects. Shalowgraphic images of pivalic acid (PVA) dendrites forming from the melt show the subtle but distinct effects of gravity-driven heat convection on dentritic growth. In orbit, the dendrite grows as its latent heat is liberated by heat conduction. This yields a blunt dendrite tip. On Earth, heat is carried away by both conduction and gravity-driven convection. This yields a sharper dendrite tip. In addition, under terrestrial conditions, the sidebranches growing in the direction of gravity are augmented as gravity helps carry heat out of the way of the growing sidebranches as opposed to microgravity conditions where no augmentation takes place. IDGE was developed by Rensselaer Polytechnic Institute and NASA/Glenn Research Center. Advanced follow-on experiments are being developed for flight on the International Space Station. Photo Credit: NASA/Glenn Research Center

  5. Targeting dendritic cells--why bother?

    PubMed

    Kreutz, Martin; Tacken, Paul J; Figdor, Carl G

    2013-04-11

    Vaccination is among the most efficient forms of immunotherapy. Although sometimes inducing lifelong protective B-cell responses, T-cell-mediated immunity remains challenging. Targeting antigen to dendritic cells (DCs) is an extensively explored concept aimed at improving cellular immunity. The identification of various DC subsets with distinct functional characteristics now allows for the fine-tuning of targeting strategies. Although some of these DC subsets are regarded as superior for (cross-) priming of naive T cells, controversies still remain about which subset represents the best target for immunotherapy. Because targeting the antigen alone may not be sufficient to obtain effective T-cell responses, delivery systems have been developed to target multiple vaccine components to DCs. In this Perspective, we discuss the pros and cons of targeting DCs: if targeting is beneficial at all and which vaccine vehicles and immunization routes represent promising strategies to reach and activate DCs.

  6. Self-adjuvanting influenza candidate vaccine presenting epitopes for cell-mediated immunity on a proteinaceous multivalent nanoplatform.

    PubMed

    Szurgot, Inga; Szolajska, Ewa; Laurin, David; Lambrecht, Benedicte; Chaperot, Laurence; Schoehn, Guy; Chroboczek, Jadwiga

    2013-09-13

    We exploit the features of a virus-like particle, adenoviral dodecahedron (Ad Dd), for engineering a multivalent vaccination platform carrying influenza epitopes for cell-mediated immunity. The delivery platform, Ad Dd, is a proteinaceous, polyvalent, and biodegradable nanoparticle endowed with remarkable endocytosis activity that can be engineered to carry 60 copies of a peptide. Influenza M1 is the most abundant influenza internal protein with the conserved primary structure. Two different M1 immunodominant epitopes were separately inserted in Dd external positions without destroying the particles' dodecahedric structure. Both kinds of DdFluM1 obtained through expression in baculovirus system were properly presented by human dendritic cells triggering efficient activation of antigen-specific T cells responses. Importantly, the candidate vaccine was able to induce cellular immunity in vivo in chickens. These results warrant further investigation of Dd as a platform for candidate vaccine, able to stimulate cellular immune responses.

  7. Free dendritic growth

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.

    1984-01-01

    Free dendritic growth refers to the unconstrained development of crystals within a supercooled melt, which is the classical 'dendrite problem'. Great strides have been taken in recent years in both the theoretical understanding of dendritic growth and its experimental status. The development of this field will be sketched, showing that transport theory and interfacial thermodynamics (capillarity theory) were sufficient ingredients to develop a truly predictive model of dendrite formation. The convenient, but incorrect, notion of 'maximum velocity' was used for many years to estimate the behavior of dendritic transformations until supplanted by modern dynamic stability theory. The proper combinations of transport theory and morphological stability seem to able to predict the salient aspects of dendritic growth, especially in the neighborhood of the tip. The overall development of cast microstructures, such as equiaxed zone formation, rapidly solidified microstructures, etc., also seems to contain additional non-deterministic features which lie outside the current theories discussed here.

  8. Dendritic polyurea polymers.

    PubMed

    Tuerp, David; Bruchmann, Bernd

    2015-01-01

    Dendritic polymers, subsuming dendrimers as well as hyperbranched or highly branched polymers are well established in the field of polymer chemistry. This review article focuses on urea based dendritic polymers and summarizes their synthetic routes through both isocyanate and isocyanate-free processes. Furthermore, this article highlights applications where dendritic polyureas show their specific chemical and physical potential. For these purposes scientific publications as well as patent literature are investigated to generate a comprehensive overview on this topic.

  9. Effect of space flight on cell-mediated immunity

    NASA Technical Reports Server (NTRS)

    Mandel, A. D.; Balish, E.

    1977-01-01

    The cell-mediated immune response to Listeria monocytogenes was studied in rats subjected to 20 days of flight aboard the Soviet biosatellite Kosmos 7820. Groups of rats were immunized with 1,000,000 formalin-killed Listeria suspended in Freunds Complete Adjuvant, 5 days prior to flight. Immunized rats subjected to the same environmental factors as the flight rats, except flight itself, and immunized and nonimmunized rats held in a normal animal colony served as controls. Following recovery, lymphocyte cultures were harvested from spleens of all rats, cultured in vitro in the presence of L. monocytogenes antigens, Phytohemagglutinin, Conconavlin A, or purified protein derivative (PPD), and measured for their uptake of H-3-thymidine. Although individual rats varied considerably, all flight and immunized control rats gave a blastogenic response to the Listeria antigens and PPD. With several mitogens, the lymphocytes of flight rats showed a significantly increased blastogenic response over the controls. The results of this study do not support a hypothesis of a detrimental effect of space flight on cell-mediated immunity. The data suggest a possible suppressive effect of stress and gravity on an in vitro correlate of cell-mediated immunity.

  10. Cord blood T cells mediate enhanced antitumor effects compared with adult peripheral blood T cells.

    PubMed

    Hiwarkar, Prashant; Qasim, Waseem; Ricciardelli, Ida; Gilmour, Kimberly; Quezada, Sergio; Saudemont, Aurore; Amrolia, Persis; Veys, Paul

    2015-12-24

    Unrelated cord blood transplantation (CBT) without in vivo T-cell depletion is increasingly used to treat high-risk hematologic malignancies. Following T-replete CBT, naïve CB T cells undergo rapid peripheral expansion with memory-effector differentiation. Emerging data suggest that unrelated CBT, particularly in the context of HLA mismatch and a T-replete graft, may reduce leukemic relapse. To study the role of CB T cells in mediating graft-versus-tumor responses and dissect the underlying immune mechanisms for this, we compared the ability of HLA-mismatched CB and adult peripheral blood (PB) T cells to eliminate Epstein-Barr virus (EBV)-driven human B-cell lymphoma in a xenogeneic NOD/SCID/IL2rg(null) mouse model. CB T cells mediated enhanced tumor rejection compared with equal numbers of PB T cells, leading to improved survival in the CB group (P < .0003). Comparison of CB T cells that were autologous vs allogeneic to the lymphoma demonstrated that this antitumor effect was mediated by alloreactive rather than EBV-specific T cells. Analysis of tumor-infiltrating lymphocytes demonstrated that CB T cells mediated this enhanced antitumor effect by rapid infiltration of the tumor with CCR7(+)CD8(+) T cells and prompt induction of cytotoxic CD8(+) and CD4(+) T-helper (Th1) T cells in the tumor microenvironment. In contrast, in the PB group, this antilymphoma effect is impaired because of delayed tumoral infiltration of PB T cells and a relative bias toward suppressive Th2 and T-regulatory cells. Our data suggest that, despite being naturally programmed toward tolerance, reconstituting T cells after unrelated T-replete CBT may provide superior Tc1-Th1 antitumor effects against high-risk hematologic malignancies.

  11. Impairment in natural killer cells editing of immature dendritic cells by infection with a virulent Trypanosoma cruzi population.

    PubMed

    Batalla, Estela I; Pino Martínez, Agustina M; Poncini, Carolina V; Duffy, Tomás; Schijman, Alejandro G; González Cappa, Stella M; Alba Soto, Catalina D

    2013-01-01

    Early interactions between natural killer (NK) and dendritic cells (DC) shape the immune response at the frontier of innate and adaptive immunity. Activated NK cells participate in maturation or deletion of DCs that remain immature. We previously demonstrated that infection with a high virulence (HV) population of the protozoan parasite Trypanosoma cruzi downmodulates DC maturation and T-cell activation capacity. Here, we evaluated the role of NK cells in regulating the maturation level of DCs. Shortly after infection with HV T. cruzi, DCs in poor maturation status begin to accumulate in mouse spleen. Although infection induces NK cell cytotoxicity and cytokine production, NK cells from mice infected with HV T. cruzi exhibit reduced ability to lyse and fail to induce maturation of bone marrow-derived immature DCs (iDCs). NK-mediated lysis of iDCs is restored by in vitro blockade of the IL-10 receptor during NK-DC interaction or when NK cells are obtained from T. cruzi-infected IL-10 knockout mice. These results suggest that infection with a virulent T. cruzi strain alters NK cell-mediated regulation of the adaptive immune response induced by DCs. This regulatory circuit where IL-10 appears to participate might lead to parasite persistence but can also limit the induction of a vigorous tissue-damaging T-cell response.

  12. Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

    PubMed

    Heit, Antje; Gebhardt, Friedemann; Lahl, Katharina; Neuenhahn, Michael; Schmitz, Frank; Anderl, Florian; Wagner, Hermann; Sparwasser, Tim; Busch, Dirk H; Kastenmüller, Kathrin

    2008-06-01

    Immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained CD8(+) T cell-mediated protection against intracellular pathogens. Most efforts to improve the CD8(+) T cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. In addition, it has been shown that CD4(+) T cell help during the priming phase contributes to the generation of protective CD8(+) memory T cells. In this report we demonstrate that the depletion of CD4(+) T cells paradoxically enhances long-lasting CD8-mediated protective immunity upon protein vaccination. Functional and genetic in vivo inactivation experiments attribute this enhancement primarily to MHC class II-restricted CD4(+) regulatory T cells (Treg), which appear to physiologically suppress the differentiation process towards long-living effector memory T cells. Since, in functional terms, this suppression by Treg largely exceeds the positive effects of conventional CD4(+) T cell help, even the absence of all CD4(+) T cells or lack of MHC class II-mediated interactions on priming dendritic cells result in enhanced CD8(+) T cell immunogenicity. These findings have important implications for the improvement of vaccines against intracellular pathogens or tumors, especially in patients with highly active Treg.

  13. Comparative measurement of cell-mediated immune responses of swine to the M and N proteins of porcine reproductive and respiratory syndrome virus.

    PubMed

    Jeong, Hyun-Jeong; Song, Young-Jo; Lee, Sang-Won; Lee, Joong-Bok; Park, Seung-Yong; Song, Chang-Seon; Ha, Gun-Woo; Oh, Jin-Sik; Oh, Youn-Kyoung; Choi, In-Soo

    2010-04-01

    the induction of cell-mediated immunity.

  14. The Ebola Interferon Inhibiting Domains Attenuate and Dysregulate Cell-Mediated Immune Responses

    PubMed Central

    Meyer, Michelle; Koup, Richard A.; Bukreyev, Alexander

    2016-01-01

    Ebola virus (EBOV) infections are characterized by deficient T-lymphocyte responses, T-lymphocyte apoptosis and lymphopenia. We previously showed that disabling of interferon-inhibiting domains (IIDs) in the VP24 and VP35 proteins effectively unblocks maturation of dendritic cells (DCs) and increases the secretion of cytokines and chemokines. Here, we investigated the role of IIDs in adaptive and innate cell-mediated responses using recombinant viruses carrying point mutations, which disabled IIDs in VP24 (EBOV/VP24m), VP35 (EBOV/VP35m) or both (EBOV/VP35m/VP24m). Peripheral blood mononuclear cells (PBMCs) from cytomegalovirus (CMV)-seropositive donors were inoculated with the panel of viruses and stimulated with CMV pp65 peptides. Disabling of the VP35 IID resulted in increased proliferation and higher percentages of CD4+ T cells secreting IFNγ and/or TNFα. To address the role of aberrant DC maturation in the IID-mediated suppression of T cell responses, CMV-stimulated DCs were infected with the panel of viruses and co-cultured with autologous T-lymphocytes. Infection with EBOV/VP35m infection resulted in a significant increase, as compared to wt EBOV, in proliferating CD4+ cells secreting IFNγ, TNFα and IL-2. Experiments with expanded CMV-specific T cells demonstrated their increased activation following co-cultivation with CMV-pulsed DCs pre-infected with EBOV/VP24m, EBOV/VP35m and EBOV/VP35m/VP24m, as compared to wt EBOV. Both IIDs were found to block phosphorylation of TCR complex-associated adaptors and downstream signaling molecules. Next, we examined the effects of IIDs on the function of B cells in infected PBMC. Infection with EBOV/VP35m and EBOV/VP35m/VP24m resulted in significant increases in the percentages of phenotypically distinct B-cell subsets and plasma cells, as compared to wt EBOV, suggesting inhibition of B cell function and differentiation by VP35 IID. Finally, infection with EBOV/VP35m increased activation of NK cells, as compared to wt

  15. Induction of antigen-specific immunity by pH-sensitive carbonate apatite as a potent vaccine carrier

    SciTech Connect

    Hebishima, Takehisa; Tada, Seiichi; Takeshima, Shin-nosuke; Akaike, Toshihiro; Ito, Yoshihiro; Aida, Yoko

    2011-12-02

    Highlights: Black-Right-Pointing-Pointer To develop effective vaccine, we examined the effects of CO{sub 3}Ap as an antigen carrier. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap was taken up by BMDCs more effectively than free OVA. Black-Right-Pointing-Pointer OVA-immunized splenocytes was activated by OVA contained in CO{sub 3}Ap effectively. Black-Right-Pointing-Pointer OVA contained in CO{sub 3}Ap induced strong OVA-specific immune responses to C57BL/6 mice. Black-Right-Pointing-Pointer CO{sub 3}Ap is promising antigen carrier for the achievement of effective vaccine. -- Abstract: The ability of carbonate apatite (CO{sub 3}Ap) to enhance antigen-specific immunity was examined in vitro and in vivo to investigate its utility as a vaccine carrier. Murine bone marrow-derived dendritic cells took up ovalbumin (OVA) containing CO{sub 3}Ap more effectively than free OVA. Interestingly, mice immunized with OVA-containing CO{sub 3}Ap produced OVA-specific antibodies more effectively than mice immunized with free OVA. Furthermore, immunization of C57BL/6 mice with OVA-containing CO{sub 3}Ap induced the proliferation and antigen-specific production of IFN-{gamma} by splenocytes more strongly than immunization with free OVA. Moreover, no significant differences were detected in the induction of delayed-type hypersensitivity responses, an immune reaction involving an antigen-specific, cell-mediated immune response between OVA-containing CO{sub 3}Ap and OVA-containing alumina salt (Alum), suggesting that CO{sub 3}Ap induced cell-mediated immune response to the same degree as Alum, which is commonly used for clinical applications. This study is the first to demonstrate the induction of antigen-specific immune responses in vivo by CO{sub 3}Ap.

  16. Dendrite Model Explained

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Angie Jackman, a NASA project manager in microgravity research, explains a model of a dendrite to a visitor to the NASA exhibit at AirVenture 2000 sponsored by the Experimental Aircraft Association in Oshkosh, WI. The model depicts microscopic dendrites that grow as molten metals solidify. NASA sponsored three experiments aboard the Space Shuttle that used the microgravity environment to study the formation of large (1 to 4 mm) dendrites without Earth's gravity disrupting their growth. Three advanced follow-on experiments, managed by Jackman, are being developed for the International Space Station (ISS).

  17. Protamine and mast-cell-mediated angiogenesis in the rat.

    PubMed Central

    Jakobsson, A.; Sörbo, J.; Norrby, K.

    1990-01-01

    Different doses of protamine sulphate (PS) given s.c. (at 12-h intervals) were tested for signs of non-specific toxicity measured as effect on body weight and small-gut proliferation as well as on mast-cell secretion and mast-cell-mediated mitogenesis in the mesenteric windows following i.p. injection of Compound 48/80, a potent mast cell secretagogue, in normal rats. In a non-toxic dose range, the effect of PS on mast-cell-mediated angiogenesis, effected by 48/80, was quantified as the number of vessels per mm of mesenteric window in histological sections at x 400. No intelligible dose-effect relationship was discernible between the dose of PS given and the effect on angiogenesis. Only in a tight interval, at 40 mg PS/kg but not at 20 or 60 mg PS/kg, was the angiogenesis statistically significantly suppressed. Hence, it was concluded that PS can be angiostatic but does not exert a more general angiostatic effect in the autogenous systems used. PMID:1691920

  18. Fitness of cell-mediated immunity independent of repertoire diversity.

    PubMed

    AbuAttieh, Mouhammed; Rebrovich, Michelle; Wettstein, Peter J; Vuk-Pavlovic, Zvezdana; Limper, Andrew H; Platt, Jeffrey L; Cascalho, Marilia

    2007-03-01

    Fitness of cell-mediated immunity is thought to depend on TCR diversity; however, this concept has not been tested formally. We tested the concept using JH(-/-) mice that lack B cells and have TCR Vbeta diversity <1% that of wild-type mice and quasimonoclonal (QM) mice with oligoclonal B cells and TCR Vbeta diversity 7% that of wild-type mice. Despite having a TCR repertoire contracted >99% and defective lymphoid organogenesis, JH(-/-) mice rejected H-Y-incompatible skin grafts as rapidly as wild-type mice. JH(-/-) mice exhibited T cell priming by peptide and delayed-type hypersensitivity, although these responses were less than normal owing either to TCR repertoire contraction or defective lymphoid organogenesis. QM mice with TCR diversity contracted >90%, and normal lymphoid organs rejected H-Y incompatible skin grafts as rapidly as wild type mice and exhibited normal T cell priming and normal delayed-type hypersensitivity reactions. QM mice also resisted Pneumocystis murina like wild-type mice. Thus, cell-mediated immunity can function normally despite contractions of TCR diversity >90% and possibly >99%.

  19. Dendritic Growth Investigators

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Representatives of NASA materials science experiments supported the NASA exhibit at the Rernselaer Polytechnic Institute's Space Week activities, April 5 through 11, 1999. From left to right are: Angie Jackman, project manager at NASA's Marshall Space Flight Center for dendritic growth experiments; Dr. Martin Glicksman of Rennselaer Polytechnic Instutute, Troy, NY, principal investigator on the Isothermal Dendritic Growth Experiment (IDGE) that flew three times on the Space Shuttle; and Dr. Matthew Koss of College of the Holy Cross in Worcester, MA, a co-investigator on the IDGE and now principal investigator on the Transient Dendritic Solidification Experiment being developed for the International Space Station (ISS). The image at far left is a dendrite grown in Glicksman's IDGE tests aboard the Shuttle. Glicksman is also principal investigator for the Evolution of Local Microstructures: Spatial Instabilities of Coarsening Clusters.

  20. Dendritic Synapse Location and Neocortical Spike-Timing-Dependent Plasticity

    PubMed Central

    Froemke, Robert C.; Letzkus, Johannes J.; Kampa, Björn M.; Hang, Giao B.; Stuart, Greg J.

    2010-01-01

    While it has been appreciated for decades that synapse location in the dendritic tree has a powerful influence on signal processing in neurons, the role of dendritic synapse location on the induction of long-term synaptic plasticity has only recently been explored. Here, we review recent work revealing how learning rules for spike-timing-dependent plasticity (STDP) in cortical neurons vary with the spatial location of synaptic input. A common principle appears to be that proximal synapses show conventional STDP, whereas distal inputs undergo plasticity according to novel learning rules. One crucial factor determining location-dependent STDP is the backpropagating action potential, which tends to decrease in amplitude and increase in width as it propagates into the dendritic tree of cortical neurons. We discuss additional location-dependent mechanisms as well as the functional implications of heterogeneous learning rules at different dendritic locations for the organization of synaptic inputs. PMID:21423515

  1. Comparative analyses of humoral and cell-mediated immune responses upon vaccination with different commercially available single-dose porcine circovirus type 2 vaccines.

    PubMed

    Seo, Hwi Won; Lee, Jeehoon; Han, Kiwon; Park, Changhoon; Chae, Chanhee

    2014-08-01

    The objective of this study was to compare the induction of humoral and cell-mediated immune responses by four commercially available single-dose porcine circovirus type 2 (PCV-2) vaccines. A total of 50 3-week-old piglets were assigned to five groups (10 pigs per group). Four commercial PCV-2 vaccines were administered according to the manufacturer's instructions and the piglets were observed for 154 days post vaccination (dpv). Inactivated chimeric PCV-1-2 vaccines induced higher levels of PCV-2-specific neutralizing antibodies (NA) and interferon-γ-secreting cells (IFN-γ-SC) in pigs than did the other three commercial PCV-2 vaccines. The proportions of CD4(+) cells were significantly higher in animals vaccinated with inactivated chimeric PCV-1-2 and PCV-2 vaccines than in animals vaccinated with the two subunit vaccines. To our knowledge, this is the first comparison of humoral and cell-mediated immunity induced by four commercial single-dose PCV-2 vaccines under the same conditions. The results of this study demonstrated quantitative differences in the induction of humoral and cell-mediated immunity following vaccination.

  2. Isothermal Dendritic Growth Experiment - SCN Dendrites

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Isothermal Dendritic Growth Experiment (IDGE), flown on three Space Shuttle missions, is yielding new insights into virtually all industrially relevant metal and alloy forming operations. IDGE used transparent organic liquids that form dendrites (treelike structures) similar to the crystals that form inside metal alloys. Comparing Earth-based and space-based dentrite growth velocity, tip size and shape provid a better understanding of the fundamentals of dentritic growth, including gravity's effects. These shadowgraphic images show succinonitrile (SCN) dentrites growing in a melt (liquid). The space-grown crystals also have cleaner, better defined sidebranches. IDGE was developed by Rensselaer Polytechnic Institude (RPI) and NASA/ Glenn Research Center(GRC). Advanced follow-on experiments are being developed for flight on the International Space Station. Photo gredit: NASA/Glenn Research Center

  3. Enterovirus-71 Virus-Like Particles Induce the Activation and Maturation of Human Monocyte-Derived Dendritic Cells through TLR4 Signaling

    PubMed Central

    Lin, Yu-Li; Hu, Yu-Chen; Liang, Cheng-Chao; Lin, Shih-Yeh; Liang, Yu-Chih; Yuan, Hui-Ping; Chiang, Bor-Luen

    2014-01-01

    Enterovirus 71 (EV71) causes seasonal epidemics of hand-foot-and-mouth disease and has a high mortality rate among young children. We recently demonstrated potent induction of the humoral and cell-mediated immune response in monkeys immunized with EV71 virus-like particles (VLPs), with a morphology resembling that of infectious EV71 virions but not containing a viral genome, which could potentially be safe as a vaccine for EV71. To elucidate the mechanisms through which EV71 VLPs induce cell-mediated immunity, we studied the immunomodulatory effects of EV71 VLPs on human monocyte-derived dendritic cells (DCs), which bind to and incorporate EV71 VLPs. DC treatment with EV71 VLPs enhanced the expression of CD80, CD86, CD83, CD40, CD54, and HLA-DR on the cell surface; increased the production of interleukin (IL)-12 p40, IL-12 p70, and IL-10 by DCs; and suppressed the capacity of DCs for endocytosis. Treatment with EV71 VLPs also enhanced the ability of DCs to stimulate naïve T cells and induced secretion of interferon (IFN)-γ by T cells and Th1 cell responses. Neutralization with antibodies against Toll-like receptor (TLR) 4 suppressed the capacity of EV71 VLPs to induce the production of IL-12 p40, IL-12 p70, and IL-10 by DCs and inhibited EV71 VLPs binding to DCs. Our study findings clarified the important role for TLR4 signaling in DCs in response to EV71 VLPs and showed that EV71 VLPs induced inhibitor of kappaB alpha (IκBα) degradation and nuclear factor of kappaB (NF-κB) activation. PMID:25360749

  4. Enterovirus-71 virus-like particles induce the activation and maturation of human monocyte-derived dendritic cells through TLR4 signaling.

    PubMed

    Lin, Yu-Li; Hu, Yu-Chen; Liang, Cheng-Chao; Lin, Shih-Yeh; Liang, Yu-Chih; Yuan, Hui-Ping; Chiang, Bor-Luen

    2014-01-01

    Enterovirus 71 (EV71) causes seasonal epidemics of hand-foot-and-mouth disease and has a high mortality rate among young children. We recently demonstrated potent induction of the humoral and cell-mediated immune response in monkeys immunized with EV71 virus-like particles (VLPs), with a morphology resembling that of infectious EV71 virions but not containing a viral genome, which could potentially be safe as a vaccine for EV71. To elucidate the mechanisms through which EV71 VLPs induce cell-mediated immunity, we studied the immunomodulatory effects of EV71 VLPs on human monocyte-derived dendritic cells (DCs), which bind to and incorporate EV71 VLPs. DC treatment with EV71 VLPs enhanced the expression of CD80, CD86, CD83, CD40, CD54, and HLA-DR on the cell surface; increased the production of interleukin (IL)-12 p40, IL-12 p70, and IL-10 by DCs; and suppressed the capacity of DCs for endocytosis. Treatment with EV71 VLPs also enhanced the ability of DCs to stimulate naïve T cells and induced secretion of interferon (IFN)-γ by T cells and Th1 cell responses. Neutralization with antibodies against Toll-like receptor (TLR) 4 suppressed the capacity of EV71 VLPs to induce the production of IL-12 p40, IL-12 p70, and IL-10 by DCs and inhibited EV71 VLPs binding to DCs. Our study findings clarified the important role for TLR4 signaling in DCs in response to EV71 VLPs and showed that EV71 VLPs induced inhibitor of kappaB alpha (IκBα) degradation and nuclear factor of kappaB (NF-κB) activation.

  5. CD8+ immunoregulatory cells in the graft-versus-host reaction: CD8 T cells activate dendritic cells to secrete interleukin-12/interleukin-18 and induce T helper 1 autoantibody

    PubMed Central

    Noble, Alistair; Leggat, Jamie A; Inderberg, Else M

    2003-01-01

    Initiation of cell-mediated immunity or autoimmunity requires secretion of interleukin (IL)-12 from dendritic cells (DC), which drives the generation of T helper 1 (Th1) effector cells in synergy with IL-18. Induction of IL-12 can be triggered by microbial stimuli but also requires signals from activated T cells. We investigated interactions between alloreactive CD4 and CD8 T cells in mixed lymphocyte reactions (MLR) in vitro and in the graft-versus-host reaction (GVHR) in vivo. In a parent-into-F1 model of GVHR, donor CD8 cells were found to suppress the hyper-immunoglobulin E (IgE) syndrome, anti-DNA immunoglobulin G1 (IgG1) autoantibodies and donor CD4-cell expansion, but were essential for Th1-dependent immunoglobulin G2a (IgG2a) autoantibody production and release of serum IL-12 p40. In vitro, addition of alloreactive CD8 cells to CD4 cells and mature DC enhanced Th1 development. CD4 and CD8 T cells induced IL-18 from DC and primed for IL-12 p70 secretion via interferon-γ (IFN-γ) or tumour necrosis factor-α (TNF-α). However CD8 T cells, but not CD4 cells, released IFN-γ/TNF-α after primary stimulation. The data suggest that rapid release of inflammatory cytokines from central memory-type CD8 cells early in immunity is critical for induction of Th1 cells via DC activation and IL-12 production. This pathway could provide a means for amplification of cell-mediated autoimmunity in the absence of microbial stimuli. PMID:12871213

  6. Lid for improved dendritic web growth

    DOEpatents

    Duncan, Charles S.; Kochka, Edgar L.; Piotrowski, Paul A.; Seidensticker, Raymond G.

    1992-03-24

    A lid for a susceptor in which a crystalline material is melted by induction heating to form a pool or melt of molten material from which a dendritic web of essentially a single crystal of the material is pulled through an elongated slot in the lid and the lid has a pair of generally round openings adjacent the ends of the slot and a groove extends between each opening and the end of the slot. The grooves extend from the outboard surface of the lid to adjacent the inboard surface providing a strip contiguous with the inboard surface of the lid to produce generally uniform radiational heat loss across the width of the dendritic web adjacent the inboard surface of the lid to reduce thermal stresses in the web and facilitate the growth of wider webs at a greater withdrawal rate.

  7. Establishment of Stable, Cell-Mediated Immunity that Makes "Susceptible" Mice Resistant to Leishmania major

    NASA Astrophysics Data System (ADS)

    Bretscher, Peter A.; Wei, Guojian; Menon, Juthika N.; Bielefeldt-Ohmann, Helle

    1992-07-01

    Cell-mediated, but not antibody-mediated, immune responses protect humans against certain pathogens that produce chronic diseases such as leishmaniasis. Effective vaccination against such pathogens must therefore produce an immunological "imprint" so that stable, cell-mediated immunity is induced in all individuals after natural infection. BALB/c mice "innately susceptible" to Leishmania major produce antibodies after substantial infection. In the present study, "susceptible" mice injected with a small number of parasites mounted a cell-mediated response and acquired resistance to a larger, normally pathogenic, challenge. This vaccination strategy may be applicable in diseases in which protection is dependent on cell-mediated immunity.

  8. Molecular imaging of cell-mediated cancer immunotherapy.

    PubMed

    Lucignani, Giovanni; Ottobrini, Luisa; Martelli, Cristina; Rescigno, Maria; Clerici, Mario

    2006-09-01

    New strategies based on the activation of a patient's immune response are being sought to complement present conventional exogenous cancer therapies. Elucidating the trafficking pathways of immune cells in vivo, together with their migratory properties in relation to their differentiation and activation status, is useful for understanding how the immune system interacts with cancer. Methods based on tissue sampling to monitor immune responses are inadequate for repeatedly characterizing the responses of the immune system in different organs. A solution to this problem might come from molecular and cellular imaging - a branch of biomedical sciences that combines biotechnology and imaging methods to characterize, in vivo, the molecular and cellular processes involved in normal and pathologic states. The general concepts of noninvasive imaging of targeted cells as well as the technology and probes applied to cell-mediated cancer immunotherapy imaging are outlined in this review.

  9. Active properties of neuronal dendrites.

    PubMed

    Johnston, D; Magee, J C; Colbert, C M; Cristie, B R

    1996-01-01

    Dendrites of neurons in the central nervous system are the principal sites for excitatory synaptic input. Although little is known about their function, two disparate perspectives have arisen to describe the activity patterns inherent to these diverse tree-like structures. Dendrites are thus considered either passive or active in their role in integrating synaptic inputs. This review follows the history of dendritic research from before the turn of the century to the present, with a primary focus on the hippocampus. A number of recent techniques, including high-speed fluorescence imaging and dendritic patch clamping, have provided new information and perspectives about the active properties of dendrites. The results support previous notions about the dendritic propagation of action potentials and also indicate which types of voltage-gated sodium and calcium channels are expressed and functionally active in dendrites. Possible roles for the active properties of dendrites in synaptic plasticity and integration are also discussed.

  10. Longitudinal Tracking of Human Dendritic Cells in Murine Models Using Magnetic Resonance Imaging

    PubMed Central

    Briley-Saebo, Karen C.; Leboeuf, Marylene; Dickson, Stephen; Mani, Venkatesh; Fayad, Zahi A.; Palucka, A. Karolina; Banchereau, Jacques; Merad, Miriam

    2011-01-01

    Ex vivo generated dendritic cells are currently used to induce therapeutic immunity in solid tumors. Effective immune response requires dendritic cells to home and remain in lymphoid organs to allow for adequate interaction with T lymphocytes. The aim of the current study was to detect and track Feridex labeled human dendritic cells in murine models using magnetic resonance imaging. Human dendritic cells were incubated with Feridex and the effect of labeling on dendritic cells immune function was evaluated. Ex vivo dendritic cell phantoms were used to estimate sensitivity of the magnetic resonance methods and in vivo homing was evaluated after intravenous or subcutaneous injection. R2*-maps of liver, spleen, and draining lymph nodes were obtained and inductively coupled plasma mass spectrometry or relaxometry methods were used to quantify the Feridex tissue concentrations. Correlations between in vivo R2* values and iron content were then determined. Feridex labeling did not affect dendritic cell maturation or function. Phantom results indicated that it was possible to detect 125 dendritic cells within a given slice. Strong correlation between in vivo R2* values and iron deposition was observed. Importantly, Feridex-labeled dendritic cells were detected in the spleen for up to 2 weeks postintravenous injection. This study suggests that magnetic resonance imaging may be used to longitudinally track Feridex-labeled human dendritic cells for up to 2 weeks after injection. PMID:20593373

  11. Dendritic Polymers for Theranostics

    PubMed Central

    Ma, Yuan; Mou, Quanbing; Wang, Dali; Zhu, Xinyuan; Yan, Deyue

    2016-01-01

    Dendritic polymers are highly branched polymers with controllable structures, which possess a large population of terminal functional groups, low solution or melt viscosity, and good solubility. Their size, degree of branching and functionality can be adjusted and controlled through the synthetic procedures. These tunable structures correspond to application-related properties, such as biodegradability, biocompatibility, stimuli-responsiveness and self-assembly ability, which are the key points for theranostic applications, including chemotherapeutic theranostics, biotherapeutic theranostics, phototherapeutic theranostics, radiotherapeutic theranostics and combined therapeutic theranostics. Up to now, significant progress has been made for the dendritic polymers in solving some of the fundamental and technical questions toward their theranostic applications. In this review, we briefly summarize how to control the structures of dendritic polymers, the theranostics-related properties derived from their structures and their theranostics-related applications. PMID:27217829

  12. Arsenic Exposure and Cell-Mediated Immunity in Pre-School Children in Rural Bangladesh

    PubMed Central

    Ahmed, Sultan; Moore, Sophie E.; Kippler, Maria; Gardner, Renee; Hawlader, M. D. H.; Wagatsuma, Yukiko; Raqib, Rubhana; Vahter, Marie

    2014-01-01

    Prenatal arsenic exposure has been associated with reduced thymic index and increased morbidity in infants, indicating arsenic-related impaired immune function. We aimed at elucidating potential effects of pre- and postnatal arsenic exposure on cell-mediated immune function in pre-school aged children. Children born in a prospective mother-child cohort in rural Bangladesh were followed up at 4.5 years of age (n = 577). Arsenic exposure was assessed by concentrations of arsenic metabolites (U-As) in child urine and maternal urine during pregnancy, using high-performance liquid chromatography online with inductively coupled plasma mass spectrometry. For assessment of delayed type hypersensitivity response, an intradermal injection of purified protein derivative (PPD) was given to Bacillus Calmette-Guerin vaccinated children. The diameter (mm) of induration was measured after 48–72 h. Plasma concentrations of 27 cytokines were analyzed by a multiplex cytokine assay. Children's concurrent, but not prenatal, arsenic exposure was associated with a weaker response to the injected PPD. The risk ratio (RR) of not responding to PPD (induration <5 mm) was 1.37 (95% confidence interval (CI): 1.07, 1.74) in children in the highest quartile of U-As (range 126–1228 μg/l), compared with the lowest (range 12–34 μg/l). The p for trend across the quartiles was 0.003. The association was stronger in undernourished children. Children's U-As in tertiles was inversely associated with two out of 27 cytokines only, i.e., IL-2 and TNF-α, both Th1 cytokines (in the highest tertile, regression coefficients (95% CI): −1.57 (−2.56, −0.57) and −4.53 (−8.62, −0.42), respectively), but not with Th2 cytokines. These associations were particularly strong in children with recent infections. In conclusion, elevated childhood arsenic exposure appeared to reduce cell-mediated immunity, possibly linked to reduced concentrations of Th1 cytokines. PMID:24924402

  13. Isothermal Dendritic Growth Experiment Video

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This video, captured during the Isothermal Dendritic Growth Experiment (IDGE) flown on STS-87 as a part of the fourth United States Microgravity payload, shows the growth of a dendrite, and the surface solidification that occurred on the front and back windows of the growth chamber. Dendrites are tiny, tree like structures that form as metals solidify.

  14. Dendritic Release of Neurotransmitters.

    PubMed

    Ludwig, Mike; Apps, David; Menzies, John; Patel, Jyoti C; Rice, Margaret E

    2016-12-06

    Release of neuroactive substances by exocytosis from dendrites is surprisingly widespread and is not confined to a particular class of transmitters: it occurs in multiple brain regions, and includes a range of neuropeptides, classical neurotransmitters, and signaling molecules, such as nitric oxide, carbon monoxide, ATP, and arachidonic acid. This review is focused on hypothalamic neuroendocrine cells that release vasopressin and oxytocin and midbrain neurons that release dopamine. For these two model systems, the stimuli, mechanisms, and physiological functions of dendritic release have been explored in greater detail than is yet available for other neurons and neuroactive substances. © 2017 American Physiological Society. Compr Physiol 7:235-252, 2017.

  15. Lithium Dendrite Formation

    SciTech Connect

    2015-03-06

    Scientists at the Department of Energy’s Oak Ridge National Laboratory have captured the first real-time nanoscale images of lithium dendrite structures known to degrade lithium-ion batteries. The ORNL team’s electron microscopy could help researchers address long-standing issues related to battery performance and safety. Video shows annular dark-field scanning transmission electron microscopy imaging (ADF STEM) of lithium dendrite nucleation and growth from a glassy carbon working electrode and within a 1.2M LiPF6 EC:DM battery electrolyte.

  16. Rat bladder cell-mediated mutagenesis of Chinese hamster V79 cells and metabolism of benzo(a)pyrene

    SciTech Connect

    Langenbach, R.; Malick, L.; Nesnow, S.

    1981-05-01

    Primary rat bladder epithelial cells were cocultivated with Chinese hamster V79 cells in the presence of carcinogens, and the induction of 6-thioguanine resistance in the V79 cells was used as a market of cell-mediated mutagenesis. The carcinogens dimethylnitrosamine, 7,12-dimethylbenz(a)anthracene, and benzo(a)pyrene (BP) were mutagenic to V79 cells in the presence of bladder cells but not in their absence. Analysis of BP metabolites (formed by bladder cells indicated that 7,8-dihydro-7,8-dihydroxybenzo(a)pyrene, 9,10-dihydro-9,10-dihydroxybenzo(a)pyrene, benzo(a)pyrene-3,6-quinone, and 9-hydroxybenzo(a)pyrene were the major organic-soluble metabolites formed. The finding that rat bladder peithelium can metabolize some carcinogens offers new possibilities for the mechanism of initiation of bladder cancer.

  17. Bystander cytotoxicity in human medullary thyroid carcinoma cells mediated by fusion yeast cytosine deaminase and 5-fluorocytosine.

    PubMed

    Kucerova, Lucia; Matuskova, Miroslava; Hlubinova, Kristina; Bohovic, Roman; Feketeova, Lucia; Janega, Pavol; Babal, Pavel; Poturnajova, Martina

    2011-12-01

    In our work, we have evaluated efficiency of gene-directed enzyme/prodrug therapy (GDEPT) based on combination of fusion yeast cytosine deaminase (yCD) and 5-fluorocytosine (5FC) on model human medullary thyroid carcinoma (MTC) cell line TT. We determined the efficiency of this GDEPT approach in suicide and bystander cytotoxicity induction. We have shown significant bystander effect in vitro and 5FC administration resulted in potent antitumor effect in vivo. Furthermore, we have unraveled high efficiency of cell-mediated GDEPT, when human mesenchymal stromal cells (MSC) were used as delivery vehicles in direct cocultures in vitro. Nevertheless, effector MSC exhibited inhibitory effect on TT cell proliferation and abrogated TT xenotransplant growth in vivo. We suggest that yCD/5FC combination represents another experimental treatment modality to be tested in MTC and our data further support the exploration of MSC antitumor potential for future use in metastatic MTC therapy.

  18. Diverse HLA-I Peptide Repertoires of the APC Lines MUTZ3-Derived Immature and Mature Dendritic Cells and THP1-Derived Macrophages.

    PubMed

    Nyambura, Lydon Wainaina; Jarmalavicius, Saulius; Baleeiro, Renato Brito; Walden, Peter

    2016-09-15

    Dendritic cells (DCs) and macrophages are specialized APCs that process and present self-Ags for induction of tolerance and foreign Ags to initiate T cell-mediated immunity. Related to differentiation states they have specific phenotypes and functions. However, the impact of these differentiations on Ag processing and presentation remains poorly defined. To gain insight into this, we analyzed and compared the HLA-I peptidomes of MUTZ3-derived human immature and mature DC lines and THP1-derived macrophages by liquid chromatography tandem mass spectrometry. We found that the HLA-I peptidomes were heterogeneous and individualized and were dominated by nonapeptides with similar HLA-I binding affinities and anchor residues. MUTZ3-derived DCs and THP1-derived macrophages were able to sample peptides from source proteins of almost all subcellular locations and were involved in various cellular functions in similar proportion, with preference to proteins involved in cell communication, signal transduction, protein metabolism, and transcription factor/regulator activity.

  19. A mixture of bacterial mechanical lysates is more efficient than single strain lysate and of bacterial-derived soluble products for the induction of an activating phenotype in human dendritic cells.

    PubMed

    Morandi, Barbara; Agazzi, Alessia; D'Agostino, Antonella; Antonini, Francesca; Costa, Gregorio; Sabatini, Federica; Ferlazzo, Guido; Melioli, Giovanni

    2011-07-01

    Dendritic cells (DCs), following an optimal maturation, are able to drive an efficient immune-response. For this, both co-stimulatory molecules (CD80 and CD86), activation molecules (CD83) and peptide presenting molecules (HLA) are over-expressed. The in vitro treatment of immature DC with fragments of bacterial strains, obtained by using a mechanical lysis as well as with bacterial-derived molecules (such as lipopolysaccharide and protido-glycan), induced the maturation of DCs and the secretion of a panel of cytokines and chemokines. Of note, ex vivo treated circulating DCs and plasmacytoid DCs were also activated by these bacterial bodies. However, while the particulate fraction of single bacterial strains or soluble bacterial-derived molecules induced a sub-optimal maturation (as evaluated by the expression of an activating phenotype on DCs and the amount of cytokine secretion), the addition of the mixture of the particulate fractions of the different bacterial strains was able to mediate an optimal maturation. These results were also confirmed by using the secretion of both cytokines and chemokines as markers of DC activation. All these findings suggest that the particulate fraction of bacterial lysate mixtures, because of their ability to interact with different surface structures, might be exploited not only as an immunogen, but also as an adjuvant treatment to boost an immune-response to poorly "antigenic" proteins, such as cancer antigens or allergens.

  20. Cell-mediated immunity to soluble and particulate inhaled antigens

    PubMed Central

    Hill, J. O.; Burrell, R.

    1979-01-01

    In order to determine the influence of an antigen's physical properties on the development of cell-mediated immunity (CMI) in the lung following aerosol immunization, human serum albumin (HSA) was prepared in either a soluble or a particulate form, the latter being coupled to respirable, carboxylated latex beads. Antigen was administered via an aerosol to groups of guinea-pigs, twice weekly for up to 4 weeks. Additional groups of animals served as unexposed and unconjugated latex controls. Lymphoid cells for CMI assays were isolated from the lung by bronchopulmonary lavage and from blood for use in mitogen- and antigen-induced lymphocyte transformation assays, as well as indirect macrophage migration inhibition tests. Particulate HSA-exposed animals yielded the highest numbers of free lung cells containing predominantly macrophages, with up to 33% lymphocytes. These were followed by the latex control, soluble HSA and unexposed control groups, respectively. Only the animals exposed to particulate HSA had evidence of antigen reactivation in the lung cell populations as measured by lymphocyte stimulation assays. In contrast, a response to polyclonal mitogens was found only in animals exposed to antigen in a soluble form. Data from macrophage depletion experiments suggest that the antigenicity of inhaled antigens may be due to the types and numbers of cells responding to the stimulus, and the subsequent role the alveolar macrophage may play in the modulation of cellular immunity. PMID:393444

  1. Lung Regeneration: Endogenous and Exogenous Stem Cell Mediated Therapeutic Approaches.

    PubMed

    Akram, Khondoker M; Patel, Neil; Spiteri, Monica A; Forsyth, Nicholas R

    2016-01-19

    The tissue turnover of unperturbed adult lung is remarkably slow. However, after injury or insult, a specialised group of facultative lung progenitors become activated to replenish damaged tissue through a reparative process called regeneration. Disruption in this process results in healing by fibrosis causing aberrant lung remodelling and organ dysfunction. Post-insult failure of regeneration leads to various incurable lung diseases including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Therefore, identification of true endogenous lung progenitors/stem cells, and their regenerative pathway are crucial for next-generation therapeutic development. Recent studies provide exciting and novel insights into postnatal lung development and post-injury lung regeneration by native lung progenitors. Furthermore, exogenous application of bone marrow stem cells, embryonic stem cells and inducible pluripotent stem cells (iPSC) show evidences of their regenerative capacity in the repair of injured and diseased lungs. With the advent of modern tissue engineering techniques, whole lung regeneration in the lab using de-cellularised tissue scaffold and stem cells is now becoming reality. In this review, we will highlight the advancement of our understanding in lung regeneration and development of stem cell mediated therapeutic strategies in combating incurable lung diseases.

  2. Suppression of Cell-Mediated Immunity in Experimental African Trypanosomiasis

    PubMed Central

    Mansfield, John M.; Wallace, John H.

    1974-01-01

    Adult New Zealand white rabbits were experimentally infected with a parasitic African hemoflagellate, Trypanosoma congolense, and were subsequently tested for in vivo and in vitro aspects of cell-mediated immune function. Chronically infected rabbits were sensitized to mycobacterial protein and skin-tested with purified protein derivative; all infected animals demonstrated much milder skin-test responses to antigen than control groups. Similarly, peripheral blood lymphocyte responses in vitro to purified protein derivative and, as well, to phytohemagglutinin were markedly suppressed. Supernatant fluids of antigen-stimulated lymph node cell cultures from T. congolense-infected rabbits failed to demonstrate migration inhibitory factor activity but did possess normal levels of blastogenic factor activity. An active infection was necessary for demonstration of suppressed immune responses, and components present in infected rabbit serum were apparently not responsible for the observed abnormalities. Suppression of T-lymphocyte subpopulations may well explain the occurrence of numerous immunological aberrations arising during human and animal infections with the African trypanosomes. PMID:4854532

  3. Lung Regeneration: Endogenous and Exogenous Stem Cell Mediated Therapeutic Approaches

    PubMed Central

    Akram, Khondoker M.; Patel, Neil; Spiteri, Monica A.; Forsyth, Nicholas R.

    2016-01-01

    The tissue turnover of unperturbed adult lung is remarkably slow. However, after injury or insult, a specialised group of facultative lung progenitors become activated to replenish damaged tissue through a reparative process called regeneration. Disruption in this process results in healing by fibrosis causing aberrant lung remodelling and organ dysfunction. Post-insult failure of regeneration leads to various incurable lung diseases including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Therefore, identification of true endogenous lung progenitors/stem cells, and their regenerative pathway are crucial for next-generation therapeutic development. Recent studies provide exciting and novel insights into postnatal lung development and post-injury lung regeneration by native lung progenitors. Furthermore, exogenous application of bone marrow stem cells, embryonic stem cells and inducible pluripotent stem cells (iPSC) show evidences of their regenerative capacity in the repair of injured and diseased lungs. With the advent of modern tissue engineering techniques, whole lung regeneration in the lab using de-cellularised tissue scaffold and stem cells is now becoming reality. In this review, we will highlight the advancement of our understanding in lung regeneration and development of stem cell mediated therapeutic strategies in combating incurable lung diseases. PMID:26797607

  4. CXCR5+ T helper cells mediate protective immunity against tuberculosis

    PubMed Central

    Slight, Samantha R.; Rangel-Moreno, Javier; Gopal, Radha; Lin, Yinyao; Fallert Junecko, Beth A.; Mehra, Smriti; Selman, Moises; Becerril-Villanueva, Enrique; Baquera-Heredia, Javier; Pavon, Lenin; Kaushal, Deepak; Reinhart, Todd A.; Randall, Troy D.; Khader, Shabaana A.

    2013-01-01

    One third of the world’s population is infected with Mycobacterium tuberculosis (Mtb). Although most infected people remain asymptomatic, they have a 10% lifetime risk of developing active tuberculosis (TB). Thus, the current challenge is to identify immune parameters that distinguish individuals with latent TB from those with active TB. Using human and experimental models of Mtb infection, we demonstrated that organized ectopic lymphoid structures containing CXCR5+ T cells were present in Mtb-infected lungs. In addition, we found that in experimental Mtb infection models, the presence of CXCR5+ T cells within ectopic lymphoid structures was associated with immune control. Furthermore, in a mouse model of Mtb infection, we showed that activated CD4+CXCR5+ T cells accumulated in Mtb-infected lungs and produced proinflammatory cytokines. Mice deficient in Cxcr5 had increased susceptibility to TB due to defective T cell localization within the lung parenchyma. We demonstrated that CXCR5 expression in T cells mediated correct T cell localization within TB granulomas, promoted efficient macrophage activation, protected against Mtb infection, and facilitated lymphoid follicle formation. These data demonstrate that CD4+CXCR5+ T cells play a protective role in the immune response against TB and highlight their potential use for future TB vaccine design and therapy. PMID:23281399

  5. Natural killer cell mediated cytotoxic responses in the Tasmanian devil.

    PubMed

    Brown, Gabriella K; Kreiss, Alexandre; Lyons, A Bruce; Woods, Gregory M

    2011-01-01

    The Tasmanian devil (Sarcophilus harrisii), the world's largest marsupial carnivore, is under threat of extinction following the emergence of an infectious cancer. Devil facial tumour disease (DFTD) is spread between Tasmanian devils during biting. The disease is consistently fatal and devils succumb without developing a protective immune response. The aim of this study was to determine if Tasmanian devils were capable of forming cytotoxic antitumour responses and develop antibodies against DFTD cells and foreign tumour cells. The two Tasmanian devils immunised with irradiated DFTD cells did not form cytotoxic or humoral responses against DFTD cells, even after multiple immunisations. However, following immunisation with xenogenic K562 cells, devils did produce cytotoxic responses and antibodies against this foreign tumour cell line. The cytotoxicity appeared to occur through the activity of natural killer (NK) cells in an antibody dependent manner. Classical NK cell responses, such as innate killing of DFTD and foreign cancer cells, were not observed. Cells with an NK-like phenotype comprised approximately 4 percent of peripheral blood mononuclear cells. The results of this study suggest that Tasmanian devils have NK cells with functional cytotoxic pathways. Although devil NK cells do not directly recognise DFTD cancer cells, the development of antibody dependent cell-mediated cytotoxicity presents a potential pathway to induce cytotoxic responses against the disease. These findings have positive implications for future DFTD vaccine research.

  6. Mast cell mediators and peritoneal adhesion formation in the rat.

    PubMed

    Langer, J C; Liebman, S M; Monk, P K; Pelletier, G J

    1995-09-01

    We have previously shown that mast cell stabilization attenuates peritoneal adhesion formation in the rat. The present study investigated the mechanism of this protection. Adhesions were created in weanling rats using cecal scraping and application of 95% ethanol. Rats received specific blockers for the mast cell products histamine, serotonin (5HT), leukotriene D4, and platelet activating factor intraperitoneally 30 min before laparotomy and at the time of abdominal closure. Control animals received saline. Adhesions were assessed blindly 1 week later using a standardized scale. Adhesion formation was not affected by histamine blockade using combined mepyramine and ranitidine, 5-HT1 blockade using methysergide, 5-HT3 blockade using ondansetron, leukotriene D4 blockade using MK-571, or platelet activating factor blockade using WEB-2086. However, blockade of the 5-HT2 receptor using ketanserin resulted in significant dose-dependent attenuation of adhesions compared to saline. These data suggest that mast cells mediate peritoneal adhesion formation in the rat through release of serotonin acting on 5HT2 receptors. Further understanding of this process may lead to new strategies for the prevention of postoperative adhesions.

  7. Molecular mechanisms of dendrite morphogenesis

    PubMed Central

    Arikkath, Jyothi

    2012-01-01

    Dendrites are key integrators of synaptic information in neurons and play vital roles in neuronal plasticity. Hence, it is necessary that dendrite arborization is precisely controlled and coordinated with synaptic activity to ensure appropriate functional neural network integrity. In the past several years, it has become increasingly clear that several cell intrinsic and extrinsic mechanisms contribute to dendritic arborization. In this review, we will discuss some of the molecular mechanisms that regulate dendrite morphogenesis, particularly in cortical and hippocampal pyramidal neurons and some of the implications of aberrant dendritic morphology for human disease. Finally, we will discuss the current challenges and future directions in the field. PMID:23293584

  8. Transport Processes in Dendritic Crystallization

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.

    1984-01-01

    Free dentritic growth refers to the unconstrained development of crystals within a supercooled melt, which is the classical dendrite problem. The development of theoretical understanding of dendritic growth and its experimental status is sketched showing that transport theory and interfacial thermodynamics (capillarity theory) are insufficient ingredients to develop a truly predictive model of dendrite formation. The convenient, but incorrect, notion of maximum velocity was used for many years to estimate the behavior of dendritic transformations until supplanted by modern dynamic stability theory. The proper combinations of transport theory and morphological stability seem to be able to predict the salient aspects of dendritic growth, especially in the neighborhood of the tip.

  9. Modification of dendritic development.

    PubMed

    Feria-Velasco, Alfredo; del Angel, Alma Rosa; Gonzalez-Burgos, Ignacio

    2002-01-01

    Since 1890 Ramón y Cajal strongly defended the theory that dendrites and their processes and spines had a function of not just nutrient transport to the cell body, but they had an important conductive role in neural impulse transmission. He extensively discussed and supported this theory in the Volume 1 of his extraordinary book Textura del Sistema Nervioso del Hombre y de los Vertebrados. Also, Don Santiago significantly contributed to a detailed description of the various neural components of the hippocampus and cerebral cortex during development. Extensive investigation has been done in the last Century related to the functional role of these complex brain regions, and their association with learning, memory and some limbic functions. Likewise, the organization and expression of neuropsychological qualities such as memory, exploratory behavior and spatial orientation, among others, depend on the integrity and adequate functional activity of the cerebral cortex and hippocampus. It is known that brain serotonin synthesis and release depend directly and proportionally on the availability of its precursor, tryptophan (TRY). By using a chronic TRY restriction model in rats, we studied their place learning ability in correlation with the dendritic spine density of pyramidal neurons in field CA1 of the hippocampus during postnatal development. We have also reported alterations in the maturation pattern of the ability for spontaneous alternation and task performance evaluating short-term memory, as well as adverse effects on the density of dendritic spines of hippocampal CA1 field pyramidal neurons and on the dendritic arborization and the number of dendritic spines of pyramidal neurons from the third layer of the prefrontal cortex using the same model of TRY restriction. The findings obtained in these studies employing a modified Golgi method, can be interpreted as a trans-synaptic plastic response due to understimulation of serotoninergic receptors located in the

  10. Tissue requirements for establishing long-term CD4+ T cell-mediated immunity following Leishmania donovani infection.

    PubMed

    Bunn, Patrick T; Stanley, Amanda C; de Labastida Rivera, Fabian; Mulherin, Alexander; Sheel, Meru; Alexander, Clare E; Faleiro, Rebecca J; Amante, Fiona H; Montes De Oca, Marcela; Best, Shannon E; James, Kylie R; Kaye, Paul M; Haque, Ashraful; Engwerda, Christian R

    2014-04-15

    Organ-specific immunity is a feature of many infectious diseases, including visceral leishmaniasis caused by Leishmania donovani. Experimental visceral leishmaniasis in genetically susceptible mice is characterized by an acute, resolving infection in the liver and chronic infection in the spleen. CD4+ T cell responses are critical for the establishment and maintenance of hepatic immunity in this disease model, but their role in chronically infected spleens remains unclear. In this study, we show that dendritic cells are critical for CD4+ T cell activation and expansion in all tissue sites examined. We found that FTY720-mediated blockade of T cell trafficking early in infection prevented Ag-specific CD4+ T cells from appearing in lymph nodes, but not the spleen and liver, suggesting that early CD4+ T cell priming does not occur in liver-draining lymph nodes. Extended treatment with FTY720 over the first month of infection increased parasite burdens, although this associated with blockade of lymphocyte egress from secondary lymphoid tissue, as well as with more generalized splenic lymphopenia. Importantly, we demonstrate that CD4+ T cells are required for the establishment and maintenance of antiparasitic immunity in the liver, as well as for immune surveillance and suppression of parasite outgrowth in chronically infected spleens. Finally, although early CD4+ T cell priming appeared to occur most effectively in the spleen, we unexpectedly revealed that protective CD4+ T cell-mediated hepatic immunity could be generated in the complete absence of all secondary lymphoid tissues.

  11. Engineering nanomaterials to address cell-mediated inflammation in atherosclerosis

    PubMed Central

    Allen, Sean; Liu, Yu-Gang; Scott, Evan

    2016-01-01

    Atherosclerosis is an inflammatory disorder with a pathophysiology driven by both innate and adaptive immunity and a primary cause of cardiovascular disease (CVD) worldwide. Vascular inflammation and accumulation of foam cells and their products induce maturation of atheromas, or plaques, which can rupture by metalloprotease action, leading to ischemic stroke or myocardial infarction. Diverse immune cell populations participate in all stages of plaque maturation, many of which directly influence plaque stability and rupture via inflammatory mechanisms. Current clinical treatments for atherosclerosis focus on lowering serum levels of low-density lipoprotein (LDL) using therapeutics such as statins, administration of antithrombotic drugs, and surgical intervention. Strategies that address cell-mediated inflammation are lacking, and consequently have recently become an area of considerable research focus. Nanomaterials have emerged as highly advantageous tools for these studies, as they can be engineered to target specific inflammatory cell populations, deliver therapeutics of wide-ranging solubilities and enhance analytical methods that include imaging and proteomics. Furthermore, the highly phagocytic nature of antigen presenting cells (APCs), a diverse cell population central to the initiation of immune responses and inflammation, make them particularly amenable to targeting and modulation by nanoscale particulates. Nanomaterials have therefore become essential components of vaccine formulations and treatments for inflammation-driven pathologies like autoimmunity, and present novel opportunities for immunotherapeutic treatments of CVD. Here, we review recent progress in the design and use of nanomaterials for therapeutic assessment and treatment of atherosclerosis. We will focus on promising new approaches that utilize nanomaterials for cell-specific imaging, gene therapy and immunomodulation. PMID:27135051

  12. Normal dendrite growth in Drosophila motor neurons requires the AP-1 transcription factor.

    PubMed

    Hartwig, Cortnie L; Worrell, Jason; Levine, Richard B; Ramaswami, Mani; Sanyal, Subhabrata

    2008-09-01

    During learning and memory formation, information flow through networks is regulated significantly through structural alterations in neurons. Dendrites, sites of signal integration, are key targets of activity-mediated modifications. Although local mechanisms of dendritic growth ensure synapse-specific changes, global mechanisms linking neural activity to nuclear gene expression may have profound influences on neural function. Fos, being an immediate-early gene, is ideally suited to be an initial transducer of neural activity, but a precise role for the AP-1 transcription factor in dendrite growth remains to be elucidated. Here we measure changes in the dendritic fields of identified Drosophila motor neurons in vivo and in primary culture to investigate the role of the immediate-early transcription factor AP-1 in regulating endogenous and activity-induced dendrite growth. Our data indicate that (a) increased neural excitability or depolarization stimulates dendrite growth, (b) AP-1 (a Fos, Jun hetero-dimer) is required for normal motor neuron dendritic growth during development and in response to activity induction, and (c) neuronal Fos protein levels are rapidly but transiently induced in motor neurons following neural activity. Taken together, these results show that AP-1 mediated transcription is important for dendrite growth, and that neural activity influences global dendritic growth through a gene-expression dependent mechanism gated by AP-1.

  13. Cell-Mediated Immunity and Its Role in Resistance to Infection

    PubMed Central

    Wing, Edward J.; Remington, Jack S.

    1977-01-01

    The recently acquired knowledge of the importance of cell-mediated immunity in many illnesses and the discovery of a variety of substances that can restore certain cell-mediated immune functions has served to focus the attention of physicians on this area of immunity. It is important for practicing physicians to have a clear understanding of current knowledge of the role of cell-mediated immunity in resistance to infection and how this arm of the immune system relates to the diagnosis and therapy of infectious diseases. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5. PMID:318786

  14. Dendritic Spikes in Sensory Perception

    PubMed Central

    Manita, Satoshi; Miyakawa, Hiroyoshi; Kitamura, Kazuo; Murayama, Masanori

    2017-01-01

    What is the function of dendritic spikes? One might argue that they provide conditions for neuronal plasticity or that they are essential for neural computation. However, despite a long history of dendritic research, the physiological relevance of dendritic spikes in brain function remains unknown. This could stem from the fact that most studies on dendrites have been performed in vitro. Fortunately, the emergence of novel techniques such as improved two-photon microscopy, genetically encoded calcium indicators (GECIs), and optogenetic tools has provided the means for vital breakthroughs in in vivo dendritic research. These technologies enable the investigation of the functions of dendritic spikes in behaving animals, and thus, help uncover the causal relationship between dendritic spikes, and sensory information processing and synaptic plasticity. Understanding the roles of dendritic spikes in brain function would provide mechanistic insight into the relationship between the brain and the mind. In this review article, we summarize the results of studies on dendritic spikes from a historical perspective and discuss the recent advances in our understanding of the role of dendritic spikes in sensory perception. PMID:28261060

  15. The Spread of Ras Activity Triggered by Activation of a Single Dendritic Spine

    PubMed Central

    Harvey, Christopher D.; Yasuda, Ryohei; Zhong, Haining; Svoboda, Karel

    2009-01-01

    In neurons, individual dendritic spines isolate NMDA receptor-mediated Ca2+ accumulations from the dendrite and other spines. However, it is not known to what extent spines compartmentalize signaling events downstream of Ca2+ influx. We combined two-photon fluorescence lifetime imaging (FLIM) with two-photon glutamate uncaging to image the activity of the small GTPase Ras following NMDA receptor activation at individual spines. Induction of long-term potentiation (LTP) triggered robust Ca2+-dependent Ras activation in single spines that decayed in approximately 5 minutes. Ras activity spread over approximately 10 micrometers of dendrite and invaded neighboring spines by diffusion. The spread of Ras-dependent signaling was necessary for the local regulation of the threshold for LTP induction. Thus Ca2+-dependent synaptic signals can spread to couple multiple synapses on short stretches of dendrite. PMID:18556515

  16. Silicon dendritic web material

    NASA Technical Reports Server (NTRS)

    Meier, D. L.; Campbell, R. B.; Sienkiewicz, L. J.; Rai-Choudhury, P.

    1982-01-01

    The development of a low cost and reliable contact system for solar cells and the fabrication of several solar cell modules using ultrasonic bonding for the interconnection of cells and ethylene vinyl acetate as the potting material for module encapsulation are examined. The cells in the modules were made from dendritic web silicon. To reduce cost, the electroplated layer of silver was replaced with an electroplated layer of copper. The modules that were fabricated used the evaporated Ti, Pd, Ag and electroplated Cu (TiPdAg/Cu) system. Adherence of Ni to Si is improved if a nickel silicide can be formed by heat treatment. The effectiveness of Ni as a diffusion barrier to Cu and the ease with which nickel silicide is formed is discussed. The fabrication of three modules using dendritic web silicon and employing ultrasonic bonding for interconnecting calls and ethylene vinyl acetate as the potting material is examined.

  17. Magnetic and dendritic catalysts.

    PubMed

    Wang, Dong; Deraedt, Christophe; Ruiz, Jaime; Astruc, Didier

    2015-07-21

    The recovery and reuse of catalysts is a major challenge in the development of sustainable chemical processes. Two methods at the frontier between homogeneous and heterogeneous catalysis have recently emerged for addressing this problem: loading the catalyst onto a dendrimer or onto a magnetic nanoparticle. In this Account, we describe representative examples of these two methods, primarily from our research group, and compare them. We then describe new chemistry that combines the benefits of these two methods of catalysis. Classic dendritic catalysis has involved either attaching the catalyst covalently at the branch termini or within the dendrimer core. We have used chelating pyridyltriazole ligands to insolubilize catalysts at the termini of dendrimers, providing an efficient, recyclable heterogeneous catalysts. With the addition of dendritic unimolecular micelles olefin metathesis reactions catalyzed by commercial Grubbs-type ruthenium-benzylidene complexes in water required unusually low amounts of catalyst. When such dendritic micelles include intradendritic ligands, both the micellar effect and ligand acceleration promote faster catalysis in water. With these types of catalysts, we could carry out azide alkyne cycloaddition ("click") chemistry with only ppm amounts of CuSO4·5H2O and sodium ascorbate under ambient conditions. Alternatively we can attach catalysts to the surface of superparamagnetic iron oxide nanoparticles (SPIONs), essentially magnetite (Fe3O4) or maghemite (γ-Fe2O3), offering the opportunity to recover the catalysts using magnets. Taking advantage of the merits of both of these strategies, we and others have developed a new generation of recyclable catalysts: dendritic magnetically recoverable catalysts. In particular, some of our catalysts with a γ-Fe2O3@SiO2 core and 1,2,3-triazole tethers and loaded with Pd nanoparticles generate strong positive dendritic effects with respect to ligand loading, catalyst loading, catalytic activity and

  18. Selective dendritic susceptibility to bioenergetic, excitotoxic and redox perturbations in cortical neurons☆

    PubMed Central

    Hasel, Philip; Mckay, Sean; Qiu, Jing; Hardingham, Giles E.

    2015-01-01

    Neurodegenerative and neurological disorders are often characterised by pathological changes to dendrites, in advance of neuronal death. Oxidative stress, energy deficits and excitotoxicity are implicated in many such disorders, suggesting a potential vulnerability of dendrites to these situations. Here we have studied dendritic vs. somatic responses of primary cortical neurons to these types of challenges in real-time. Using a genetically encoded indicator of intracellular redox potential (Grx1-roGFP2) we found that, compared to the soma, dendritic regions exhibited more dramatic fluctuations in redox potential in response to sub-lethal ROS exposure, and existed in a basally more oxidised state. We also studied the responses of dendritic and somatic regions to excitotoxic NMDA receptor activity. Both dendritic and somatic regions experienced similar increases in cytoplasmic Ca2+. Interestingly, while mitochondrial Ca2+ uptake and initial mitochondrial depolarisation were similar in both regions, secondary delayed mitochondrial depolarisation was far weaker in dendrites, potentially as a result of less NADH depletion. Despite this, ATP levels were found to fall faster in dendritic regions. Finally we studied the responses of dendritic and somatic regions to energetically demanding action potential burst activity. Burst activity triggered PDH dephosphorylation, increases in oxygen consumption and cellular NADH:NAD ratio. Compared to somatic regions, dendritic regions exhibited a smaller degree of mitochondrial Ca2+ uptake, lower fold-induction of NADH and larger reduction in ATP levels. Collectively, these data reveal that dendritic regions of primary neurons are vulnerable to greater energetic and redox fluctuations than the cell body, which may contribute to disease-associated dendritic damage. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. PMID:25541281

  19. Dendritic cells: sentinels of immunity and tolerance.

    PubMed

    Kubach, Jan; Becker, Christian; Schmitt, Edgar; Steinbrink, Kerstin; Huter, Eva; Tuettenberg, Andrea; Jonuleit, Helmut

    2005-04-01

    The induction of effective antigen-specific T-cell immunity to pathogens without the initiation of autoimmunity has evolved as a sophisticated and highly balanced immunoregulatory mechanism. This mechanism assures the generation of antigen-specific effector cells as well as the induction and maintenance of antigen-specific tolerance to self-structures of the body. As professional antigen-presenting cells of the immune system, dendritic cells (DC) are ideally positioned throughout the entire body and equipped with a unique capability to transport antigens from the periphery to lymphoid tissues. There is growing evidence that DC, besides their well-known immunostimulatory properties, also induce and regulate T-cell tolerance in the periphery. This regulatory function of DC is strictly dependent on their different stages of maturation and activation. Additionally, immunosuppressive agents and cytokines further influence the functions of maturing DC. The regulatory properties of DC include induction of T-cell anergy, apoptosis, and the generation of T-cells with regulatory capacities. This brief review summarizes the current knowledge about the immunoregulatory role of DC as guardians for the induction of T-cell immunity and tolerance.

  20. Dendritic Materials Systems

    DTIC Science & Technology

    2003-09-22

    2-hydroxyethyl)-e-caprolactone,” Macromolecules, 32, 6881-4, (1999). Yu, D.; Vladimirov, N.; Fréchet, J.M.J. “ MALDI - TOF in the Characterization of...Mat Sci. Eng., (1999). Yu, D.; Vladimirov, N.; Fréchet, J. M. J. “ MALDI - TOF Mass Spectrometry in the Characterization of Dendritic-Linear Block and...with long endgroups capable of chain entanglements providing uniform continuous films. We found that the surface properties of polyetherimide ( PEI

  1. Web-dendritic ribbon growth

    NASA Technical Reports Server (NTRS)

    Hilborn, R. B., Jr.; Faust, J. W., Jr.

    1976-01-01

    A web furnace was constructed for pulling dendritic-web samples. The effect of changes in the furnace thermal geometry on the growth of dendritic-web was studied. Several attempts were made to grow primitive dendrites for use as the dendritic seed crystals for web growth and to determine the optimum twin spacing in the dendritic seed crystal for web growth. Mathematical models and computer programs were used to determine the thermal geometries in the susceptor, crucible melt, meniscus, and web. Several geometries were determined for particular furnace geometries and growth conditions. The information obtained was used in conjunction with results from the experimental growth investigations in order to achieve proper conditions for sustained pulling of two dendrite web ribbons. In addition, the facilities for obtaining the following data were constructed: twin spacing, dislocation density, web geometry, resistivity, majority charge carrier type, and minority carrier lifetime.

  2. Micronutrient supplementation and T-cell mediated immune responses in patients with tuberculosis in Tanzania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited studies exist regarding whether incorporating micronutrient supplements during tuberculosis (TB) treatment may improve cell-mediated immune response. We examine the effect of micronutrient supplementation on lymphocyte proliferation response to mycobacteria or T cell mitogens in a randomize...

  3. IDGE: Isothermal Dendritic Growth Experiment

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Isothermal Dendritic Growth Experiment (IDGE) flew on STS-62 to study the microscopic, tree-like structures (dendrites) that form within metals as they solidify from molten materials. The size, shape, and orientation of these dendrites affect the strength and usefulness of metals. Data from this experiment will be used to test and improve the mathematical models that support the industrial production of metals.

  4. Selective and efficient generation of functional Batf3-dependent CD103+ dendritic cells from mouse bone marrow.

    PubMed

    Mayer, Christian Thomas; Ghorbani, Peyman; Nandan, Amrita; Dudek, Markus; Arnold-Schrauf, Catharina; Hesse, Christina; Berod, Luciana; Stüve, Philipp; Puttur, Franz; Merad, Miriam; Sparwasser, Tim

    2014-11-13

    Multiple subsets of FMS-like tyrosine kinase 3 ligand (FLT3L)-dependent dendritic cells (DCs) control T-cell tolerance and immunity. In mice, Batf3-dependent CD103(+) DCs efficiently enter lymph nodes and cross-present antigens, rendering this conserved DC subset a promising target for tolerance induction or vaccination. However, only limited numbers of CD103(+) DCs can be isolated with current methods. Established bone marrow culture protocols efficiently generate monocyte-derived DCs or produce a mixture of FLT3L-dependent DC subsets. We show that CD103(+) DC development requires prolonged culture time and continuous action of both FLT3L and granulocyte macrophage colony-stimulating factor (GM-CSF), explained by a dual effect of GM-CSF on DC precursors and differentiating CD103(+) DCs. Accordingly, we established a novel method to generate large numbers of CD103(+) DCs (iCD103-DCs) with limited presence of other DC subsets. iCD103-DCs develop in a Batf3- and Irf8-dependent fashion, express a CD8α/CD103 DC gene signature, cross-present cell-associated antigens, and respond to TLR3 stimulation. Thus, iCD103-DCs reflect key features of tissue CD103(+) DCs. Importantly, iCD103-DCs express high levels of CCR7 upon maturation and migrate to lymph nodes more efficiently than classical monocyte-derived DCs. Finally, iCD103-DCs induce T cell-mediated protective immunity in vivo. Our study provides insights into CD103(+) DC development and function.

  5. Oral administration of paeoniflorin attenuates allergic contact dermatitis by inhibiting dendritic cell migration and Th1 and Th17 differentiation in a mouse model.

    PubMed

    Shi, Dongmei; Li, Xuefeng; Li, Dongmei; Zhao, Quanjing; Shen, Yongnian; Yan, Hongxia; Fu, Hongjun; Zheng, Hailin; Lu, Guixia; Qiu, Ying; Liu, Weida

    2015-04-01

    Allergic contact dermatitis (ACD) is a hapten-specific CD4(+) T-cells mediated inflammatory response of the skin. Its pathomechanism involves 2 phases, an induction phase and an elicitation phase. Langerhans cells (LCs) and dendritic cells (DCs) in the skin play key roles in presenting low molecular weight chemicals (haptens) to the lymph nodes. Therefore, inhibition of the migration of LCs or DCs and T-cell proliferation is each expected to control ACD disease. To explore the effectiveness of paeoniflorin (PF) on the migration of LCs and T-cell proliferation in vivo, we establish a murine model of ACD, promoted by repeated exposure to an allergen (specifically 1-Chloro-2,4-dinitrobenzene (DNCB)). Administration of PF inhibits DC migration in this DNCB-induced model in the induction phase. As a result, epidermal LC density in the elicitation phase increased in PF-treated mice when compared to PF-untreated mice. At the same time, PF reduced IFN-γ(+)CD4(+) and IL-17(+)CD4(+) T cells proliferation (but not IL-4(+)CD4(+) T cells proliferation), leading to an attenuated cutaneous inflammatory response. Consistent with this T-cell proliferation profile, secretions of IFN-γ and IL-17 were reduced and IL-10 secretion increased in PF-treated mice, but production of IL-4 and IL-5 remained unchanged in the skin and blood samples. These results suggest that oral administration of PF can treat and prevent ACD effectively through inhibition of DC migration, and thus decrease the capacity of DCs to stimulate Th1 and Th17 cell differentiation and cytokine production.

  6. TLR4-mediated podosome loss discriminates gram-negative from gram-positive bacteria in their capacity to induce dendritic cell migration and maturation.

    PubMed

    van Helden, Suzanne F G; van den Dries, Koen; Oud, Machteld M; Raymakers, Reinier A P; Netea, Mihai G; van Leeuwen, Frank N; Figdor, Carl G

    2010-02-01

    Chronic infections are caused by microorganisms that display effective immune evasion mechanisms. Dendritic cell (DC)-dependent T cell-mediated adaptive immunity is one of the mechanisms that have evolved to prevent the occurrence of chronic bacterial infections. In turn, bacterial pathogens have developed strategies to evade immune recognition. In this study, we show that gram-negative and gram-positive bacteria differ in their ability to activate DCs and that gram-negative bacteria are far more effective inducers of DC maturation. Moreover, we observed that only gram-negative bacteria can induce loss of adhesive podosome structures in DCs, a response necessary for the induction of effective DC migration. We demonstrate that the ability of gram-negative bacteria to trigger podosome turnover and induce DC migration reflects their capacity to selectively activate TLR4. Examining mice defective in TLR4 signaling, we show that this DC maturation and migration are mainly Toll/IL-1 receptor domain-containing adaptor-inducing IFNbeta-dependent. Furthermore, we show that these processes depend on the production of PGs by these DCs, suggesting a direct link between TLR4-mediated signaling and arachidonic metabolism. These findings demonstrate that gram-positive and gram-negative bacteria profoundly differ in their capacity to activate DCs. We propose that this inability of gram-positive bacteria to induce DC maturation and migration is part of the armamentarium necessary for avoiding the induction of an effective cellular immune response and may explain the frequent involvement of these pathogens in chronic infections.

  7. Self-Antigen Presentation by Dendritic Cells in Autoimmunity

    PubMed Central

    Hopp, Ann-Katrin; Rupp, Anne; Lukacs-Kornek, Veronika

    2014-01-01

    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. PMID:24592266

  8. Dendritic K+ channels contribute to spike-timing dependent long-term potentiation in hippocampal pyramidal neurons

    PubMed Central

    Watanabe, Shigeo; Hoffman, Dax A.; Migliore, Michele; Johnston, Daniel

    2002-01-01

    We investigated the role of A-type K+ channels for the induction of long-term potentiation (LTP) of Schaffer collateral inputs to hippocampal CA1 pyramidal neurons. When low-amplitude excitatory postsynaptic potentials (EPSPs) were paired with two postsynaptic action potentials in a theta-burst pattern, N-methyl-d-aspartate (NMDA)-receptor-dependent LTP was induced. The amplitudes of the back-propagating action potentials were boosted in the dendrites only when they were coincident with the EPSPs. Mitogen-activated protein kinase (MAPK) inhibitors PD 098059 or U0126 shifted the activation of dendritic K+ channels to more hyperpolarized potentials, reduced the boosting of dendritic action potentials by EPSPs, and suppressed the induction of LTP. These results support the hypothesis that dendritic K+ channels and the boosting of back-propagating action potentials contribute to the induction of LTP in CA1 neurons. PMID:12048251

  9. Targeting Dendritic Cells in vivo for Cancer Therapy

    PubMed Central

    Caminschi, Irina; Maraskovsky, Eugene; Heath, William Ross

    2012-01-01

    Monoclonal antibodies that recognize cell surface molecules have been used deliver antigenic cargo to dendritic cells (DC) for induction of immune responses. The encouraging anti-tumor immunity elicited using this immunization strategy suggests its suitability for clinical trials. This review discusses the complex network of DC, the functional specialization 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-tumor CD4 and CD8 T cell responses that can recognize tumor-specific antigens. Finally, we review preclinical experiments and the progress toward targeting human DC in vivo. PMID:22566899

  10. Double-bromo and extraterminal (BET) domain proteins regulate dendrite morphology and mechanosensory function

    PubMed Central

    Bagley, Joshua A.; Yan, Zhiqiang; Zhang, Wei; Wildonger, Jill

    2014-01-01

    A complex array of genetic factors regulates neuronal dendrite morphology. Epigenetic regulation of gene expression represents a plausible mechanism to control pathways responsible for specific dendritic arbor shapes. By studying the Drosophila dendritic arborization (da) neurons, we discovered a role of the double-bromodomain and extraterminal (BET) family proteins in regulating dendrite arbor complexity. A loss-of-function mutation in the single Drosophila BET protein encoded by female sterile 1 homeotic [fs(1)h] causes loss of fine, terminal dendritic branches. Moreover, fs(1)h is necessary for the induction of branching caused by a previously identified transcription factor, Cut (Ct), which regulates subtype-specific dendrite morphology. Finally, disrupting fs(1)h function impairs the mechanosensory response of class III da sensory neurons without compromising the expression of the ion channel NompC, which mediates the mechanosensitive response. Thus, our results identify a novel role for BET family proteins in regulating dendrite morphology and a possible separation of developmental pathways specifying neural cell morphology and ion channel expression. Since the BET proteins are known to bind acetylated histone tails, these results also suggest a role of epigenetic histone modifications and the “histone code,” in regulating dendrite morphology. PMID:25184680

  11. Developing dendrites demonstrate unexpected specificity.

    PubMed

    Chalupa, Leo M

    2006-11-22

    Our knowledge of how developing dendrites attain their mature state is still rudimentary. In this issue of Neuron, Mumm et al. rely on time-lapsed analysis of ingrowing dendrites of retinal ganglion cells in transgenic zebrafish to show that this process is much more specific than has been suspected.

  12. Maturation-Resistant Dendritic Cells Ameliorate Experimental Autoimmune Uveoretinitis

    PubMed Central

    Oh, Keunhee; Kim, Yon Su

    2011-01-01

    Background Endogenous uveitis is a chronic inflammatory eye disease of human, which frequently leads to blindness. Experimental autoimmune uveoretinitis (EAU) is an animal disease model of human endogenous uveitis and can be induced in susceptible animals by immunization with retinal antigens. EAU resembles the key immunological characteristics of human disease in that both are CD4+ T-cell mediated diseases. Dendritic cells (DCs) are specialized antigen-presenting cells that are uniquely capable of activating naïve T cells. Regulation of immune responses through modulation of DCs has thus been tried extensively. Recently our group reported that donor strain-derived immature DC pretreatment successfully controlled the adverse immune response during allogeneic transplantation. Methods EAU was induced by immunization with human interphotoreceptor retinoid-binding protein (IRBP) peptide1-20. Dendritic cells were differentiated from bone marrow in the presence of recombinant GM-CSF. Results In this study, we used paraformaldehyde-fixed bone marrow-derived DCs to maintain them in an immature state. Pretreatment with fixed immature DCs, but not fixed mature DCs, ameliorated the disease progression of EAU by inhibiting uveitogenic CD4+ T cell activation and differentiation. Conclusion Application of iBMDC prepared according to the protocol of this study would provide an important treatment modality for the autoimmune diseases and transplantation rejection. PMID:22346781

  13. New generation of dendritic cell vaccines.

    PubMed

    Radford, Kristen J; Caminschi, Irina

    2013-02-01

    Dendritic cells (DC) play a pivotal role in the induction and regulation of immune responses, including the induction of cytotoxic T lymphocytes (CTL) responses. These are essential for the eradication of cancers and pathogens including HIV and malaria, for which there are currently no effective vaccines. New developments in our understanding of DC biology have identified the key DC subset responsible for CTL induction, which is now an attractive candidate to target for vaccination. These DC are characterized by expression of novel markers Clec9A and XCR1, and a specialized capacity to cross-present antigen (Ag) from tumors and pathogens that do not directly infect DC. New generation DC vaccines that specifically target the cross-presenting DC in vivo have already demonstrated potential in preclinical animal models but the challenge remains to translate these findings into clinically efficacous vaccines in man. This has been greatly facilitated by the recent identification of the equivalent Clec9A(+) XCR1(+) cross-presenting DC in human lymphoid tissues and peripheral tissues that are key sites for vaccination administration. These findings combined with further studies on DC subset biology have important implications for the design of new CTL-mediated vaccines.

  14. Alarmins Link Neutrophils and Dendritic Cells

    PubMed Central

    Yang, De; de la Rosa, Gonzalo; Tewary, Poonam; Oppenheim, Joost J.

    2009-01-01

    Neutrophils are the first major population of leukocyte to infiltrate infected or injured tissues and are crucial for initiating host innate defense and adaptive immunity. Although the contribution of neutrophils to innate immune defense is mediated predominantly by phagocytosis and killing of microorganisms, neutrophils also participate in the induction of adaptive immune responses. At sites of infection and/or injury, neutrophils release numerous mediators upon degranulation or death, among these are alarmins which have a characteristic dual capacity to mobilize and activate antigen-presenting cells. We describe here how alarmins released by neutrophil degranulation and/or death can link neutrophils to dendritic cells by promoting their recruitment and activation, resulting in the augmentation of innate and adaptive immune responses. PMID:19699678

  15. Siglecs as targets for therapy in immune cell mediated disease

    PubMed Central

    O’Reilly, Mary K.; Paulson, James C.

    2010-01-01

    The sialic acid-binding immunoglobulin-like lectins (siglecs) comprise a family of receptors that are differentially expressed on leukocytes and other immune cells. The restricted expression of several siglecs to one or a few cell types makes them attractive targets for cell-directed therapies. The anti-CD33 (Siglec-3) antibody Gemtuzumab (Mylotarg™) is approved for treatment of acute myeloid leukemia (AML), and antibodies targeting CD22 (Siglec-2) are currently in clinical trials for treatment of B cell non-Hodgkins lymphomas and autoimmune diseases. Because siglecs are endocytic receptors, they are well suited for a ‘Trojan horse’ strategy, whereby therapeutic agents conjugated to an antibody, or multimeric glycan ligand, bind to the siglec and are efficiently carried into the cell. Although the rapid internalization of unmodified siglec antibodies reduces their utility for induction of antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated cytotoxicity (CDC), antibody binding of Siglec-8, Siglec-9, and CD22 have been demonstrated to induce apoptosis of eosinophils, neutrophils, and depletion of B cells, respectively. Here we review the properties of siglecs that make them attractive for cell-targeted therapies. PMID:19359050

  16. Equiaxed Dendritic Solidification Experiment (EDSE)

    NASA Technical Reports Server (NTRS)

    Beckermann, C.; Steinbach, I.; Karma, A.; deGroh, H. C., III

    1999-01-01

    The objective of the research is to quantitatively determine and understand the fundamental mechanisms that control the microstructural evolution during solidification of an assemblage of equiaxed dendritic crystals. A microgravity experiment will be conducted to obtain benchmark data on the transient growth and interaction of up to four equiaxed crystals of a pure and transparent metal analog (succinonitrile, SCN) under strictly diffusion dominated conditions. Of interest in the experiment are the transient evolution of the primary and secondary dendrite tip speeds, the dendrite morphology (i.e., tip radii, branch spacings, etc.) and solid fraction, the tip selection criterion, and the temperature field in the melt for a range of initial supercoolings and, thus, interaction "strengths" between the crystals. The experiment thus extends the microgravity measurements of Glicksman and coworkers for steady growth of a single dendrite [Isothermal Dendritic Growth Experiment (IDGE), first flown on USMP-2] to a case where growth transients are introduced due to thermal interactions between neighboring dendrites - a situation more close to actual casting conditions. Corresponding earth-based experiments will be conducted to ascertain the influence of melt convection. The experiments are supported by a variety of analytical models and numerical simulations. The data will primarily be used to develop and test theories of transient dendritic growth and the solidification of multiple interacting equiaxed crystals in a supercooled melt.

  17. Equiaxed Dendritic Solidification Experiment (EDSE)

    NASA Technical Reports Server (NTRS)

    Beckermann, C.; Karma, A.; Steinbach, I.; deGroh, H. C., III

    2001-01-01

    The objective of the research is to quantitatively determine and understand the fundamental mechanisms that control the microstructural evolution during equiaxed dendritic solidification. A microgravity experiment will be conducted to obtain benchmark data on the transient growth and interaction of up to four equiaxed crystals of a pure and transparent metal analog (succinonitrile, SCN) under strictly diffusion-dominated conditions. Of interest in the experiment are the transient evolution of the primary and secondary dendrite tip speeds, the dendrite morphology and solid fraction, the tip selection criterion, and the temperature field in the melt for a range of interaction "strengths" between the crystals. The experiment extends the microgravity measurements of Glicksman and co-workers isothermal dendritic growth experiment (IDGE) for steady growth of a single dendrite to a case where growth transients are introduced due to thermal interactions between neighboring dendrites - a situation closer to actual casting conditions. Corresponding Earth-based experiments will be conducted to ascertain the influence of melt convection. The experiments are supported by a variety of analytical models and numerical simulations. The data will be used to develop and test theories of transient dendritic growth and the solidification of multiple interacting equiaxed crystals in a supercooled melt.

  18. Gravitational induction

    NASA Astrophysics Data System (ADS)

    Bini, Donato; Cherubini, Christian; Chicone, Carmen; Mashhoon, Bahram

    2008-11-01

    We study the linear post-Newtonian approximation to general relativity known as gravitoelectromagnetism (GEM); in particular, we examine the similarities and differences between GEM and electrodynamics. Notwithstanding some significant differences between them, we find that a special nonstationary metric in GEM can be employed to show explicitly that it is possible to introduce gravitational induction within GEM in close analogy with Faraday's law of induction and Lenz's law in electrodynamics. Some of the physical implications of gravitational induction are briefly discussed.

  19. Dendritic Growth Velocities in Microgravity

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Koss, M. B.; Winsa, E. A.

    1994-01-01

    We measured dendritic tip velocities in pure succinonitrile (SCN) in microgravity. using a sequence of telemetered binary images sent to Earth from the Space Shuttle Columbia (STS-62). Growth velocities were measured as a function of the supercooling over the range 0.05-1.5 K. Microgravity observations show that buoyancy-induced convection alters the growth kinetics of SCN dendrites at supercooling as high as 1.3 K. Also, the dendrite velocity data measured under microgravity agree well with the Ivantsov paraboloidal diffusion solution when coupled to a scaling constant of sigma(sup *) = 0.0157.

  20. Inductive reasoning.

    PubMed

    Hayes, Brett K; Heit, Evan; Swendsen, Haruka

    2010-03-01

    Inductive reasoning entails using existing knowledge or observations to make predictions about novel cases. We review recent findings in research on category-based induction as well as theoretical models of these results, including similarity-based models, connectionist networks, an account based on relevance theory, Bayesian models, and other mathematical models. A number of touchstone empirical phenomena that involve taxonomic similarity are described. We also examine phenomena involving more complex background knowledge about premises and conclusions of inductive arguments and the properties referenced. Earlier models are shown to give a good account of similarity-based phenomena but not knowledge-based phenomena. Recent models that aim to account for both similarity-based and knowledge-based phenomena are reviewed and evaluated. Among the most important new directions in induction research are a focus on induction with uncertain premise categories, the modeling of the relationship between inductive and deductive reasoning, and examination of the neural substrates of induction. A common theme in both the well-established and emerging lines of induction research is the need to develop well-articulated and empirically testable formal models of induction. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.

  1. Assessing humoral and cell-mediated immune response in Hawaiian green turtles, Chelonia mydas

    USGS Publications Warehouse

    Work, T.M.; Balazs, G.H.; Rameyer, R.A.; Chang, S.P.; Berestecky, J.

    2000-01-01

    Seven immature green turtles, Chelonia mydas, captured from Kaneohe Bay on the island of Oahu were used to evaluate methods for assessing their immune response. Two turtles each were immunized intramuscularly with egg white lysozyme (EWL) in Freunda??s complete adjuvant, Gerbu, or ISA-70; a seventh turtle was immunized with saline only and served as a control. Humoral immune response was measured with an indirect enzyme linked immunosorbent assay (ELISA). Cell-mediated immune response was measured using in vitro cell proliferation assays (CPA) using whole blood or peripheral blood mononuclear cells (PBM) cultured with concanavalin A (ConA), phytohaemagglutinin (PHA), or soluble egg EWL antigen. All turtles, except for one immunized with Gerbu and the control, produced a detectable humoral immune response by 6 weeks which persisted for at least 14 weeks after a single immunization. All turtles produced an anamnestic humoral immune response after secondary immunization. Antigen specific cell-mediated immune response in PBM was seen in all turtles either after primary or secondary immunization, but it was not as consistent as humoral immune response; antigen specific cell-mediated immune response in whole blood was rarely seen. Mononuclear cells had significantly higher stimulation indices than whole blood regardless of adjuvant, however, results with whole blood had lower variability. Both Gerbu and ISA-70 appeared to potentiate the cell-mediated immune response when PBM or whole blood were cultured with PHA. This is the first time cell proliferation assays have been compared between whole blood and PBM for reptiles. This is also the first demonstration of antigen specific cell-mediated response in reptiles. Cell proliferation assays allowed us to evaluate the cell-mediated immune response of green turtles. However, CPA may be less reliable than ELISA for detecting antigen specific immune response. Either of the three adjuvants appears suitable to safely elicit a

  2. Ca2+ signalling in postsynaptic dendrites and spines of mammalian neurons in brain slice.

    PubMed

    Müller, W; Connor, J A

    1992-01-01

    Postsynaptic Ca2+ changes are involved in control of cellular excitability and induction of synaptic long-term changes. We monitored Ca2+ changes in dendrites and spines during synaptic and direct stimulation using high resolution microfluorometry of fura-2 injected into CA3 pyramidal neurons in guinea pig hippocampal slice. When driven by current injection from an intracellular electrode or with synaptic stimulation, postsynaptic Ca2+ accumulations were highest in the proximal dendrites with a pronounced fall-off towards the soma and some fall-off towards more distal dendrites. Muscarinic activation by low concentrations of carbachol strongly increased intradendritic Ca2+ accumulation during directly-evoked repetitive firing. This enhancement occurred in large part because muscarinic activation suppressed the normal Ca(2+)-dependent activation of K-channels that mediates adaptation of firing. Repetitive firing of cholinergic fibers in the slice reproduced the effects of carbachol. Inhibition of acetylcholine-esterase activity by eserine enhanced the effects of repetitive stimulation of chlolinergic fibers. All effects were reversible and were blocked by the muscarinic antagonist atropine. Ca2+ accumulations in postsynaptic spines might be the basis of specificity of synaptic plasticity. With selective stimulation of few associative/comissural fibers, Ca2+ accumulated in single postsynaptic spines but not in the parent dendrite. With strong stimulation, dendrite levels also increased but spine levels were considerably higher. The NMDA-receptor antagonist AP-5 blocked Ca(2+)-peaks in spines, but left Ca2+ changes in dendrite shafts largely unaffected. Sustained steep Ca2+ gradients between single spines and the parent dendrite, often lasting several minutes, developed with repeated stimulation. Our results demonstrate a spine entity that can act independent from the dendrite with respect to Ca(2+)-dependent processes. Muscarinic augmentation of dendritic Ca2+ levels

  3. Analysis of cell-mediated immune responses in support of dengue vaccine development efforts.

    PubMed

    Rothman, Alan L; Currier, Jeffrey R; Friberg, Heather L; Mathew, Anuja

    2015-12-10

    Dengue vaccine development has made significant strides, but a better understanding of how vaccine-induced immune responses correlate with vaccine efficacy can greatly accelerate development, testing, and deployment as well as ameliorate potential risks and safety concerns. Advances in basic immunology knowledge and techniques have already improved our understanding of cell-mediated immunity of natural dengue virus infection and vaccination. We conclude that the evidence base is adequate to argue for inclusion of assessments of cell-mediated immunity as part of clinical trials of dengue vaccines, although further research to identify useful correlates of protective immunity is needed.

  4. Optimal Current Transfer in Dendrites

    PubMed Central

    Bird, Alex D.

    2016-01-01

    Integration of synaptic currents across an extensive dendritic tree is a prerequisite for computation in the brain. Dendritic tapering away from the soma has been suggested to both equalise contributions from synapses at different locations and maximise the current transfer to the soma. To find out how this is achieved precisely, an analytical solution for the current transfer in dendrites with arbitrary taper is required. We derive here an asymptotic approximation that accurately matches results from numerical simulations. From this we then determine the diameter profile that maximises the current transfer to the soma. We find a simple quadratic form that matches diameters obtained experimentally, indicating a fundamental architectural principle of the brain that links dendritic diameters to signal transmission. PMID:27145441

  5. LTP is accompanied by an enhanced local excitability of pyramidal neuron dendrites.

    PubMed

    Frick, Andreas; Magee, Jeffrey; Johnston, Daniel

    2004-02-01

    The propagation and integration of signals in the dendrites of pyramidal neurons is regulated, in part, by the distribution and biophysical properties of voltage-gated ion channels. It is thus possible that any modification of these channels in a specific part of the dendritic tree might locally alter these signaling processes. Using dendritic and somatic whole-cell recordings, combined with calcium imaging in rat hippocampal slices, we found that the induction of long-term potentiation (LTP) was accompanied by a local increase in dendritic excitability that was dependent on the activation of NMDA receptors. These changes favored the back-propagation of action potentials into this dendritic region with a subsequent boost in the Ca(2+) influx. Dendritic cell-attached patch recordings revealed a hyperpolarized shift in the inactivation curve of transient, A-type K(+) currents that can account for the enhanced excitability. These results suggest an important mechanism associated with LTP for shaping signal processing and controlling dendritic function.

  6. Periodic F-actin structures shape the neck of dendritic spines.

    PubMed

    Bär, Julia; Kobler, Oliver; van Bommel, Bas; Mikhaylova, Marina

    2016-11-14

    Most of the excitatory synapses on principal neurons of the forebrain are located on specialized structures called dendritic spines. Their morphology, comprising a spine head connected to the dendritic branch via a thin neck, provides biochemical and electrical compartmentalization during signal transmission. Spine shape is defined and tightly controlled by the organization of the actin cytoskeleton. Alterations in synaptic strength correlate with changes in the morphological appearance of the spine head and neck. Therefore, it is important to get a better understanding of the nanoscale organization of the actin cytoskeleton in dendritic spines. A periodic organization of the actin/spectrin lattice was recently discovered in axons and a small fraction of dendrites using super-resolution microscopy. Here we use a small probe phalloidin-Atto647N, to label F-actin in mature hippocampal primary neurons and in living hippocampal slices. STED nanoscopy reveals that in contrast to β-II spectrin antibody labelling, phalloidin-Atto647N stains periodic actin structures in all dendrites and the neck of nearly all dendritic spines, including filopodia-like spines. These findings extend the current view on F-actin organization in dendritic spines and may provide new avenues for understanding the structural changes in the spine neck during induction of synaptic plasticity, active organelle transport or tethering.

  7. Periodic F-actin structures shape the neck of dendritic spines

    PubMed Central

    Bär, Julia; Kobler, Oliver; van Bommel, Bas; Mikhaylova, Marina

    2016-01-01

    Most of the excitatory synapses on principal neurons of the forebrain are located on specialized structures called dendritic spines. Their morphology, comprising a spine head connected to the dendritic branch via a thin neck, provides biochemical and electrical compartmentalization during signal transmission. Spine shape is defined and tightly controlled by the organization of the actin cytoskeleton. Alterations in synaptic strength correlate with changes in the morphological appearance of the spine head and neck. Therefore, it is important to get a better understanding of the nanoscale organization of the actin cytoskeleton in dendritic spines. A periodic organization of the actin/spectrin lattice was recently discovered in axons and a small fraction of dendrites using super-resolution microscopy. Here we use a small probe phalloidin-Atto647N, to label F-actin in mature hippocampal primary neurons and in living hippocampal slices. STED nanoscopy reveals that in contrast to β-II spectrin antibody labelling, phalloidin-Atto647N stains periodic actin structures in all dendrites and the neck of nearly all dendritic spines, including filopodia-like spines. These findings extend the current view on F-actin organization in dendritic spines and may provide new avenues for understanding the structural changes in the spine neck during induction of synaptic plasticity, active organelle transport or tethering. PMID:27841352

  8. The Isothermal Dendritic Growth Experiment

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Koss, M. B.; Malarik, D. C.

    1998-01-01

    The growth of dendrites is one of the commonly observed forms of solidification encountered when metals and alloys freeze under low thermal gradients, as occurs in most casting and welding processes. In engineering alloys, the details of the dendritic morphology directly relates to important material responses and properties. Of more generic interest, dendritic growth is also an archetypical problem in morphogenesis, where a complex pattern evolves from simple starting conditions. Thus, the physical understanding and mathematical description of how dendritic patterns emerge during the growth process are of interest to both scientists and engineers. The Isothermal Dendritic Growth Experiment (IDGE) is a basic science experiment designed to measure, for a fundamental test of theory, the kinetics and morphology of dendritic growth without complications induced by gravity-driven convection. The IDGE, a collaboration between Rensselaer Polytechnic Institute, in Troy NY, and NASA's Lewis Research Center (LeRC) was developed over a ten year period from a ground-based research program into a space flight experiment. Important to the success of this flight experiment was provision of in situ near-real-time teleoperations during the spaceflight experiment.

  9. Temporal coherency between receptor expression, neural activity and AP-1-dependent transcription regulates Drosophila motoneuron dendrite development.

    PubMed

    Vonhoff, Fernando; Kuehn, Claudia; Blumenstock, Sonja; Sanyal, Subhabrata; Duch, Carsten

    2013-02-01

    Neural activity has profound effects on the development of dendritic structure. Mechanisms that link neural activity to nuclear gene expression include activity-regulated factors, such as CREB, Crest or Mef2, as well as activity-regulated immediate-early genes, such as fos and jun. This study investigates the role of the transcriptional regulator AP-1, a Fos-Jun heterodimer, in activity-dependent dendritic structure development. We combine genetic manipulation, imaging and quantitative dendritic architecture analysis in a Drosophila single neuron model, the individually identified motoneuron MN5. First, Dα7 nicotinic acetylcholine receptors (nAChRs) and AP-1 are required for normal MN5 dendritic growth. Second, AP-1 functions downstream of activity during MN5 dendritic growth. Third, using a newly engineered AP-1 reporter we demonstrate that AP-1 transcriptional activity is downstream of Dα7 nAChRs and Calcium/calmodulin-dependent protein kinase II (CaMKII) signaling. Fourth, AP-1 can have opposite effects on dendritic development, depending on the timing of activation. Enhancing excitability or AP-1 activity after MN5 cholinergic synapses and primary dendrites have formed causes dendritic branching, whereas premature AP-1 expression or induced activity prior to excitatory synapse formation disrupts dendritic growth. Finally, AP-1 transcriptional activity and dendritic growth are affected by MN5 firing only during development but not in the adult. Our results highlight the importance of timing in the growth and plasticity of neuronal dendrites by defining a developmental period of activity-dependent AP-1 induction that is temporally locked to cholinergic synapse formation and dendritic refinement, thus significantly refining prior models derived from chronic expression studies.

  10. Recombinant nucleocapsid-like particles from dengue-2 induce functional serotype-specific cell-mediated immunity in mice.

    PubMed

    Gil, Lázaro; Bernardo, Lídice; Pavón, Alequis; Izquierdo, Alienys; Valdés, Iris; Lazo, Laura; Marcos, Ernesto; Romero, Yaremis; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

    2012-06-01

    The interplay of different inflammatory cytokines induced during dengue virus infection plays a role in either protection or increased disease severity. In this sense, vaccine strategies incorporating whole virus are able to elicit both functional and pathological responses. Therefore, an ideal tetravalent vaccine candidate against dengue should be focused on serotype-specific sequences. In the present work, a new formulation of nucleocapsid-like particles (NLPs) obtained from the recombinant dengue-2 capsid protein was evaluated in mice to determine the level of protection against homologous and heterologous viral challenge and to measure the cytotoxicity and cytokine-secretion profiles induced upon heterologous viral stimulation. As a result, a significant protection rate was achieved after challenge with lethal dengue-2 virus, which was dependent on CD4(+) and CD8(+) cells. In turn, no protection was observed after heterologous challenge. In accordance, in vitro-stimulated spleen cells from mice immunized with NLPs from the four dengue serotypes showed a serotype-specific response of gamma interferon- and tumour necrosis factor alpha-secreting cells. A similar pattern was detected when spleen cells from dengue-immunized animals were stimulated with the capsid protein. Taking these data together, we can assert that NLPs constitute an attractive vaccine candidate against dengue. They induce a functional immune response mediated by CD4(+) and CD8(+) cells in mice, which is protective against viral challenge. In turn, they are potentially safe due to two important facts: induction of serotype specific cell-mediated immunity and lack of induction of antiviral antibodies. Further studies in non-human primates or humanized mice should be carried out to elucidate the usefulness of the NLPs as a potential vaccine candidate against dengue disease.

  11. Crucial role of IL-4/STAT6 in T cell-mediated hepatitis: up-regulating eotaxins and IL-5 and recruiting leukocytes.

    PubMed

    Jaruga, Barbara; Hong, Feng; Sun, Rui; Radaeva, Svetlana; Gao, Bin

    2003-09-15

    T cell-mediated immune responses are implicated in the pathogenesis of a variety of liver disorders; however, the underlying mechanism remains obscure. Con A injection is a widely accepted mouse model to study T cell-mediated liver injury, in which STAT6 is rapidly activated. Disruption of the IL-4 and STAT6 gene by way of genetic knockout abolishes Con A-mediated liver injury without affecting IFN-gamma/STAT1, IL-6/STAT3, or TNF-alpha/NF-kappaB signaling or affecting NKT cell activation. Infiltration of neutrophils and eosinophils in Con A-induced hepatitis is markedly suppressed in IL-4 (-/-) and STAT6(-/-) mice compared with wild-type mice. IL-4 treatment induces expression of eotaxins in hepatocytes and sinusoidal endothelial cells isolated from wild-type mice but not from STAT6(-/-) mice. Con A injection induces expression of eotaxins in the liver and elevates serum levels of IL-5 and eotaxins; such induction is markedly attenuated in IL-4(-/-) and STAT6(-/-) mice. Finally, eotaxin blockade attenuates Con A-induced liver injury and leukocyte infiltration. Taken together, these findings suggest that IL-4/STAT6 plays a critical role in Con A-induced hepatitis, via enhancing expression of eotaxins in hepatocytes and sinusoidal endothelial cells, and induces IL-5 expression, thereby facilitating recruitment of eosinophils and neutrophils into the liver and resulting in hepatitis.

  12. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages

    NASA Astrophysics Data System (ADS)

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J.; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R.; Scott, Diane; Franzoso, Guido; Cook, H. Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin αM (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS.

  13. Genetic diversity predicts pathogen resistance and cell-mediated immunocompetence in house finches

    PubMed Central

    Hawley, Dana M; Sydenstricker, Keila V; Kollias, George V; Dhondt, André A

    2005-01-01

    Evidence is accumulating that genetic variation within individual hosts can influence their susceptibility to pathogens. However, there have been few opportunities to experimentally test this relationship, particularly within outbred populations of non-domestic vertebrates. We performed a standardized pathogen challenge in house finches (Carpodacus mexicanus) to test whether multilocus heterozygosity across 12 microsatellite loci predicts resistance to a recently emerged strain of the bacterial pathogen, Mycoplasma gallisepticum (MG). We simultaneously tested whether the relationship between heterozygosity and pathogen susceptibility is mediated by differences in cell-mediated or humoral immunocompetence. We inoculated 40 house finches with MG under identical conditions and assayed both humoral and cell-mediated components of the immune response. Heterozygous house finches developed less severe disease when infected with MG, and they mounted stronger cell-mediated immune responses to phytohaemagglutinin. Differences in cell-mediated immunocompetence may, therefore, partly explain why more heterozygous house finches show greater resistance to MG. Overall, our results underscore the importance of multilocus heterozygosity for individual pathogen resistance and immunity. PMID:17148199

  14. Natural killer cell-mediated cytotoxicity is increased by a type II arabinogalactan from Anoectochilus formosanus.

    PubMed

    Yang, Li-Chan; Lai, Ching-Yi; Lin, Wen-Chuan

    2017-01-02

    This study investigated the effects of a type II arabinogalactan from Anoectochilus formosanus (AGAF) on natural killer (NK) cell-mediated cytotoxicity and the possible underlying mechanisms. This study reported that sustained exposure to AGAF increased NK-92MI cell-mediated cytotoxicity in a time- and concentration-dependent manner, as characterized according to the cellular lactic dehydrogenase leakage from K562 leukemia cells. Additionally, antibody neutralization studies have reported that interferon (IFN)-γ, but not perforin or tumor necrosis factor-α, released by NK-92MI NK cells is crucial in enhancing cytotoxicity through an autocrine loop. In this study, AGAF was further demonstrated to induce IFN-γ expression, increasing the susceptibility to NK-92MI cell-mediated cytotoxicity through the toll-like receptor (TLR)-2, TLR4, extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and nuclear factor-κB pathways. A pharmacological study revealed that Janus kinase 2/signal transducers and activators of the signal transducers and of transcription 3 signaling are involved in IFN-γ-induced NK cell-mediated cytotoxicity.

  15. Induction voidmeter

    DOEpatents

    Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Brewer, John

    1986-01-01

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  16. Induction voidmeter

    DOEpatents

    Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

    1983-12-21

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  17. Cell-Mediated Immune Function and Cytokine Regulation During Space Flight

    NASA Technical Reports Server (NTRS)

    Sams, Clarence F.; Pierson, Duane L.; Paloski, W. H. (Technical Monitor)

    2000-01-01

    The changes in immune function which occur during space flight potentially expose the crews to an increased risk for development of illness. Decreased cellular immune function has been repeatedly documented after space flight and confirmed during flight by in vivo delayed-type hypersensitivity testing. However, correlation of immune changes with a clinically significant risk factor has not yet been performed. Our hypothesis is that space flight induces a decrease in cell-mediated immune function accompanied by a shift from a type 1 cytokine pattern (favoring cell-mediated immunity) to a type 2 cytokine pattern (favoring humoral immunity). We further hypothesize that reactivation of latent viruses will occur during space flight in association with the decreased cellular immunity. To test these hypotheses, we will determine the effects of space flight on cell-mediated immunity and viral reactivation. We will utilize delayed-type hypersensitivity testing as an in vivo measure of integrated cell-mediated immune function. The production of cytokines and immunoregulatory factors by lymphocytes and monocytes will be measured to determine whether changes in cytokine patterns are associated with the space flight-induced immune dysregulation. Correlation of antigen-specific immune changes with reactivation of latent herpes viruses will be determined by measuring peripheral levels of viral (CMV, VZV, EBV) antigen-specific T cells and comparing to the levels of EBV-infected B-cells by fluorescence in situ hybridization and flow cytometry. A comparison of cell-mediated immune function, cytokine regulation and viral reactivation will provide new insights into crew member health risks during flight.

  18. Bruton's tyrosine kinase defect in dendritic cells from X-linked agammaglobulinaemia patients does not influence their differentiation, maturation and antigen-presenting cell function

    PubMed Central

    GAGLIARDI, M C; FINOCCHI, A; ORLANDI, P; CURSI, L; CANCRINI, C; MOSCHESE, V; MIYAWAKI, T; ROSSI, P

    2003-01-01

    X-linked agammaglobulinaemia (XLA) is a primary immunodeficiency disease characterized by very low levels or even absence of circulating antibodies. The immunological defect is caused by deletions or mutations of Bruton's tyrosine kinase gene (Btk), whose product is critically involved in the maturation of pre-B lymphocytes into mature B cells. Btk is expressed not only in B lymphocytes but also in cells of the myeloid lineage, including dendritic cells (DC). These cells are professional antigen presenting cells (APC) that play a fundamental role in the induction and regulation of T-cell responses. In this study, we analysed differentiation, maturation, and antigen-presenting function of DC derived from XLA patients (XLA-DC) as compared to DC from age-matched healthy subjects (healthy-DC). We found that XLA-DC normally differentiate from monocyte precursors and mature in response to lipopolysaccharide (LPS) as assessed by de novo expression of CD83, up-regulation of MHC class II, B7·1 and B7·2 molecules as well as interleukin (IL)-12 and IL-10 production. In addition, we demonstrated that LPS stimulated XLA-DC acquire the ability to prime naïve T cells and to polarize them toward a Th1 phenotype, as observed in DC from healthy donors stimulated in the same conditions. In conclusion, these data indicate that Btk defect is not involved in DC differentiation and maturation, and that XLA-DC can act as fully competent antigen presenting cells in T cell-mediated immune responses. PMID:12823285

  19. Dexamethasone and Monophosphoryl Lipid A-Modulated Dendritic Cells Promote Antigen-Specific Tolerogenic Properties on Naive and Memory CD4+ T Cells

    PubMed Central

    Maggi, Jaxaira; Schinnerling, Katina; Pesce, Bárbara; Hilkens, Catharien M.; Catalán, Diego; Aguillón, Juan C.

    2016-01-01

    Tolerogenic dendritic cells (DCs) are a promising tool to control T cell-mediated autoimmunity. Here, we evaluate the ability of dexamethasone-modulated and monophosphoryl lipid A (MPLA)-activated DCs [MPLA-tolerogenic DCs (tDCs)] to exert immunomodulatory effects on naive and memory CD4+ T cells in an antigen-specific manner. For this purpose, MPLA-tDCs were loaded with purified protein derivative (PPD) as antigen and co-cultured with autologous naive or memory CD4+ T cells. Lymphocytes were re-challenged with autologous PPD-pulsed mature DCs (mDCs), evaluating proliferation and cytokine production by flow cytometry. On primed-naive CD4+ T cells, the expression of regulatory T cell markers was evaluated and their suppressive ability was assessed in autologous co-cultures with CD4+ effector T cells and PPD-pulsed mDCs. We detected that memory CD4+ T cells primed by MPLA-tDCs presented reduced proliferation and proinflammatory cytokine expression in response to PPD and were refractory to subsequent stimulation. Naive CD4+ T cells were instructed by MPLA-tDCs to be hyporesponsive to antigen-specific restimulation and to suppress the induction of T helper cell type 1 and 17 responses. In conclusion, MPLA-tDCs are able to modulate antigen-specific responses of both naive and memory CD4+ T cells and might be a promising strategy to “turn off” self-reactive CD4+ effector T cells in autoimmunity. PMID:27698654

  20. Homophilic Dscam interactions control complex dendrite morphogenesis

    PubMed Central

    Hughes, Michael E.; Bortnick, Rachel; Tsubouchi, Asako; Bäumer, Philipp; Kondo, Masahiro; Uemura, Tadashi; Schmucker, Dietmar

    2007-01-01

    Summary The morphogenesis of complex dendritic fields requires highly specific patterning and dendrite-dendrite recognition mechanisms. Alternative splicing of the Drosophila cell surface receptor Dscam results in up to 38,016 different receptor isoforms and in vitro binding studies suggested that sequence variability in immunoglobulin-like ecto-domains determines the specificity of strictly homophilic interactions. We report that diverse Dscam receptors play an important role in controlling cell-intrinsic aspects of dendrite guidance. We examined the function of Dscam during morphogenesis of dendrite arborization neurons (“da” neurons) and found that loss of Dscam in single neurons causes abnormal dendritic fasciculation and a strong increase in self-crossing of dendritic branches of da neurons. Restriction of dendritic fields of neighboring class III neurons appeared intact in Dscam deficient neurons suggesting that dendritic self-avoidance but not hetero-neuronal tiling may depend on Dscam function. Over-expression of the same Dscam isoforms in two da neurons with normally overlapping dendritic fields forced a spatial segregation of the two dendritic fields. Taken together, our results suggest that dendritic branches of all four classes of da neurons use isoform-specific homophilic interactions of Dscam to ensure minimal overlap of dendrites. The large pool of Dscam’s extracellular recognition domains may allow the same ‘core’ repulsion mechanism to be used in every da neuron without interfering with hetero-neuronal interactions. PMID:17481395

  1. Dengue virus-infected human dendritic cells reveal hierarchies of naturally expressed novel NS3 CD8 T cell epitopes.

    PubMed

    Piazza, P; Campbell, D; Marques, E; Hildebrand, W H; Buchli, R; Mailliard, R; Rinaldo, C R

    2014-09-01

    Detailed knowledge of dengue virus (DENV) cell-mediated immunity is limited. In this study we characterize CD8(+) T lymphocytes recognizing three novel and two known non-structural protein 3 peptide epitopes in DENV-infected dendritic cells. Three epitopes displayed high conservation (75-100%), compared to the others (0-50%). A hierarchy ranking based on magnitude and polyfunctionality of the antigen-specific response showed that dominant epitopes were both highly conserved and cross-reactive against multiple DENV serotypes. These results are relevant to DENV pathogenesis and vaccine design.

  2. HIV is trapped and masked in the cytoplasm of lymph node follicular dendritic cells.

    PubMed Central

    Tacchetti, C.; Favre, A.; Moresco, L.; Meszaros, P.; Luzzi, P.; Truini, M.; Rizzo, F.; Grossi, C. E.; Ciccone, E.

    1997-01-01

    To gain further insight into the pathogenesis of human immunodeficiency virus (HIV) infection, lymph nodes from seven asymptomatic HIV+ subjects were analyzed during the latent phase of disease. Both ultrastructural and immunohistochemical analyses revealed that, in all of the cases, plasma cells producing IgM/gamma were present in germinal centers. Secreted immunoglobulins formed extracellular deposits mimicking the follicular dendritic cell network. Immunoglobulin produced by germinal center plasma cells are specific for HIV because they bind the HIV env protein gp 120. Plasma cells producing antibodies with the same specificity were also abundant in the extrafollicular regions of lymph nodes. During the latent phase of infection, the virus largely accumulates within the germinal centers. Therefore, extracellular immunoglobulin may form immune complexes, as shown by the presence of HIV-specific antibodies, HIV particles, and complement components C3c, C3d, and C1q in the interdendritic spaces. When the ultrastructural localization of HIV in germinal centers was analyzed, abundant virus particles were found in the interdendritic spaces. In addition to this extracellular localization of HIV, receptor-mediated endocytosis of viral particles by follicular dendritic cells was observed. Complete HIV particles were found within the endosomal compartment of the follicular dendritic cells and, as complete viral particles, free in the cytoplasm, indicating that the virus may escape from the endocytic compartment. As the virus is abundant in the cytoplasm, this event leads to formation of a hidden reservoir within follicular dendritic cells. In this location, HIV escapes recognition by cytotoxic T lymphocytes. In contrast, virus budding indicating a productive infection of follicular dendritic cells that would render them susceptible to T-cell-mediated lysis has been seldom observed. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9033269

  3. A lectin from Chinese mistletoe increases gammadelta T cell-mediated cytotoxicity through induction of caspase-dependent apoptosis.

    PubMed

    Gong, Fang; Ma, Yanhui; Ma, Anlun; Yu, Qiwen; Zhang, Jiying; Nie, Hong; Chen, Xuehua; Shen, Baihua; Li, Ningli; Zhang, Dongqing

    2007-06-01

    In this study, a mistletoe lectin (ML) was purified from Chinese mistletoe and the effect of this 60 kDa Chinese ML on human gammadelta T cell cytotoxicity, apoptosis and modulation of the cytokine network was studied. The cytotoxic properties of delta T cells was evaluated by using a (51)Cr release test and employed fluorescence-activated cell sorting and enzyme-linked immunosorbent assay analysis to quantify translocation of the cell membrane phospholipid, phosphatidylserine and nuclear DNA fragmentation during apoptosis. It was found that: (i) ML effectively stimulated gammadelta T cell proliferation in a dose- and time-dependent manner; (ii) ML increased gammadelta T cell cytotoxicity; (iii) ML could modulate lipopolysaccharide-induced cytokine release in a pro-inflammatory manner by increasing tumor necrosis factor (TNF)-alpha release and inhibiting the release of anti-inflammatory interleukin (IL)-10; (iv) ML induced apoptosis in caspase-dependent and CD95-independent manner. The results indicated that ML is a potent immunomodulator to human gammadelta T cell cytotoxicity, apoptos is and cytokine production.

  4. Induction of foetal haemoglobin synthesis in erythroid progenitor stem cells: mediated by water-soluble components of Terminalia catappa.

    PubMed

    Aimola, I A; Inuwa, H M; Nok, A J; Mamman, A I

    2014-06-01

    Current novel therapeutic agents for the treatment of sickle cell anaemia (SCA) focus on increasing foetal haemoglobin (HbF) levels in SCA patients. Unfortunately, the only approved HbF-inducing agent, hydroxyurea, has long-term unpredictable side effects. Studies have shown the potential of plant compounds to modulate HbF synthesis in primary erythroid progenitor stem cells. We isolated a novel HbF-inducing Terminalia catappa distilled water active fraction (TCDWF) from Terminalia catappa leaves that induced the commitment of erythroid progenitor stem cells to the erythroid lineage and relatively higher HbF synthesis of 9.2- and 6.8-fold increases in both erythropoietin (EPO)-independent and EPO-dependent progenitor stem cells respectively. TCDWF was differentially cytotoxic to EPO-dependent and EPO-independent erythroid progenitor stem cell cultures as revealed by lactate dehydrogenase release from the cells. TCDWF demonstrated a protective effect on EPO-dependent and not EPO-independent progenitor cells. TCDWF induced a modest increase in caspase 3 activity in EPO-independent erythroid progenitor stem cell cultures compared with a significantly higher (P˂0.05) caspase 3 activity in EPO-dependent ones. The results demonstrate that TCDWF may hold promising HbF-inducing compounds, which work synergistically, and suggest a dual modulatory effect on erythropoiesis inherent in this active fraction.

  5. Gravitational effects in dendritic growth

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Singh, N. B.; Chopra, M.

    1983-01-01

    The theories of diffusion-controlled dendritic crystallization will be reviewed briefly, along with recently published critical experiments on the kinetics and morphology of dendritic growth in pure substances. The influence of the gravitational body force on dendrite growth kinetics will be shown to be highly dependent on the growth orientation with respect to the gravity vector and on the level of the thermal supercooling. In fact, an abrupt transition occurs at a critical supercooling, above which diffusional transport dominates the growth process and below which convective transport dominates. Our most recent work on binary mixtures shows that dilute solute additions influence the crystallization process indirectly, by altering the interfacial stability, rather than by directly affecting the transport mode. Directions for future studies in this field will also be discussed.

  6. Directing dendritic cell immunotherapy towards successful cancer treatment

    PubMed Central

    Sabado, Rachel Lubong; Bhardwaj, Nina

    2010-01-01

    The use of dendritic cells (DCs) for tumor immunotherapy represents a powerful approach for harnessing the patient's own immune system to eliminate tumor cells. However, suboptimal conditions for generating potent immunostimulatory DCs, as well as the induction of tolerance and suppression mediated by the tumors and its microenvironment have contributed to limited success. Combining DC vaccines with new approaches that enhance immunogenicity and overcome the regulatory mechanisms underlying peripheral tolerance may be the key to achieving effective and durable anti-tumor immune responses that translate to better clinical outcomes. PMID:20473346

  7. An inverse approach for elucidating dendritic function.

    PubMed

    Torben-Nielsen, Benjamin; Stiefel, Klaus M

    2010-01-01

    We outline an inverse approach for investigating dendritic function-structure relationships by optimizing dendritic trees for a priori chosen computational functions. The inverse approach can be applied in two different ways. First, we can use it as a "hypothesis generator" in which we optimize dendrites for a function of general interest. The optimization yields an artificial dendrite that is subsequently compared to real neurons. This comparison potentially allows us to propose hypotheses about the function of real neurons. In this way, we investigated dendrites that optimally perform input-order detection. Second, we can use it as a "function confirmation" by optimizing dendrites for functions hypothesized to be performed by classes of neurons. If the optimized, artificial, dendrites resemble the dendrites of real neurons the artificial dendrites corroborate the hypothesized function of the real neuron. Moreover, properties of the artificial dendrites can lead to predictions about yet unmeasured properties. In this way, we investigated wide-field motion integration performed by the VS cells of the fly visual system. In outlining the inverse approach and two applications, we also elaborate on the nature of dendritic function. We furthermore discuss the role of optimality in assigning functions to dendrites and point out interesting future directions.

  8. Novel Cell-Penetrating Peptide-Based Vaccine Induces Robust CD4+ and CD8+ T Cell-Mediated Antitumor Immunity.

    PubMed

    Derouazi, Madiha; Di Berardino-Besson, Wilma; Belnoue, Elodie; Hoepner, Sabine; Walther, Romy; Benkhoucha, Mahdia; Teta, Patrick; Dufour, Yannick; Yacoub Maroun, Céline; Salazar, Andres M; Martinvalet, Denis; Dietrich, Pierre-Yves; Walker, Paul R

    2015-08-01

    Vaccines that can coordinately induce multi-epitope T cell-mediated immunity, T helper functions, and immunologic memory may offer effective tools for cancer immunotherapy. Here, we report the development of a new class of recombinant protein cancer vaccines that deliver different CD8(+) and CD4(+) T-cell epitopes presented by MHC class I and class II alleles, respectively. In these vaccines, the recombinant protein is fused with Z12, a novel cell-penetrating peptide that promotes efficient protein loading into the antigen-processing machinery of dendritic cells. Z12 elicited an integrated and multi-epitopic immune response with persistent effector T cells. Therapy with Z12-formulated vaccines prolonged survival in three robust tumor models, with the longest survival in an orthotopic model of aggressive brain cancer. Analysis of the tumor sites showed antigen-specific T-cell accumulation with favorable modulation of the balance of the immune infiltrate. Taken together, the results offered a preclinical proof of concept for the use of Z12-formulated vaccines as a versatile platform for the development of effective cancer vaccines.

  9. Impaired cell mediated immunity in haemophilia in the absence of infection with human immunodeficiency virus.

    PubMed Central

    Madhok, R; Gracie, A; Lowe, G D; Burnett, A; Froebel, K; Follett, E; Forbes, C D

    1986-01-01

    The cell mediated immune response was evaluated in vivo in 29 patients with clinically severe haemophilia by means of the dinitrochlorobenzene skin test. All patients had a response below the median normal value, and in 19 the response was on or below the lower limit of the normal range. There was no difference in skin response between patients positive and negative for the human immunodeficiency virus (HIV; formerly known as human T cell lymphotropic virus III or lymphadenopathy associated virus). In the whole group, and in seronegative patients (n = 17), there was an inverse relation between exposure to clotting factor and skin response. In seropositive patients (n = 12) no such association was apparent. This study shows that clotting factor concentrate impairs the cell mediated immune response to a new antigen in the absence of infection with HIV. PMID:3094762

  10. Cell-mediated and humoral immune response in diabetic patients with periodontitis.

    PubMed

    Anil, S; Remani, P; Vijayakumar, T; Hari, S

    1990-07-01

    Cell-mediated and humoral immune responses were assessed in 50 patients with type II or non-insulin-dependent diabetes mellitus and 50 nondiabetic patients with periodontitis. The values were compared with those of 50 age and sex-matched control subjects. The cell-mediated immunity assessed by enumerating the total and high-affinity rosette-forming cells of the patient did not show any significant variation from that of the normal control subjects. The humoral immune response was assessed by estimating serum immunoglobulins G, A, M, D, and E by single radial immunodiffusion. Except IgD, all other immunoglobulins were found to be elevated significantly in both diabetic and nondiabetic subjects. The alteration in humoral immune response may be the cause or the effect of periodontitis. The defective host response reported in diabetic patients may be responsible for the increased incidence of periodontitis in diabetic patients as compared to nondiabetic patients.

  11. Cell-mediated and humoral immune responses in patients with localized juvenile periodontitis.

    PubMed

    Anil, S; Hari, S; Remani, P; Vijayakumar, T; Ankathil, R

    1990-03-01

    Cell-mediated and humoral immune responses were assessed in 21 patients with localized juvenile periodontitis (LJP), and in an equal number of control subjects. The cell-mediated immunity, assessed by enumeration of total rosette forming cells [TRFC] and high affinity rosette forming cells [HARFC], was found to be depressed in LJP patients compared to controls. Estimation of serum immunoglobulins G,A,M,D and E levels were done using single radial immunodiffusion. All the immunoglobulins except IgD were found to be elevated significantly in LJP patients. The defective immune response found in LJP patients may be the cause or effect of the disease process. Further investigations are necessary to determine whether these defects are genetically controlled.

  12. Noninvasive Imaging of Cell-Mediated Therapy for Treatment of Cancer

    PubMed Central

    Akins, Elizabeth J.; Dubey, Purnima

    2013-01-01

    Cell-mediated therapy (immunotherapy) for the treatment of cancer is an active area of investigation in animal models and clinical trials. Despite many advances, objective responses to immunotherapy are observed in a small number of cases, for certain tumor types. To better understand differences in outcomes, it is critical to develop assays for tracking effector cell localization and function in situ. The fairly recent use of molecular imaging techniques to track cell populations has presented researchers and clinicians with a powerful diagnostic tool for determining the efficacy of cell-mediated therapy for the treatment of cancer. This review highlights the application of whole-body noninvasive radioisotopic, magnetic, and optical imaging methods for monitoring effector cells in vivo. Issues that affect sensitivity of detection, such as methods of cell marking, efficiency of cell labeling, toxicity, and limits of detection of imaging modalities, are discussed. PMID:18523073

  13. Fas involvement in Ca(2+)-independent T cell-mediated cytotoxicity.

    PubMed

    Rouvier, E; Luciani, M F; Golstein, P

    1993-01-01

    Mechanisms of T cell-mediated cytotoxicity remain poorly defined at the molecular level. To investigate some of these mechanisms, we used as target cells, on the one hand, thymocytes from lpr and gld mouse mutants, and on the other hand, L1210 cells transfected or not with the apoptosis-inducing Fas molecule. These independent mutant or transfectant-based approaches both led to the conclusion that Fas was involved in the Ca(2+)-independent component of cytotoxicity mediated by at least two sources of T cells, namely nonantigen-specific in vitro activated hybridoma cells, and antigen-specific in vivo raised peritoneal exudate lymphocytes. Thus, in these cases, T cell-mediated cytotoxicity involved transduction via Fas of the target cell death signal.

  14. Saos-2 cell-mediated mineralization on collagen gels: Effect of densification and bioglass incorporation.

    PubMed

    Liu, Gengbo; Pastakia, Meet; Fenn, Michael B; Kishore, Vipuil

    2016-05-01

    Plastic compression is a collagen densification process that has been widely used for the development of mechanically robust collagen-based materials. Incorporation of bioglass within plastically compressed collagen gels has been shown to mimic the microstructural properties of native bone and enhance in vitro cell-mediated mineralization. The current study seeks to decouple the effects of collagen densification and bioglass incorporation to understand the interplay between collagen packing density and presence of bioglass on cell-mediated mineralization. Saos-2 cell-mediated mineralization was assessed as a measure of the osteoconductivity of four different collagen gels: (1) uncompressed collagen gel (UC), (2) bioglass incorporated uncompressed collagen gel (UC + BG), (3) plastically compressed collagen gel (PC), and (4) bioglass incorporated plastically compressed collagen gel (PC + BG). The results indicated that collagen densification enhanced mineralization as shown by SEM, increased alkaline phosphatase activity and produced significantly higher amounts of mineralized nodules on PC gels compared to UC gels. Further, the amount of nodule formation on PC gels was significantly higher compared to UC + BG gels indicating that increase in matrix stiffness due to collagen densification had a greater effect on cell-mediated mineralization compared to bioglass incorporation into loosely packed UC gels. Incorporation of bioglass into PC gels further enhanced mineralization as evidenced by significantly larger nodule size and higher amount of mineralization on PC + BG gels compared to PC gels. In conclusion, collagen densification via plastic compression improves the osteoconductivity of collagen gels. Further, incorporation of bioglass within PC gels has an additive effect and further enhances the osteoconductivity of collagen gels.

  15. RB mutation and RAS overexpression induce resistance to NK cell-mediated cytotoxicity in glioma cells.

    PubMed

    Orozco-Morales, Mario; Sánchez-García, Francisco Javier; Golán-Cancela, Irene; Hernández-Pedro, Norma; Costoya, Jose A; de la Cruz, Verónica Pérez; Moreno-Jiménez, Sergio; Sotelo, Julio; Pineda, Benjamín

    2015-01-01

    Several theories aim to explain the malignant transformation of cells, including the mutation of tumor suppressors and proto-oncogenes. Deletion of Rb (a tumor suppressor), overexpression of mutated Ras (a proto-oncogene), or both, are sufficient for in vitro gliomagenesis, and these genetic traits are associated with their proliferative capacity. An emerging hallmark of cancer is the ability of tumor cells to evade the immune system. Whether specific mutations are related with this, remains to be analyzed. To address this issue, three transformed glioma cell lines were obtained (Rb(-/-), Ras(V12), and Rb(-/-)/Ras(V12)) by in vitro retroviral transformation of astrocytes, as previously reported. In addition, Ras(V12) and Rb(-/-)/Ras(V12) transformed cells were injected into SCID mice and after tumor growth two stable glioma cell lines were derived. All these cells were characterized in terms of Rb and Ras gene expression, morphology, proliferative capacity, expression of MHC I, Rae1δ, and Rae1αβγδε, mult1, H60a, H60b, H60c, as ligands for NK cell receptors, and their susceptibility to NK cell-mediated cytotoxicity. Our results show that transformation of astrocytes (Rb loss, Ras overexpression, or both) induced phenotypical and functional changes associated with resistance to NK cell-mediated cytotoxicity. Moreover, the transfer of cell lines of transformed astrocytes into SCID mice increased resistance to NK cell-mediated cytotoxicity, thus suggesting that specific changes in a tumor suppressor (Rb) and a proto-oncogene (Ras) are enough to confer resistance to NK cell-mediated cytotoxicity in glioma cells and therefore provide some insight into the ability of tumor cells to evade immune responses.

  16. Loss of PTEN promotes resistance to T cell-mediated immunotherapy

    PubMed Central

    Peng, Weiyi; Chen, Jie Qing; Liu, Chengwen; Malu, Shruti; Creasy, Caitlin; Tetzlaff, Michael T; Xu, Chunyu; McKenzie, Jodi A; Zhang, Chunlei; Liang, Xiaoxuan; Williams, Leila J; Deng, Wanleng; Chen, Guo; Mbofung, Rina; Lazar, Alexander J; Torres-Cabala, Carlos A; Cooper, Zachary A; Chen, Pei-Ling; Tieu, Trang N; Spranger, Stefani; Yu, Xiaoxing; Bernatchez, Chantale; Forget, Marie-Andree; Haymaker, Cara; Amaria, Rodabe; McQuade, Jennifer L; Glitza, Isabella C; Cascone, Tina; Li, Haiyan S; Kwong, Lawrence N; Heffernan, Timothy P; Hu, Jianhua; Bassett, Roland L; Bosenberg, Marcus W; Woodman, Scott E; Overwijk, Willem W; Lizée, Gregory; Roszik, Jason; Gajewski, Thomas F; Wargo, Jennifer A; Gershenwald, Jeffrey E; Radvanyi, Laszlo; Davies, Michael A; Hwu, Patrick

    2015-01-01

    T cell-mediated immunotherapies are promising cancer treatments. However, most patients still fail to respond to these therapies. The molecular determinants of immune resistance are poorly understood. We show that loss of PTEN in tumor cells in preclinical models of melanoma inhibits T cell-mediated tumor killing and decreases T cell trafficking into tumors. In patients, PTEN loss correlates with decreased T cell infiltration at tumor sites, reduced likelihood of successful T cell expansion from resected tumors, and inferior outcomes with PD-1 inhibitor therapy. PTEN loss in tumor cells increased the expression of immunosuppressive cytokines, resulting in decreased T cell infiltration in tumors, and inhibited autophagy, which decreased T cell-mediated cell death. Treatment with a selective PI3Kβ inhibitor improved the efficacy of both anti-PD-1 and anti-CTLA4 antibodies in murine models. Together these findings demonstrate that PTEN loss promotes immune resistance and support the rationale to explore combinations of immunotherapies and PI3K-AKT pathway inhibitors. PMID:26645196

  17. Differential effect of pancreatectomy on humoral and cell-mediated immune responses.

    PubMed Central

    Fabris, N; Piantanelli, L

    1977-01-01

    Cell-mediated immune reactions, such as allogenic skin-graft rejection and PHA or MLC responses, and antibody synthesis against different antigens (sheep erythrocytes, Brucella antigen, bovine serum albumin) have been evaluated in rats suffering from experimentally-induced diabetes and in age-matched sham-treated controls. Cell-mediated immune reactions are strongly depressed diabetic rats. The cellularity of the thymus and of thymus-dependent areas and the number of peripheral blood lymphocytes is significantly reduced in pancreatectomized rats. Moreover, the immunological recovery from heavy cortisonization is also greatly impaired. Daily treatment with insulin may prevent these immunological alterations. By contrast, antibody responses in diabetic rats are not quantitatively altered in respect to either the number of antibody producing cells in the spleen or the circulating antibody titres. The discrepancy between the abnormality of cell-mediated immune reactions in diabetic rats and their physiological capacity to synthetize antibodies suggests that the sensitivity to an insulin-deprived environment is present only in a definite, although yet undefined, subpopulation of lymphoid cells rather than in the whole lymphoid system. Images Fig. 4 PMID:141353

  18. Bone marrow-derived dendritic cells.

    PubMed

    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.

  19. Regulation of dendrite morphogenesis by extrinsic cues.

    PubMed

    Valnegri, Pamela; Puram, Sidharth V; Bonni, Azad

    2015-07-01

    Dendrites play a central role in the integration and flow of information in the nervous system. The morphogenesis and maturation of dendrites is hence an essential step in the establishment of neuronal connectivity. Recent studies have uncovered crucial functions for extrinsic cues in the development of dendrites. We review the contribution of secreted polypeptide growth factors, contact-mediated proteins, and neuronal activity in distinct phases of dendrite development. We also highlight how extrinsic cues influence local and global intracellular mechanisms of dendrite morphogenesis. Finally, we discuss how these studies have advanced our understanding of neuronal connectivity and have shed light on the pathogenesis of neurodevelopmental disorders.

  20. Induction of antigen-positive cell death by the expression of perforin, but not DTa, from a DNA vaccine enhances the immune response.

    PubMed

    Gargett, Tessa; Grubor-Bauk, Branka; Garrod, Tamsin J; Yu, Wenbo; Miller, Darren; Major, Lee; Wesselingh, Steve; Suhrbier, Andreas; Gowans, Eric J

    2014-04-01

    The failure of traditional protein-based vaccines to prevent infection by viruses such as HIV or hepatitis C highlights the need for novel vaccine strategies. DNA vaccines have shown promise in small animal models, and are effective at generating anti-viral T cell-mediated immune responses; however, they have proved to be poorly immunogenic in clinical trials. We propose that the induction of necrosis will enhance the immune response to vaccine antigens encoded by DNA vaccines, as necrotic cells are known to release a range of intracellular factors that lead to dendritic cell (DC) activation and enhanced cross-presentation of antigen. Here we provide evidence that induction of cell death in DNA vaccine-targeted cells provides an adjuvant effect following intradermal vaccination of mice; however, this enhancement of the immune response is dependent on both the mechanism and timing of cell death after antigen expression. We report that a DNA vaccine encoding the cytolytic protein, perforin, resulted in DC activation, enhanced broad and multifunctional CD8 T-cell responses to the HIV-1 antigen GAG and reduced viral load following challenge with a chimeric virus, EcoHIV, compared with the canonical GAG DNA vaccine. This effect was not observed for a DNA vaccine encoding an apoptosis-inducing toxin, DTa, or when the level of perforin expression was increased to induce cell death sooner after vaccination. Thus, inducing lytic cell death following a threshold level of expression of a viral antigen can improve the immunogenicity of DNA vaccines, whereas apoptotic cell death has an inhibitory effect on the immune response.

  1. Advanced dendritic web growth development

    NASA Technical Reports Server (NTRS)

    Hopkins, R. H.

    1985-01-01

    A program to develop the technology of the silicon dendritic web ribbon growth process is examined. The effort is being concentrated on the area rate and quality requirements necessary to meet the JPL/DOE goals for terrestrial PV applications. Closed loop web growth system development and stress reduction for high area rate growth is considered.

  2. Chronic stress-induced hippocampal dendritic retraction requires CA3 NMDA receptors

    PubMed Central

    Christian, Kimberly M.; Miracle, Angela D.; Wellman, Cara L.; Nakazawa, Kazu

    2010-01-01

    Chronic stress induces dendritic retraction in the hippocampal CA3 subregion, but the mechanisms responsible for this retraction and its impact on neural circuitry are not well understood. To determine the role of NMDA (N-methyl-D-aspartic acid) receptor (NMDAR)-mediated signaling in this process, we compared the effects of chronic immobilization stress (CIS) on hippocampal dendritic morphology, hypothalamic-pituitary-adrenal (HPA) axis activation, and anxiety-related and hippocampus-dependent behaviors, in transgenic male mice in which the NMDAR had been selectively deleted in CA3 pyramidal cells and in non-mutant littermates. We found that CIS exposure for 10 consecutive days in non-mutant mice effectively induces HPA axis activation and dendritic retraction of CA3 short-shaft pyramidal neurons, but not CA3 long-shaft pyramidal neurons, suggesting a differential cellular stress response in this region. Dendritic reorganization of short-shaft neurons occurred throughout the longitudinal axis of the hippocampus and, in particular, in the ventral pole of this structure. We also observed a robust retraction of dendrites in dorsal CA1 pyramidal neurons in the non-mutant C57BL/6 mouse strain. Strikingly, chronic stress-induced dendritic retraction was not evident in any of the neurons in either CA3 or CA1 in the mutant mice that had a functional lack of NMDARs restricted to CA3 pyramidal neurons. Interestingly, the prevention of dendritic retraction in the mutant mice had a minimal effect on HPA axis activation and behavioral alterations that were induced by chronic stress. These data support a role for NMDAR-dependent glutamatergic signaling in CA3 in the cell-type specific induction of dendritic retraction in two hippocampal subregions following chronic stress. PMID:21108993

  3. The novel focal adhesion gene kindlin-2 promotes the invasion of gastric cancer cells mediated by tumor-associated macrophages.

    PubMed

    Shen, Zhanlong; Ye, Yingjiang; Kauttu, Tuuli; Seppänen, Hanna; Vainionpää, Sanna; Wang, Shan; Mustonen, Harri; Puolakkainen, Pauli

    2013-02-01

    Kindlin-2 is a novel focal adhesion gene mediating the cell-extracellular matrix (ECM) adhesion. Tumor-associated macrophages (TAMs) play an important role in linking chronic inflammation to cancer progression. Both kindlin-2 and TAMs have been found to promote the invasion of gastric cancer cells in our previous studies. However, the correlation between kindlin-2 and TAMs remains unclear. Real-time RT-PCR was used to investigate kindlin-2 expression in the AGS, NCI and Hs-746T gastric cancer cell lines co-cultured with TAMs under normal or hypoxic conditions. IL8, IL10, IL11, IL17b, IL18, IL22 and IL24 expressions were measured by real-time RT-PCR in the gastric cancer lines with varying levels of kindlin-2 expression, as well as after downregulation of kindlin-2 mRNA expression by the siRNA method. We found that kindlin-2 was upregulated in all three gastric cancer cell lines when co-cultured with TAMs under normal conditions. Under hypoxic conditions, the induction of kindlin-2 expression induced by macrophages was significantly downregulated in the Hs-746T cell line. IL8, IL11, IL17b, IL22 and IL24 expression was significantly higher in gastric cell lines with high kindlin-2 expression. Downregulation of kindlin-2 mRNA decreased IL10, IL11, IL17b, IL22 and IL24 expression but IL8 and IL18 expression was upregulated. Therefore, the novel focal adhesion gene kindlin-2 may play an important role in promoting the invasion of gastric cancer cells mediated by TAMs through regulating interleukin expression.

  4. Molecular and cellular mechanisms of dendritic morphogenesis

    PubMed Central

    Gao, Fen-Biao

    2008-01-01

    Summary Dendrites exhibit unique cell-type specific branching patterns and targeting specificity that are critically important for neuronal function and connectivity. Recent evidence indicates that highly complex transcriptional regulatory networks dictate various aspects of dendritic outgrowth, branching, and routing. In addition to other intrinsic molecular pathways such as membrane protein trafficking, interactions between neighboring dendritic branches also contribute to the final specification of dendritic morphology. Nonredundant coverage by dendrites of same type of neurons, known as tiling, requires the actions of the Tricornered/Furry (Sax-1/Sax-2) signaling pathway. However, the dendrites of a neuron do not cross over each other, a process called self-avoidance that is mediated by Down’s syndrome cell adhesion molecule (Dscam). Those exciting findings have enhanced significantly our understanding of dendritic morphogenesis and revealed the magnitude of complexity in the underlying molecular regulatory networks. PMID:17933513

  5. Evidence that dendritic mitochondria negatively regulate dendritic branching in pyramidal neurons in the neocortex.

    PubMed

    Kimura, Toshiya; Murakami, Fujio

    2014-05-14

    The precise branching patterns of dendritic arbors have a profound impact on information processing in individual neurons and the brain. These patterns are established by positive and negative regulation of the dendritic branching. Although the mechanisms for positive regulation have been extensively investigated, little is known about those for negative regulation. Here, we present evidence that mitochondria located in developing dendrites are involved in the negative regulation of dendritic branching. We visualized mitochondria in pyramidal neurons of the mouse neocortex during dendritic morphogenesis using in utero electroporation of a mitochondria-targeted fluorescent construct. We altered the mitochondrial distribution in vivo by overexpressing Mfn1, a mitochondrial shaping protein, or the Miro-binding domain of TRAK2 (TRAK2-MBD), a truncated form of a motor-adaptor protein. We found that dendritic mitochondria were preferentially targeted to the proximal portion of dendrites only during dendritic morphogenesis. Overexpression of Mfn1 or TRAK2-MBD depleted mitochondria from the dendrites, an effect that was accompanied by increased branching of the proximal portion of the dendrites. This dendritic abnormality cannot be accounted for by changes in the distribution of membrane trafficking organelles since the overexpression of Mfn1 did not alter the distributions of the endoplasmic reticulum, Golgi, or endosomes. Additionally, neither did these constructs impair neuronal viability or mitochondrial function. Therefore, our results suggest that dendritic mitochondria play a critical role in the establishment of the precise branching pattern of dendritic arbors by negatively affecting dendritic branching.

  6. Perinatal undernutrition attenuates field excitatory postsynaptic potentials and influences dendritic spine density and morphology in hippocampus of male rat offspring.

    PubMed

    Zhang, Y; Wei, J; Yang, Z

    2013-08-06

    Perinatal undernutrition affects the hippocampus, a brain region crucial for learning and memory. However, far less is known about the changes of dendritic spine density and morphology related to hippocampal synaptic plasticity. As dendritic spines are dynamic structures essential for synaptic plasticity and serve as the primary post-synaptic location of the excitatory neurotransmission that underlies learning and memory, the aim of the present study was to investigate whether the perinatal undernutrition affected hippocampal synaptic plasticity accompanied by the change of dendritic spines in anesthetized rats. An input-output curve was first determined using the measurements of field excitatory postsynaptic potential (fEPSP) slope in response to a series of stimulation intensities. Long-term potentiation (LTP) induced by high-frequency stimulation was recorded in the Schaffer collateral-CA1 pathway. Post-tetanic potentiation derived from the fEPSP slope was also measured immediately after LTP induction. Quantitative data of dendritic spines from hippocampal CA1 pyramidal cells were obtained using Golgi staining. The results showed that 50% perinatal food restriction (FR50) impaired the magnitude of LTP of the fEPSP slope in the Schaffer collateral-CA1 pathway. Additionally, FR50 reduced overall spine densities in both basal dendrites and apical dendrites of hippocampal CA1 pyramidal cells. Moreover, FR50 reduced type densities of thin and mushroom spines in apical dendrites, whereas a reduction in the type of mushroom spines was only observed in the basal dendrites of hippocampal CA1 pyramidal cells. These findings suggested that perinatal undernutrition decreased excitatory synaptic input and further affected the processing of information in a given network by selectively reducing the number of special dendritic spines. Thus, these changes in the density and the types of dendritic spines in CA1 pyramidal neurons may partly explain the impaired hippocampal

  7. Phenotype and function of nasal dendritic cells

    PubMed Central

    Lee, Haekyung; Ruane, Darren; Law, Kenneth; Ho, Yan; Garg, Aakash; Rahman, Adeeb; Esterházy, Daria; Cheong, Cheolho; Goljo, Erden; Sikora, Andrew G.; Mucida, Daniel; Chen, Benjamin; Govindraj, Satish; Breton, Gaëlle; Mehandru, Saurabh

    2015-01-01

    Intranasal vaccination generates immunity across local, regional and distant sites. However, nasal dendritic cells (DC), pivotal for the induction of intranasal vaccine- induced immune responses, have not been studied in detail. Here, using a variety of parameters, we define nasal DCs in mice and humans. Distinct subsets of “classical” DCs, dependent on the transcription factor zbtb46 were identified in the murine nose. The murine nasal DCs were FLT3 ligand-responsive and displayed unique phenotypic and functional characteristics including the ability to present antigen, induce an allogeneic T cell response and migrate in response to LPS or live bacterial pathogens. Importantly, in a cohort of human volunteers, BDCA-1+ DCs were observed to be the dominant nasal DC population at steady state. During chronic inflammation, the frequency of both BDCA-1+ and BDCA-3hi DCs was reduced in the nasal tissue, associating the loss of these immune sentinels with chronic nasal inflammation. The present study is the first detailed description of the phenotypic, ontogenetic and functional properties of nasal DCs and will inform the design of preventative immunization strategies as well as therapeutic modalities against chronic rhinosinusitis. PMID:25669151

  8. Follicular dendritic cells in health and disease

    PubMed Central

    El Shikh, Mohey Eldin M.; Pitzalis, Costantino

    2012-01-01

    Follicular dendritic cells (FDCs) are unique immune cells that contribute to the regulation of humoral immune responses. These cells are located in the B-cell follicles of secondary lymphoid tissues where they trap and retain antigens (Ags) in the form of highly immunogenic immune complexes (ICs) consisting of Ag plus specific antibody (Ab) and/or complement proteins. FDCs multimerize Ags and present them polyvalently to B-cells in periodically arranged arrays that extensively crosslink the B-cell receptors for Ag (BCRs). FDC-FcγRIIB mediates IC periodicity, and FDC-Ag presentation combined with other soluble and membrane bound signals contributed by FDCs, like FDC-BAFF, -IL-6, and -C4bBP, are essential for the induction of the germinal center (GC) reaction, the maintenance of serological memory, and the remarkable ability of FDC-Ags to induce specific Ab responses in the absence of cognate T-cell help. On the other hand, FDCs play a negative role in several disease conditions including chronic inflammatory diseases, autoimmune diseases, HIV/AIDS, prion diseases, and follicular lymphomas. Compared to other accessory immune cells, FDCs have received little attention, and their functions have not been fully elucidated. This review gives an overview of FDC structure, and recapitulates our current knowledge on the immunoregulatory functions of FDCs in health and disease. A better understanding of FDCs should permit better regulation of Ab responses to suit the therapeutic manipulation of regulated and dysregulated immune responses. PMID:23049531

  9. [Dendritic cell-based therapeutic cancer vaccines].

    PubMed

    Rizzo, Manglio; Alaniz, Laura; Mazzolini, Guillermo D

    2016-01-01

    In recent years immunotherapy has revolutionized the treatment of patients with advanced cancer. The increased knowledge in the tumor immune-biology has allowed developing rational treatments by manipulation of the immune system with significant clinical impact. This rapid development has significantly changed the prognosis of many tumors without treatment options up to date. Other strategies have explored the use of therapeutic vaccines based on dendritic cells (DC) by inducing antitumor immunity. DC are cells of hematopoietic origin, constitutively expressing molecules capable to present antigens, that are functionally the most potent inducers of the activation and proliferation of antigen specific T lymphocytes. The CD8+ T cells proliferate and acquire cytotoxic capacity after recognizing their specific antigen presented on the surface of DC, although only some types of DC can present antigens internalized from outside the cell to precursors of cytotoxic T lymphocytes (this function is called cross-presentation) requiring translocation mechanisms of complex antigens. The induction of an effective adaptive immune response is considered a good option given its specificity, and prolonged duration of response. The DC, thanks to its particular ability of antigen presentation and lymphocyte stimulation, are able to reverse the poor antitumor immune response experienced by patients with cancer. The DC can be obtained from various sources, using different protocols to generate differentiation and maturation, and are administered by various routes such as subcutaneous, intravenous or intranodal. The wide variety of protocols resulted in heterogeneous clinical responses.

  10. Vaccination with TAT-antigen fusion protein induces protective, CD8(+) T cell-mediated immunity against Leishmania major.

    PubMed

    Kronenberg, Katharina; Brosch, Sven; Butsch, Florian; Tada, Yayoi; Shibagaki, Naotaka; Udey, Mark C; von Stebut, Esther

    2010-11-01

    In murine leishmaniasis, healing is mediated by IFN-γ-producing CD4(+) and CD8(+) T cells. Thus, an efficacious vaccine should induce Th1 and Tc1 cells. Dendritic cells (DCs) pulsed with exogenous proteins primarily induce strong CD4-dependent immunity; induction of CD8 responses has proven to be difficult. We evaluated the immunogenicity of fusion proteins comprising the protein transduction domain of HIV-1 TAT and the Leishmania antigen LACK (Leishmania homolog of receptors for activated C kinase), as TAT-fusion proteins facilitate major histocompatibility complex class I-dependent antigen presentation. In vitro, TAT-LACK-pulsed DCs induced stronger proliferation of Leishmania-specific CD8(+) T cells compared with DCs incubated with LACK alone. Vaccination with TAT-LACK-pulsed DCs or fusion proteins plus adjuvant in vivo significantly improved disease outcome in Leishmania major-infected mice and was superior to vaccination with DCs treated with LACK alone. Vaccination with DC+TAT-LACK resulted in stronger proliferation of CD8(+) T cells when compared with immunization with DC+LACK. Upon depletion of CD4(+) or CD8(+) T cells, TAT-LACK-mediated protection was lost. TAT-LACK-pulsed IL-12p40-deficient DCs did not promote protection in vivo. In summary, these data show that TAT-fusion proteins are superior in activating Leishmania-specific Tc1 cells when compared with antigen alone and suggest that IL-12-dependent preferential induction of antigen-specific CD8(+) cells promotes significant protection against this important human pathogen.

  11. Induction synchrotron

    NASA Astrophysics Data System (ADS)

    Takayama, Ken; Kishiro, Junichi

    2000-08-01

    A novel proton synchrotron employing induction cells instead of radio frequency cavities is proposed. The major feature of the barrier bucket acceleration, where acceleration and longitudinal focusing are independently achieved is theoretically discussed with the help of multi-particle simulations. It is proved that barrier bucket acceleration allows ultimate use of longitudinal phase-space and is quite effective to substantially increase the beam intensity in synchrotrons. Engineering aspects of key devices to realize the novel synchrotron, a ferri/ferro-magnetic material loaded induction cell and a modulator being rapidly switched in synchronization with beam acceleration are described in detail. The idea is applied to an existing machine (the KEK 12 GeV-PS) and high-intensity proton rings such as JHF, ESS, and SNS and their predicted improvement in machine performance is given with numerical values for each case.

  12. Earlier low-dose TBI or DST overcomes CD8+ T-cell-mediated alloresistance to allogeneic marrow in recipients of anti-CD40L.

    PubMed

    Takeuchi, Yasuo; Ito, Hiroshi; Kurtz, Josef; Wekerle, Thomas; Ho, Leon; Sykes, Megan

    2004-01-01

    Treatment with a single injection of anti-CD40L (CD154) monoclonal antibody (mAb) and fully mismatched allogeneic bone marrow transplant (BMT) allows rapid tolerization of CD4+ T cells to the donor. The addition of in vivo CD8 T-cell depletion leads to permanent mixed hematopoietic chimerism and tolerance. We now describe two approaches that obviate the requirement for CD8 T-cell depletion by rapidly tolerizing recipient CD8 T cells in addition to CD4 cells. Administration of donor-specific transfusion (DST) to mice receiving 3 Gy total body irradiation (TBI), BMT and anti-CD40L mAb on day 0 uniformly led to permanent mixed chimerism and tolerance, compared with only 40% of mice receiving similar treatment without DST. In the absence of DST, moving the timing of 3 Gy TBI to day -1 or day -2 instead of day 0 led to rapid (by 2 weeks) induction of CD8+ cell tolerance, and also permitted uniform achievement of permanent mixed chimerism and donor-specific tolerance in recipients of anti-CD40L and BMT on day 0. These nontoxic regimens overcome CD8+ and CD4+ T-cell-mediated alloresistance without requiring host T-cell depletion, permitting the induction of permanent mixed chimerism and tolerance.

  13. C-type lectin-like molecule-1 (CLL1)-targeted TRAIL augments the tumoricidal activity of granulocytes and potentiates therapeutic antibody-dependent cell-mediated cytotoxicity.

    PubMed

    Wiersma, Valerie R; de Bruyn, Marco; Shi, Ce; Gooden, Marloes J M; Wouters, Maartje C A; Samplonius, Douwe F; Hendriks, Djoke; Nijman, Hans W; Wei, Yunwei; Zhou, Jin; Helfrich, Wijnand; Bremer, Edwin

    2015-01-01

    The therapeutic effect of anti-cancer monoclonal antibodies stems from their capacity to opsonize targeted cancer cells with subsequent phagocytic removal, induction of antibody-dependent cell-mediated cytotoxicity (ADCC) or induction of complement-mediated cytotoxicity (CDC). The major immune effector cells involved in these processes are natural killer (NK) cells and granulocytes. The latter and most prevalent blood cell population contributes to phagocytosis, but is not effective in inducing ADCC. Here, we report that targeted delivery of the tumoricidal protein tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to granulocyte marker C-type lectin-like molecule-1 (CLL1), using fusion protein CLL1:TRAIL, equips granulocytes with high levels of TRAIL. Upon CLL1-selective binding of this fusion protein, granulocytes acquire additional TRAIL-mediated cytotoxic activity that, importantly, potentiates antibody-mediated cytotoxicity of clinically used therapeutic antibodies (e.g., rituximab, cetuximab). Thus, CLL1:TRAIL could be used as an adjuvant to optimize the clinical potential of anticancer antibody therapy by augmenting tumoricidal activity of granulocytes.

  14. Induction machine

    DOEpatents

    Owen, Whitney H.

    1980-01-01

    A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.

  15. Temporal synchrony and gamma to theta power conversion in the dendrites of CA1 pyramidal neurons

    PubMed Central

    Vaidya, Sachin P.; Johnston, Daniel

    2014-01-01

    Timing is a crucial aspect of synaptic integration. For pyramidal neurons that integrate thousands of synaptic inputs spread across hundreds of microns, it is thus a challenge to maintain the timing of incoming inputs at the axo-somatic integration site. Here we show that pyramidal neurons in the rodent hippocampus use a gradient of inductance in the form of HCN channels as an active mechanism to counteract location-dependent temporal differences of dendritic inputs at the soma. Using simultaneous multi-site whole cell recordings complemented by computational modeling, we find that this intrinsic biophysical mechanism produces temporal synchrony of rhythmic inputs in the theta and gamma frequency ranges across wide regions of the dendritic tree. While gamma and theta oscillations are known to synchronize activity across space in neuronal networks, our results identify a novel mechanism by which this synchrony extends to activity within single pyramidal neurons with complex dendritic arbors. PMID:24185428

  16. Dendritic cell analysis in primary immunodeficiency

    PubMed Central

    Bigley, Venetia; Barge, Dawn; Collin, Matthew

    2016-01-01

    Purpose of review Dendritic cells are specialized antigen-presenting cells which link innate and adaptive immunity, through recognition and presentation of antigen to T cells. Although the importance of dendritic cells has been demonstrated in many animal models, their contribution to human immunity remains relatively unexplored in vivo. Given their central role in infection, autoimmunity, and malignancy, dendritic cell deficiency or dysfunction would be expected to have clinical consequences. Recent findings Human dendritic cell deficiency disorders, related to GATA binding protein 2 (GATA2) and interferon regulatory factor 8 (IRF8) mutations, have highlighted the importance of dendritic cells and monocytes in primary immunodeficiency diseases and begun to shed light on their nonredundant roles in host defense and immune regulation in vivo. The contribution of dendritic cell and monocyte dysfunction to the pathogenesis of primary immunodeficiency disease phenotypes is becoming increasingly apparent. However, dendritic cell analysis is not yet a routine part of primary immunodeficiency disease workup. Summary Widespread uptake of dendritic cell/monocyte screening in clinical practice will facilitate the discovery of novel dendritic cell and monocyte disorders as well as advancing our understanding of human dendritic cell biology in health and disease. PMID:27755182

  17. Method of inhibiting dislocation generation in silicon dendritic webs

    DOEpatents

    Spitznagel, John A.; Seidensticker, Raymond G.; McHugh, James P.

    1990-11-20

    A method of tailoring the heat balance of the outer edge of the dendrites adjacent the meniscus to produce thinner, smoother dendrites, which have substantially less dislocation sources contiguous with the dendrites, by changing the view factor to reduce radiation cooling or by irradiating the dendrites with light from a quartz lamp or a laser to raise the temperature of the dendrites.

  18. Dendritic cells in Graves' disease.

    PubMed

    Purnamasari, Dyah; Soewondo, Pradana; Djauzi, Samsuridjal

    2015-01-01

    Dendritic cells are major antigen-presenting cells (APC) that stimulate naive T cells, which induce adaptive immune responses. Graves' disease (GD) is an autoimmune disease characterized by the presence of autoantibodies against Thyroid Stimulating Hormone Receptor (TSHR). The autoantibodies bind with TSHR and stimulate thyroid hormone production. Dendritic cells are still the major APC in GD immune response although thyrocytes in GD can also express Major Histocompatibility Class (MHC) class II molecule. Studies about DC in GD have been conducted by isolating intra-thyroid DC or DC in peripheral circulation. Results of DC studies in GD are still controversial. Changes in number and profile of DC are found, which indicate altered immune response activity and defects of regulator T cell (Treg) in GD.

  19. Dehydroeffusol effectively inhibits human gastric cancer cell-mediated vasculogenic mimicry with low toxicity

    SciTech Connect

    Liu, Wenming; Meng, Mei; Zhang, Bin; Du, Longsheng; Pan, Yanyan; Yang, Ping; Gu, Zhenlun; Zhou, Quansheng Cao, Zhifei

    2015-09-01

    Accumulated data has shown that various vasculogenic tumor cells, including gastric cancer cells, are able to directly form tumor blood vessels via vasculogenic mimicry, supplying oxygen and nutrients to tumors, and facilitating progression and metastasis of malignant tumors. Therefore, tumor vasculogenic mimicry is a rational target for developing novel anticancer therapeutics. However, effective antitumor vasculogenic mimicry-targeting drugs are not clinically available. In this study, we purified 2,7-dihydroxyl-1-methyl-5-vinyl-phenanthrene, termed dehydroeffusol, from the traditional Chinese medicinal herb Juncus effusus L., and found that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry in vitro and in vivo with very low toxicity. Dehydroeffusol significantly suppressed gastric cancer cell adhesion, migration, and invasion. Molecular mechanistic studies revealed that dehydroeffusol markedly inhibited the expression of a vasculogenic mimicry master gene VE-cadherin and reduced adherent protein exposure on the cell surface by inhibiting gene promoter activity. In addition, dehydroeffusol significantly decreased the expression of a key vasculogenic gene matrix metalloproteinase 2 (MMP2) in gastric cancer cells, and diminished MMP2 protease activity. Together, our results showed that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry with very low toxicity, suggesting that dehydroeffusol is a potential drug candidate for anti-gastric cancer neovascularization and anti-gastric cancer therapy. - Highlights: • Dehydroeffusol markedly inhibits gastric cancer cell-mediated vasculogenic mimicry. • Dehydroeffusol suppresses the expression of vasculogenic mimicry key gene VE-cadherin. • Dehydroeffusol decreases the MMP2 expression and activity in gastric cancer cells. • Dehydroeffusol is a potential anti-cancer drug candidate with very low toxicity.

  20. Ornamental comb colour predicts T-cell-mediated immunity in male red grouse Lagopus lagopus scoticus

    NASA Astrophysics Data System (ADS)

    Mougeot, Francois

    2008-02-01

    Sexual ornaments might reliably indicate the ability to cope with parasites and diseases, and a better ability to mount a primary inflammatory response to a novel challenge. Carotenoid-based ornaments are amongst the commonest sexual signals of birds and often influence mate choice. Because carotenoids are immuno-stimulants, signallers may trade-off allocating these to ornamental colouration or using them for immune responses, so carotenoid-based ornaments might be particularly useful as honest indicators of immuno-compentence. Tetraonid birds, such as the red grouse Lagopus lagopus scoticus, exhibit supra-orbital yellow red combs, a conspicuous ornament which functions in intra- and inter-sexual selection. The colour of combs is due to epidermal pigmentation by carotenoids, while their size is testosterone-dependent. In this study, I investigated whether comb characteristics, and in particular, comb colour, indicated immuno-competence in free-living male red grouse. I assessed T-cell-mediated immunity using a standardised challenge with phytohaemagglutinin. Red grouse combs reflect in the red and in the ultraviolet spectrum of light, which is not visible to humans but that grouse most likely see, so I measured comb colour across the whole bird visible spectrum (300 700 nm) using a reflectance spectrometer. I found that males with bigger and redder combs, but with less ultraviolet reflectance, had greater T-cell-mediated immune response. Comb colour predicted T-cell-mediated immune response better than comb size, indicating that the carotenoid-based colouration of this ornament might reliably signal this aspect of male quality.

  1. Cell mediated immunity after measles in Guinea-Bissau: historical cohort study.

    PubMed Central

    Shaheen, S. O.; Aaby, P.; Hall, A. J.; Barker, D. J.; Heyes, C. B.; Shiell, A. W.; Goudiaby, A.

    1996-01-01

    OBJECTIVE: To investigate whether children who have had measles have reduced general cell mediated immunity three years later compared with vaccinated children who have not had measles. DESIGN: Historical cohort study. SETTING: Bissau, Guinea-Bissau. SUBJECTS: 391 children aged 3-13 years who were living in Bissau during a measles epidemic in 1991 and still lived there. These included 131 primary cases and 139 secondary cases from the epidemic and 121 vaccinated controls with no history of measles. MAIN OUTCOME MEASURES: General cell mediated immunity assessed by measurement of delayed type hypersensitivity skin responses to seven recall antigens. Anergy was defined as a lack of response to all antigens. RESULTS: 82 out of 268 cases of measles (31%) were anergic compared with 20 of the 121 vaccinated controls (17%) (odds ratio adjusted for potential confounding variables 2.2 (95% confidence interval 1.2 to 4.0); P 0.009). The prevalence of anergy was higher in secondary cases (33% (46/138)) than in primary cases (28% (36/130)), although this difference was not significant. Anergy was more common in the rainy season (unadjusted prevalence 31% (91/291) than in the dry season (11% (11/98)) (adjusted odds ratio 4.8 (2.2 to 10.3)). This seasonal increase occurred predominantly in the case of measles. CONCLUSION: Reduced general cell mediated immunity may contribute to the higher long term mortality in children who have had measles compared with recipients of standard measles vaccine and to the higher child mortality in the rainy season in west Africa. PMID:8892416

  2. Ornamental comb colour predicts T-cell-mediated immunity in male red grouse Lagopus lagopus scoticus.

    PubMed

    Mougeot, Francois

    2008-02-01

    Sexual ornaments might reliably indicate the ability to cope with parasites and diseases, and a better ability to mount a primary inflammatory response to a novel challenge. Carotenoid-based ornaments are amongst the commonest sexual signals of birds and often influence mate choice. Because carotenoids are immuno-stimulants, signallers may trade-off allocating these to ornamental colouration or using them for immune responses, so carotenoid-based ornaments might be particularly useful as honest indicators of immuno-compentence. Tetraonid birds, such as the red grouse Lagopus lagopus scoticus, exhibit supra-orbital yellow-red combs, a conspicuous ornament which functions in intra- and inter-sexual selection. The colour of combs is due to epidermal pigmentation by carotenoids, while their size is testosterone-dependent. In this study, I investigated whether comb characteristics, and in particular, comb colour, indicated immuno-competence in free-living male red grouse. I assessed T-cell-mediated immunity using a standardised challenge with phytohaemagglutinin. Red grouse combs reflect in the red and in the ultraviolet spectrum of light, which is not visible to humans but that grouse most likely see, so I measured comb colour across the whole bird visible spectrum (300-700 nm) using a reflectance spectrometer. I found that males with bigger and redder combs, but with less ultraviolet reflectance, had greater T-cell-mediated immune response. Comb colour predicted T-cell-mediated immune response better than comb size, indicating that the carotenoid-based colouration of this ornament might reliably signal this aspect of male quality.

  3. The PHA Test Reflects Acquired T-Cell Mediated Immunocompetence in Birds

    PubMed Central

    Tella, José L.; Lemus, Jesús A.; Carrete, Martina; Blanco, Guillermo

    2008-01-01

    Background cological immunology requires techniques to reliably measure immunocompetence in wild vertebrates. The PHA-skin test, involving subcutaneous injection of a mitogen (phytohemagglutinin, PHA) and measurement of subsequent swelling as a surrogate of T-cell mediated immunocompetence, has been the test of choice due to its practicality and ease of use in the field. However, mechanisms involved in local immunological and inflammatory processes provoked by PHA are poorly known, and its use and interpretation as an acquired immune response is currently debated. Methodology Here, we present experimental work using a variety of parrot species, to ascertain whether PHA exposure produces larger secondary than primary responses as expected if the test reflects acquired immunocompetence. Moreover, we simultaneously quantified T-lymphocyte subsets (CD4+, CD5+ and CD8+) and plasma proteins circulating in the bloodstream, potentially involved in the immunological and inflammatory processes, through flow cytometry and electrophoresis. Principal Findings Our results showed stronger responses after a second PHA injection, independent of species, time elapsed and changes in body mass of birds between first and second injections, thus supporting the adaptive nature of this immune response. Furthermore, the concomitant changes in the plasma concentrations of T-lymphocyte subsets and globulins indicate a causal link between the activation of the T-cell mediated immune system and local tissue swelling. Conclusions/Significance These findings justify the widespread use of the PHA-skin test as a reliable evaluator of acquired T-cell mediated immunocompetence in diverse biological disciplines. Further experimental research should be aimed at evaluating the relative role of innate immunocompetence in wild conditions, where the access to dietary proteins varies more than in captivity, and to ascertain how PHA responses relate to particular host-parasite interactions. PMID:18820730

  4. A DEPRESSION OF CELL-MEDIATED IMMUNITY TO MEASLES ANTIGEN IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

    PubMed Central

    Utermohlen, Virginia; Winfield, John B.; Zabriskie, John B.; Kunkel, Henry G.

    1974-01-01

    Using the direct migration inhibition test, response to measles antigen in patients with systemic lupus erythematosus (SLE) was found to be decreased when compared with that of normal subjects. No alteration was observed in similar experiments using parainfluenza type 1 and rubella antigens. The specific decrease in measles antigen effect showed no obvious correlation with activity of SLE or with the presence of lymphocytotoxic antibodies. Whether the specificity of the decrease in reactivity is due to some particular relationship between the measles virus or antigen and SLE, or to the possibility that measles reactivity is a more sensitive indicator of a generalized defect of cell-mediated immunity, remains unclear. PMID:4361242

  5. Essential oil of clove (Eugenia caryophyllata) augments the humoral immune response but decreases cell mediated immunity.

    PubMed

    Halder, Sumita; Mehta, Ashish K; Mediratta, Pramod K; Sharma, Krishna K

    2011-08-01

    The present study was undertaken to explore the effect of the essential oil isolated from the buds of Eugenia caryophyllata on some immunological parameters. Humoral immunity was assessed by measuring the hemagglutination titre to sheep red blood cells and delayed type hypersensitivity was assessed by measuring foot pad thickness. Clove oil administration produced a significant increase in the primary as well as secondary humoral immune response. In addition, it also produced a significant decrease in foot pad thickness compared with the control group. Thus, these results suggest that clove oil can modulate the immune response by augmenting humoral immunity and decreasing cell mediated immunity.

  6. Dendritic web silicon for solar cell application

    NASA Technical Reports Server (NTRS)

    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.

  7. Active Dendrites Enhance Neuronal Dynamic Range

    PubMed Central

    Gollo, Leonardo L.; Kinouchi, Osame; Copelli, Mauro

    2009-01-01

    Since the first experimental evidences of active conductances in dendrites, most neurons have been shown to exhibit dendritic excitability through the expression of a variety of voltage-gated ion channels. However, despite experimental and theoretical efforts undertaken in the past decades, the role of this excitability for some kind of dendritic computation has remained elusive. Here we show that, owing to very general properties of excitable media, the average output of a model of an active dendritic tree is a highly non-linear function of its afferent rate, attaining extremely large dynamic ranges (above 50 dB). Moreover, the model yields double-sigmoid response functions as experimentally observed in retinal ganglion cells. We claim that enhancement of dynamic range is the primary functional role of active dendritic conductances. We predict that neurons with larger dendritic trees should have larger dynamic range and that blocking of active conductances should lead to a decrease in dynamic range. PMID:19521531

  8. Cell-intrinsic drivers of dendrite morphogenesis.

    PubMed

    Puram, Sidharth V; Bonni, Azad

    2013-12-01

    The proper formation and morphogenesis of dendrites is fundamental to the establishment of neural circuits in the brain. Following cell cycle exit and migration, neurons undergo organized stages of dendrite morphogenesis, which include dendritic arbor growth and elaboration followed by retraction and pruning. Although these developmental stages were characterized over a century ago, molecular regulators of dendrite morphogenesis have only recently been defined. In particular, studies in Drosophila and mammalian neurons have identified numerous cell-intrinsic drivers of dendrite morphogenesis that include transcriptional regulators, cytoskeletal and motor proteins, secretory and endocytic pathways, cell cycle-regulated ubiquitin ligases, and components of other signaling cascades. Here, we review cell-intrinsic drivers of dendrite patterning and discuss how the characterization of such crucial regulators advances our understanding of normal brain development and pathogenesis of diverse cognitive disorders.

  9. Dendritic NMDA spikes are necessary for timing-dependent associative LTP in CA3 pyramidal cells

    PubMed Central

    Brandalise, Federico; Carta, Stefano; Helmchen, Fritjof; Lisman, John; Gerber, Urs

    2016-01-01

    The computational repertoire of neurons is enhanced by regenerative electrical signals initiated in dendrites. These events, referred to as dendritic spikes, can act as cell-intrinsic amplifiers of synaptic input. Among these signals, dendritic NMDA spikes are of interest in light of their correlation with synaptic LTP induction. Because it is not possible to block NMDA spikes pharmacologically while maintaining NMDA receptors available to initiate synaptic plasticity, it remains unclear whether NMDA spikes alone can trigger LTP. Here we use dendritic recordings and calcium imaging to analyse the role of NMDA spikes in associative LTP in CA3 pyramidal cells. We show that NMDA spikes produce regenerative branch-specific calcium transients. Decreasing the probability of NMDA spikes reduces LTP, whereas increasing their probability enhances LTP. NMDA spikes and LTP occur without back-propagating action potentials. However, action potentials can facilitate LTP induction by promoting NMDA spikes. Thus, NMDA spikes are necessary and sufficient to produce the critical postsynaptic depolarization required for associative LTP in CA3 pyramidal cells. PMID:27848967

  10. The Equiaxed Dendritic Solidification Experiment (EDSE)

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Equiaxed Dendritic Solidification Experiment (EDSE) is a material sciences investigation under the Formation of Microstructures/pattern formation discipline. The objective is to study the microstructural evolution of and thermal interactions between several equiaxed crystals growing dendritically in a supercooled melt of a pure and transparent substance under diffusion controlled conditions. Dendrites growing at .4 supercooling from a 2 stinger growth chamber for the EDSE in the Microgravity Development Lab (MDL).

  11. Orientations of dendritic growth during solidification

    NASA Astrophysics Data System (ADS)

    Lee, Dong Nyung

    2017-02-01

    Dendrites are crystalline forms which grow far from the limit of stability of the plane front and adopt an orientation which is as close as possible to the heat flux direction. Dendritic growth orientations for cubic metals, bct Sn, and hcp Zn, can be controlled by thermal conductivity, Young's modulus, and surface energy. The control factors have been elaborated. Since the dendrite is a single crystal, its properties such as thermal conductivity that influences the heat flux direction, the minimum Young's modulus direction that influences the strain energy minimization, and the minimum surface energy plane that influences the crystal/liquid interface energy minimization have been proved to control the dendritic growth direction. The dendritic growth directions of cubic metals are determined by the minimum Young's modulus direction and/or axis direction of symmetry of the minimum crystal surface energy plane. The dendritic growth direction of bct Sn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction. The primary dendritic growth direction of hcp Zn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction and the secondary dendrite arm direction of hcp Zn is normal to the primary dendritic growth direction.

  12. Dendrite preventing separator for secondary lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, David H. (Inventor); Surampudi, Subbarao (Inventor); Huang, Chen-Kuo (Inventor); Halpert, Gerald (Inventor)

    1993-01-01

    Dendrites are prevented from shorting a secondary lithium battery by use of a first porous separator, such as porous polypropylene, adjacent to the lithium anode that is unreactive with lithium and a second porous fluoropolymer separator between the cathode and the first separator, such as polytetrafluoroethylene, that is reactive with lithium. As the tip of a lithium dendrite contacts the second separator, an exothermic reaction occurs locally between the lithium dendrite and the fluoropolymer separator. This results in the prevention of the dendrite propagation to the cathode.

  13. Dendrite preventing separator for secondary lithium batteries

    NASA Technical Reports Server (NTRS)

    Shen, David H. (Inventor); Surampudi, Subbarao (Inventor); Huang, Chen-Kuo (Inventor); Halpert, Gerald (Inventor)

    1995-01-01

    Dendrites are prevented from shorting a secondary lithium battery by use of a first porous separator such as porous polypropylene adjacent the lithium anode that is unreactive with lithium and a second porous fluoropolymer separator between the cathode and the first separator such as polytetrafluoroethylene that is reactive with lithium. As the tip of a lithium dendrite contacts the second separator, an exothermic reaction occurs locally between the lithium dendrite and the fluoropolymer separator. This results in the prevention of the dendrite propagation to the cathode.

  14. Orientations of dendritic growth during solidification

    NASA Astrophysics Data System (ADS)

    Lee, Dong Nyung

    2017-03-01

    Dendrites are crystalline forms which grow far from the limit of stability of the plane front and adopt an orientation which is as close as possible to the heat flux direction. Dendritic growth orientations for cubic metals, bct Sn, and hcp Zn, can be controlled by thermal conductivity, Young's modulus, and surface energy. The control factors have been elaborated. Since the dendrite is a single crystal, its properties such as thermal conductivity that influences the heat flux direction, the minimum Young's modulus direction that influences the strain energy minimization, and the minimum surface energy plane that influences the crystal/liquid interface energy minimization have been proved to control the dendritic growth direction. The dendritic growth directions of cubic metals are determined by the minimum Young's modulus direction and/or axis direction of symmetry of the minimum crystal surface energy plane. The dendritic growth direction of bct Sn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction. The primary dendritic growth direction of hcp Zn is determined by its maximum thermal conductivity direction and the minimum surface energy plane normal direction and the secondary dendrite arm direction of hcp Zn is normal to the primary dendritic growth direction.

  15. Intravital imaging of dendritic spine plasticity

    PubMed Central

    Sau Wan Lai, Cora

    2014-01-01

    Abstract Dendritic spines are the postsynaptic part of most excitatory synapses in the mammalian brain. Recent works have suggested that the structural and functional plasticity of dendritic spines have been associated with information coding and memories. Advances in imaging and labeling techniques enable the study of dendritic spine dynamics in vivo. This perspective focuses on intravital imaging studies of dendritic spine plasticity in the neocortex. I will introduce imaging tools for studying spine dynamics and will further review current findings on spine structure and function under various physiological and pathological conditions. PMID:28243511

  16. The renal microenvironment modifies dendritic cell phenotype.

    PubMed

    Chessa, Federica; Mathow, Daniel; Wang, Shijun; Hielscher, Thomas; Atzberger, Ann; Porubsky, Stefan; Gretz, Norbert; Burgdorf, Sven; Gröne, Hermann-Josef; Popovic, Zoran V

    2016-01-01

    Renal dendritic cells are a major component of the renal mononuclear phagocytic system. In the renal interstitium, these cells are exposed to an osmotic gradient, mainly sodium, whose concentration progressively increases towards inner medulla. Renal allograft rejection affects predominantly the cortex, suggesting a protective role of the renal medullary micromilieu. Whether osmolar variations can modulate the function of renal dendritic cells is currently undefined. Considering the central role of dendritic cells in promoting allorejection, we tested whether the biophysical micromilieu, particularly the interstitial osmotic gradient, influences their alloreactivity. There was a progressive depletion of leukocytes towards the medulla of homeostatic kidney. Only macrophages opposed this tendency. Flow cytometry of homeostatic and post-transplant medullary dendritic cells revealed a switch towards a macrophage-like phenotype. Similarly, bone marrow-derived dendritic cells developed ex vivo in sodium chloride-enriched medium acquired a M2-like signature. Microarray analysis of allotransplant dendritic cells posed a medullary downregulation of genes mainly involved in alloantigen recognition. Gene expression profiles of both medullary dendritic cells and bone marrow-derived dendritic cells matured in hyperosmolar medium had an overlap with the macrophage M2 signature. Thus, the medullary environment inhibits an alloimmune response by modulating the phenotype and function of dendritic cells.

  17. Precipitation dendrites in turbulent pipe flows

    NASA Astrophysics Data System (ADS)

    Angheluta, Luiza; Hawkins, Christopher; Hammer, Øyvind; Jamtveit, Bjørn

    2013-04-01

    Surface precipitation in pipelines, as well as freezing in water pipes is of great concern in many industrial applications where scaling phenomena becomes a control problem of pipe-clogging or an efficiency reduction in transport. Flow blockage often occurs even when only a small fraction is deposited non-uniformly on the walls in the form of dendrites. Dendritic patterns are commonly encountered in surface precipitation from supersaturated solutions, e.g. calcite dendrites, as well as in solidification from undercooled liquids, e.g. freezing of water into ice dendrites. We explore the mathematical similarities between precipitation and freezing processes and, in particular, investigate the effect of fluid flow on the precipitation dendrites on pipe walls. We use a phase field approach to model surface growth coupled with a lattice Boltzmann method that simulates a channel flow at varying Reynolds number. The dendrites orientation and shape depend non-trivially on the ratio between advection and diffusion, i.e. the Peclet number, as well as the Reynolds number. Roughness induced vortices near growing dendrites at high flow rates further affect the branch splitting of dendrites. We show how the transport rate in a pipeline may depend on the different dendritic morphologies, and provide estimates for the flow conditions that correspond to most efficient transport regimes.

  18. Novel mathematical models for cell-mediated cytotoxicity assays without applying enzyme kinetics but with combinations and probability: bystanders in bulk effector cells influence results of cell-mediated cytotoxicity assays.

    PubMed

    Takayanagi, Toshiaki

    2011-07-01

    Cell-mediated cytotoxicity assays are widely implemented to evaluate cell-mediated cytotoxic activity, and some assays are analyzed using the analogy of enzyme kinetics. In the analogy, the effector cell is regarded as the enzyme, the target cell as the substrate, the effector cell-target cell conjugate as the enzyme-substrate complex and the dead target cell as the product. However, the assumptions analogous to those of enzyme kinetics are not always true in cell-mediated cytotoxicity assays, and the parameter analogous to the Michaelis-Menten constant is not constant but is dependent on the number of effector cells. Therefore I present novel mathematical models for cell-mediated cytotoxicity assays without applying enzyme kinetics. I instead use combinations and probability, because analysis of cell-mediated cytotoxicity assays by applying enzyme kinetics seems controversial. With my original models, I demonstrate simulations of the data in previously published papers. The results are exhibited in the same forms as the corresponding data. Comparing the simulation results with the published data, the results seem to agree well with the data. From simulations of cytotoxic assays with bulk effector cells, it appears that bystanders in bulk effector cells increase both the cytotoxic activity and the motility of effector cells.

  19. Stephanthraniline A suppressed CD4(+) T cell-mediated immunological hepatitis through impairing PKCθ function.

    PubMed

    Chen, Feng-Yang; Zhou, Li-Fei; Li, Xiao-Yu; Zhao, Jia-Wen; Xu, Shi-Fang; Huang, Wen-Hai; Gao, Li-Juan; Hao, Shu-Juan; Ye, Yi-Ping; Sun, Hong-Xiang

    2016-10-15

    Stephanthraniline A (STA), a C21 steroid isolated from Stephanotis mucronata (Blanco) Merr., was previously shown to inhibit T cells activation and proliferation in vitro and in vivo. The purpose of this study was to further evaluate the in vivo immunosuppressive activity of STA and to elucidate its potential mechanisms. The results showed that pretreatment with STA significantly attenuated concanavalin A (Con A)-induced hepatitis and reduced CD4(+) T cells activation and aggregation in hepatic tissue in mice. STA directly suppressed the activation and proliferation of Con A-induced CD4(+) T cells, and inhibited NFAT, NFκB and MAPK signaling cascades in activated CD4(+) T cells in vitro. Moreover, it was proved that STA inhibited T cells activation and proliferation through proximal T cell-receptor (TCR) signaling- and Ca(2+) signaling-independent way. The molecular docking studies predicted that STA could tight bind to PKCθ via five hydrogen. The further findings indicated STA directly inhibited PKCθ kinase activity, and its phosphorylation in activated CD4(+) T cells in vitro. Collectively, the present study indicated that STA could protect against CD4(+) T cell-mediated immunological hepatitis in mice through PKCθ and its downstream NFAT, NFκB and MAPK signaling cascades. These results highlight the potential of STA as an effective leading compound for use in the treatment of CD4(+) T cell-mediated inflammatory and autoimmune diseases.

  20. Dehydroeffusol effectively inhibits human gastric cancer cell-mediated vasculogenic mimicry with low toxicity.

    PubMed

    Liu, Wenming; Meng, Mei; Zhang, Bin; Du, Longsheng; Pan, Yanyan; Yang, Ping; Gu, Zhenlun; Zhou, Quansheng; Cao, Zhifei

    2015-09-01

    Accumulated data has shown that various vasculogenic tumor cells, including gastric cancer cells, are able to directly form tumor blood vessels via vasculogenic mimicry, supplying oxygen and nutrients to tumors, and facilitating progression and metastasis of malignant tumors. Therefore, tumor vasculogenic mimicry is a rational target for developing novel anticancer therapeutics. However, effective antitumor vasculogenic mimicry-targeting drugs are not clinically available. In this study, we purified 2,7-dihydroxyl-1-methyl-5-vinyl-phenanthrene, termed dehydroeffusol, from the traditional Chinese medicinal herb Juncus effusus L., and found that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry in vitro and in vivo with very low toxicity. Dehydroeffusol significantly suppressed gastric cancer cell adhesion, migration, and invasion. Molecular mechanistic studies revealed that dehydroeffusol markedly inhibited the expression of a vasculogenic mimicry master gene VE-cadherin and reduced adherent protein exposure on the cell surface by inhibiting gene promoter activity. In addition, dehydroeffusol significantly decreased the expression of a key vasculogenic gene matrix metalloproteinase 2 (MMP2) in gastric cancer cells, and diminished MMP2 protease activity. Together, our results showed that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry with very low toxicity, suggesting that dehydroeffusol is a potential drug candidate for anti-gastric cancer neovascularization and anti-gastric cancer therapy.

  1. HLA-B8 and cell-mediated immunity to gluten.

    PubMed Central

    Simpson, F G; Bullen, A W; Robertson, D A; Losowsky, M S

    1981-01-01

    The leucocyte migration inhibition (LMI) test was used as an indicator of cell mediated immunity to gluten fraction III in 30 healthy controls and 58 patients with adult coeliac disease and the results related to HLA status and duration of treatment with a gluten-free diet. HLA-B8 controls showed significantly lower leucocyte migration indices, indicating greater immune response, than non-HLA B8 controls. Untreated coeliacs showed no difference from HLA-B8 controls. There was no difference between results from HLA-B8 and non-HLA-B8 coeliacs. Leucocyte migration was even lower in coeliacs early in treatment but rose after treatment for over one year. These results may reflect an immune response gene for gluten in linkage disequilibrium with HLA-B8. The increased immune response to gluten as measured in this test cannot be the sole factor in aetiology of coeliac disease. Furthermore, it is necessary to re-evaluate earlier results of cell-mediated immunity in coeliac disease with reference to HLA status of the controls. PMID:6974678

  2. Design strategies and applications of circulating cell-mediated drug delivery systems

    PubMed Central

    Kim, Gloria B.; Dong, Cheng; Yang, Jian

    2015-01-01

    Drug delivery systems, particularly nanomaterial-based drug delivery systems, possess a tremendous amount of potential to improve diagnostic and therapeutic effects of drugs. Controlled drug delivery targeted to a specific disease is designed to significantly improve the pharmaceutical effects of drugs and reduce their side effects. Unfortunately, only a few targeted drug delivery systems can achieve high targeting efficiency after intravenous injection, even with the development of numerous surface markers and targeting modalities. Thus, alternative drug and nanomedicine targeting approaches are desired. Circulating cells, such as erythrocytes, leukocytes, and stem cells, present innate disease sensing and homing properties. Hence, using living cells as drug delivery carriers has gained increasing interest in recent years. This review highlights the recent advances in the design of cell-mediated drug delivery systems and targeting mechanisms. The approaches of drug encapsulation/conjugation to cell-carriers, cell-mediated targeting mechanisms, and the methods of controlled drug release are elaborated here. Cell-based “live” targeting and delivery could be used to facilitate a more specific, robust, and smart payload distribution for the next-generation drug delivery systems. PMID:25984572

  3. The role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair.

    PubMed

    Saparov, Arman; Chen, Chien-Wen; Beckman, Sarah A; Wang, Yadong; Huard, Johnny

    2013-08-06

    Oxidative stress and inflammation play major roles in the pathogenesis of coronary heart disease including myocardial infarction (MI). The pathological progression following MI is very complex and involves a number of cell populations including cells localized within the heart, as well as cells recruited from the circulation and other tissues that participate in inflammatory and reparative processes. These cells, with their secretory factors, have pleiotropic effects that depend on the stage of inflammation and regeneration. Excessive inflammation leads to enlargement of the infarction site, pathological remodeling and eventually, heart dysfunction. Stem cell therapy represents a unique and innovative approach to ameliorate oxidative stress and inflammation caused by ischemic heart disease. Consequently, it is crucial to understand the crosstalk between stem cells and other cells involved in post-MI cardiac tissue repair, especially immune cells, in order to harness the beneficial effects of the immune response following MI and further improve stem cell-mediated cardiac regeneration. This paper reviews the recent findings on the role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair following ischemic heart disease, particularly acute MI and focuses specifically on mesenchymal, muscle and blood-vessel-derived stem cells due to their antioxidant and immunomodulatory properties.

  4. Regulation of herpes simplex virus-specific cell-mediated immunity by a specific suppressor factor.

    PubMed Central

    Horohov, D W; Wyckoff, J H; Moore, R N; Rouse, B T

    1986-01-01

    Our study was designed to investigate the nature of an antigen-specific suppressor factor generated by antigen-stimulated herpes simplex virus (HSV)-immune splenocytes. Factor SF-200, a 90,000- to 100,000-dalton fraction obtained after Sephacryl gel filtration, suppressed the generation of HSV-specific cytotoxic T-lymphocyte and lymphoproliferative responses. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of SF-200 indicated that it contained an I-J+, anti-idiotypic protein. It was possible to adsorb the suppressor activity of SF-200 to an anti-I-J immunoaffinity column. The suppressor activity could be eluted from the immunoaffinity column with a low-pH buffer. The acid-eluted material was determined to be both I-J+ and reactive with anti-HSV antiserum by Western blot analysis. Both SF-200 and the I-J+ suppressor activity suppressed only HSV-specific cell-mediated immunity responses. However, it was possible to generate nonspecific suppressor activity by incubating the I-J+ suppressor factor with Lyt 1+ splenocytes from HSV-immune mice. The implication of these results with respect to the model for a suppressor cell circuit regulating HSV-specific cell-mediated immunity responses is discussed. Images PMID:3009850

  5. ITIM-dependent negative signaling pathways for the control of cell-mediated xenogeneic immune responses.

    PubMed

    del Rio, Maria-Luisa; Seebach, Jörg D; Fernández-Renedo, Carlos; Rodriguez-Barbosa, Jose-Ignacio

    2013-01-01

    Xenotransplantation is an innovative field of research with the potential to provide us with an alternative source of organs to face the severe shortage of human organ donors. For several reasons, pigs have been chosen as the most suitable source of organs and tissues for transplantation in humans. However, porcine xenografts undergo cellular immune responses representing a major barrier to their acceptance and normal functioning. Innate and adaptive xenogeneic immunity is mediated by both the recognition of xenogeneic tissue antigens and the lack of inhibition due to molecular cross-species incompatibilities of regulatory pathways. Therefore, the delivery of immunoreceptor tyrosine-based inhibitory motif (ITIM)-dependent and related negative signals to control innate (NK cells, macrophages) and adaptive T and B cells might overcome cell-mediated xenogeneic immunity. The proof of this concept has already been achieved in vitro by the transgenic overexpression of human ligands of several inhibitory receptors in porcine cells resulting in their resistance against xenoreactivity. Consequently, several transgenic pigs expressing tissue-specific human ligands of inhibitory coreceptors (HLA-E, CD47) or soluble competitors of costimulation (belatacept) have already been generated. The development of these robust and innovative approaches to modulate human anti-pig cellular immune responses, complementary to conventional immunosuppression, will help to achieve long-term xenograft survival. In this review, we will focus on the current strategies to enhance negative signaling pathways for the regulation of undesirable cell-mediated xenoreactive immune responses.

  6. Cordyceps militaris Enhances Cell-Mediated Immunity in Healthy Korean Men.

    PubMed

    Kang, Ho Joon; Baik, Hyun Wook; Kim, Sang Jung; Lee, Seong Gyu; Ahn, Hong Yup; Park, Ju Sang; Park, Sang Jong; Jang, Eun Jeong; Park, Sang Woon; Choi, Jin Young; Sung, Ji Hee; Lee, Seung Min

    2015-10-01

    Cordyceps militaris is a mushroom traditionally used for diverse pharmaceutical purposes in East Asia, including China, and has been found to be effective for enhancing immunity through various types of animal testing. The aim of this study is to determine the efficacy of C. militaris for enhancing cell-mediated immunity and its safety in healthy male adults. Healthy male adults were divided into the experimental group (n = 39), given 1.5 g/day of ethanol treated C. militaris in capsules, and the control group (n = 40), given the same number of identical placebo capsules filled with microcrystalline cellulose and lactose for 4 weeks from February 13 to March 14, 2012; the natural killer (NK) cell activity, lymphocyte proliferation index (PI), and T-helper cell 1 (Th1) cytokine cluster (interferon [IFN]-γ, interleukin [IL]-12, IL-2, and tumor necrosis factor [TNF]-α) were measured, along with stability test, at weeks 0, 2, and 4. The C. militaris group showed a statistically significant greater increase in NK200 (P = .0010), lymphocyte PI (P ≤ .0001), IL-2 (P = .0096), and IFN-γ (P = .0126), compared with the basal level, than the placebo group. There was no statistically significant adverse reaction. C. militaris enhanced the NK cell activity and lymphocyte proliferation and partially increased Th1 cytokine secretion. Therefore, C. militaris is safe and effective for enhancing cell-mediated immunity of healthy male adults.

  7. In vitro enhancement of human natural cell-mediated cytotoxicity by purified influenza virus glycoproteins.

    PubMed Central

    Arora, D J; Houde, M; Justewicz, D M; Mandeville, R

    1984-01-01

    The role of the glycoproteins of influenza virus, hemagglutinin (HA), and neuraminidase (NA) in the in vitro stimulation of natural cell-mediated cytotoxicity (NCMC) or natural killer activity of human peripheral blood lymphocytes was evaluated with radiolabeled K562 cells as target cells in an overnight chromium release assay. Three different approaches were used. (i) Purified viral proteins were obtained by extraction with Nonidet P-40, separation on a sucrose gradient, and further purification by affinity chromatography. Ficoll-Hypaque-purified peripheral blood lymphocytes exposed to HA or NA individually or to a mixture of both significantly increased NCMC (32 to 50%). (ii) Treatment of HA and NA with their respective homologous antisera or F(ab')2 antibody abrogated the stimulation of NCMC by these glycoproteins. (iii) Virions treated with proteolytic enzymes resulted in viral cores lacking either HA or NA or both activities. Compared to whole virions, viral cores devoid of HA activity only induced a 50% increase in NCMC, whereas viral cores lacking HA activity and with traces of NA activity stimulated only 10% of the NCMC. These results suggest that influenza virus-induced cell-mediated cytotoxicity is largely due to its glycoproteins. PMID:6387178

  8. Monocyte-derived dendritic cells identified as booster of T follicular helper cell differentiation

    PubMed Central

    Fillatreau, Simon

    2014-01-01

    Adjuvants play an essential role in the induction of acquired immunity upon vaccination with protein antigen. In this issue of EMBO Molecular Medicine, a classical type of adjuvant made of DNA oligonucleotide containing CpG motifs, which has already been used in humans, is shown to boost humoral immunity primarily by acting on monocyte-derived dendritic cells. This study provides novel insight on the mode of action of adjuvant targeting Toll-like receptors. PMID:24803394

  9. The Impact of HLA Class I-Specific Killer Cell Immunoglobulin-Like Receptors on Antibody-Dependent Natural Killer Cell-Mediated Cytotoxicity and Organ Allograft Rejection

    PubMed Central

    Rajalingam, Raja

    2016-01-01

    Natural killer (NK) cells of the innate immune system are cytotoxic lymphocytes that play an important roles following transplantation of solid organs and hematopoietic stem cells. Recognition of self-human leukocyte antigen (HLA) class I molecules by inhibitory killer cell immunoglobulin-like receptors (KIRs) is involved in the calibration of NK cell effector capacities during the developmental stage, allowing the subsequent recognition and elimination of target cells with decreased expression of self-HLA class I (due to virus infection or tumor transformation) or HLA class I disparities (in the setting of allogeneic transplantation). NK cells expressing an inhibitory KIR-binding self-HLA can be activated when confronted with allografts lacking a ligand for the inhibitory receptor. Following the response of the adaptive immune system, NK cells can further destroy allograft endothelium by antibody-dependent cell-mediated cytotoxicity (ADCC), triggered through cross-linking of the CD16 Fc receptor by donor-specific antibodies bound to allograft. Upon recognizing allogeneic target cells, NK cells also secrete cytokines and chemokines that drive maturation of dendritic cells to promote cellular and humoral adaptive immune responses against the allograft. The cumulative activating and inhibitory signals generated by ligation of the receptors regulates mature NK cell killing of target cells and their production of cytokines and chemokines. This review summarizes the role of NK cells in allograft rejection and proposes mechanistic concepts that indicate a prominent role for KIR–HLA interactions in facilitating NK cells for Fc receptor-mediated ADCC effector function involved in antibody-mediated rejection of solid organ transplants. PMID:28066408

  10. The Impact of HLA Class I-Specific Killer Cell Immunoglobulin-Like Receptors on Antibody-Dependent Natural Killer Cell-Mediated Cytotoxicity and Organ Allograft Rejection.

    PubMed

    Rajalingam, Raja

    2016-01-01

    Natural killer (NK) cells of the innate immune system are cytotoxic lymphocytes that play an important roles following transplantation of solid organs and hematopoietic stem cells. Recognition of self-human leukocyte antigen (HLA) class I molecules by inhibitory killer cell immunoglobulin-like receptors (KIRs) is involved in the calibration of NK cell effector capacities during the developmental stage, allowing the subsequent recognition and elimination of target cells with decreased expression of self-HLA class I (due to virus infection or tumor transformation) or HLA class I disparities (in the setting of allogeneic transplantation). NK cells expressing an inhibitory KIR-binding self-HLA can be activated when confronted with allografts lacking a ligand for the inhibitory receptor. Following the response of the adaptive immune system, NK cells can further destroy allograft endothelium by antibody-dependent cell-mediated cytotoxicity (ADCC), triggered through cross-linking of the CD16 Fc receptor by donor-specific antibodies bound to allograft. Upon recognizing allogeneic target cells, NK cells also secrete cytokines and chemokines that drive maturation of dendritic cells to promote cellular and humoral adaptive immune responses against the allograft. The cumulative activating and inhibitory signals generated by ligation of the receptors regulates mature NK cell killing of target cells and their production of cytokines and chemokines. This review summarizes the role of NK cells in allograft rejection and proposes mechanistic concepts that indicate a prominent role for KIR-HLA interactions in facilitating NK cells for Fc receptor-mediated ADCC effector function involved in antibody-mediated rejection of solid organ transplants.

  11. T-cell mediated anti-tumor immunity after photodynamic therapy: Why does it not always work and how can we improve it?

    PubMed Central

    de Freitas, Lucas Freitas; Hamblin, Michael R

    2015-01-01

    Photodynamic therapy (PDT) uses the combination of non-toxic photosensitizers and harmless light to generate reactive oxygen species that destroy tumors by a combination of direct tumor cell killing, vascular shutdown, and activation of the immune system. It has been shown in some animal models that mice that have been cured of cancer by PDT, may exhibit resistance to rechallenge. The cured mice can also possess tumor specific T-cells that recognize defined tumor antigens, destroy tumor cells in vitro, and can be adoptively transferred to protect naïve mice from cancer. However, these beneficial outcomes are the exception rather than the rule. The reasons for this lack of consistency lie in the ability of many tumors to suppress the host immune system and to actively evade immune attack. The presence of an appropriate tumor rejection antigen in the particular tumor cell line is a requisite for T-cell mediated immunity. Regulatory T-cells (CD25+, Foxp3+) are potent inhibitors of anti-tumor immunity, and their removal by low dose cyclophosphamide can potentiate the PDT-induced immune response. Treatments that stimulate dendritic cells (DC) such as CpG oligonucleotide can overcome tumor-induced DC dysfunction and improve PDT outcome. Epigenetic reversal agents can increase tumor expression of MHC class I and also simultaneously increase expression of tumor antigens. A few clinical reports have shown that anti-tumor immunity can be generated by PDT in patients, and it is hoped that these combination approaches may increase tumor cures in patients. PMID:26062987

  12. In vivo dendrite regeneration after injury is different from dendrite development.

    PubMed

    Thompson-Peer, Katherine L; DeVault, Laura; Li, Tun; Jan, Lily Yeh; Jan, Yuh Nung

    2016-08-01

    Neurons receive information along dendrites and send signals along axons to synaptic contacts. The factors that control axon regeneration have been examined in many systems, but dendrite regeneration has been largely unexplored. Here we report that, in intact Drosophila larvae, a discrete injury that removes all dendrites induces robust dendritic growth that recreates many features of uninjured dendrites, including the number of dendrite branches that regenerate and responsiveness to sensory stimuli. However, the growth and patterning of injury-induced dendrites is significantly different from uninjured dendrites. We found that regenerated arbors cover much less territory than uninjured neurons, fail to avoid crossing over other branches from the same neuron, respond less strongly to mechanical stimuli, and are pruned precociously. Finally, silencing the electrical activity of the neurons specifically blocks injury-induced, but not developmental, dendrite growth. By elucidating the essential features of dendrites grown in response to acute injury, our work builds a framework for exploring dendrite regeneration in physiological and pathological conditions.

  13. In vivo dendrite regeneration after injury is different from dendrite development

    PubMed Central

    Li, Tun; Jan, Lily Yeh; Jan, Yuh Nung

    2016-01-01

    Neurons receive information along dendrites and send signals along axons to synaptic contacts. The factors that control axon regeneration have been examined in many systems, but dendrite regeneration has been largely unexplored. Here we report that, in intact Drosophila larvae, a discrete injury that removes all dendrites induces robust dendritic growth that recreates many features of uninjured dendrites, including the number of dendrite branches that regenerate and responsiveness to sensory stimuli. However, the growth and patterning of injury-induced dendrites is significantly different from uninjured dendrites. We found that regenerated arbors cover much less territory than uninjured neurons, fail to avoid crossing over other branches from the same neuron, respond less strongly to mechanical stimuli, and are pruned precociously. Finally, silencing the electrical activity of the neurons specifically blocks injury-induced, but not developmental, dendrite growth. By elucidating the essential features of dendrites grown in response to acute injury, our work builds a framework for exploring dendrite regeneration in physiological and pathological conditions. PMID:27542831

  14. Dendritic Growth in Undercooled Melts

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.

    1985-01-01

    The kinetic and morphological behavior of systems solidifying at small undercooling were investigated with emphasis on the role of convective and diffusive transport and the influence of gravity. A data base was established for pure succinonitrile which permits a comprehensive check on diffusional dendrite growth theory and the development of scaling laws to extend the theory to other material systems. A departure from diffusional-controlled growth was observed which becomes more significant at smaller undercoolings. A shuttle experiment is prepared to test the theory at the low undercoolings where convective effects begin to dominate.

  15. PDIA3 gene induces visceral hypersensitivity in rats with irritable bowel syndrome through the dendritic cell-mediated activation of T cells

    PubMed Central

    Zhuang, Zhaomeng; Zhang, Lu; Wang, Xiaoteng; Tao, Liyuan

    2016-01-01

    This study investigated the mechanism of protein disulfide-isomerase A3 (PDIA3)-induced visceral hypersensitivity in irritable bowel syndrome (IBS). Rats were treated with saline (control), acetic acid and restraint stress (IBS model), empty vector (RNAi control) and PDIA3-RNAi vector (PDIA3-RNAi). Mesenteric lymph node DCs (MLNDCs) and splenic CD4+/CD8+ T cells were isolated for co-cultivation. Compared with control, MLNDCs co-cultured with CD4+ or CD8+ T cells showed an increased ability to promote T cell proliferation and produced more IL-4 or IL-9 secretion. Compared with the RNAi control, MLNDCs from the PDIA3 knockdown models were less effective in promoting the proliferation of CD4+/CD8+ T cells. It is concluded that PDIA3 plays an important role in the development of IBS through the DC-mediated activation of T cells, resulting in degranulation of MCs and visceral hypersensitivity. PMID:27896022

  16. HER2-specific immunoligands engaging NKp30 or NKp80 trigger NK-cell-mediated lysis of tumor cells and enhance antibody-dependent cell-mediated cytotoxicity.

    PubMed

    Peipp, Matthias; Derer, Stefanie; Lohse, Stefan; Staudinger, Matthias; Klausz, Katja; Valerius, Thomas; Gramatzki, Martin; Kellner, Christian

    2015-10-13

    NK cells detect tumors through activating surface receptors, which bind self-antigens that are frequently expressed upon malignant transformation. To increase the recognition of tumor cells, the extracellular domains of ligands of the activating NK cell receptors NKp30, NKp80 and DNAM-1 (i.e. B7-H6, AICL and PVR, respectively) were fused to a single-chain fragment variable (scFv) targeting the human epidermal growth factor receptor 2 (HER2), which is displayed by various solid tumors. The resulting immunoligands, designated B7-H6:HER2-scFv, AICL:HER2-scFv, and PVR:HER2-scFv, respectively, bound HER2 and the addressed NK cell receptor. However, whereas B7-H6:HER2-scFv and AICL:HER2-scFv triggered NK cells to kill HER2-positive breast cancer cells at nanomolar concentrations, PVR:HER2-scFv was not efficacious. Moreover, NK cell cytotoxicity was enhanced synergistically when B7-H6:HER2-scFv or AICL:HER2-scFv were applied in combination with another HER2-specific immunoligand engaging the stimulatory receptor NKG2D. In contrast, no improvements were achieved by combining B7-H6:HER2-scFv with AICL:HER2-scFv. Additionally, B7-H6:HER2-scFv and AICL:HER2-scFv enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) by the therapeutic antibodies trastuzumab and cetuximab synergistically, with B7-H6:HER2-scFv exhibiting a higher efficacy. In summary, antibody-derived proteins engaging NKp30 or NKp80 may represent attractive biologics to further enhance anti-tumor NK cell responses and may provide an innovative approach to sensitize tumor cells for antibody-based immunotherapy.

  17. Isolation and generation of human dendritic cells.

    PubMed

    Nair, Smita; Archer, Gerald E; Tedder, Thomas F

    2012-11-01

    Dendritic cells are highly specialized antigen-presenting cells (APC), which may be isolated or generated from human blood mononuclear cells. Although mature blood dendritic cells normally represent ∼0.2% of human blood mononuclear cells, their frequency can be greatly increased using the cell enrichment methods described in this unit. More highly purified dendritic cell preparations can be obtained from these populations by sorting of fluorescence-labeled cells. Alternatively, dendritic cells can be generated from monocytes by culture with the appropriate cytokines, as described here. In addition, a negative selection approach is provided that may be employed to generate cell preparations that have been depleted of dendritic cells to be used for comparison in functional studies.

  18. Convection and diffusion effects during dendritic solidification

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Huang, S.-C.

    1979-01-01

    A report is presented of the first quantitative measurements of dendritic growth at supercooling levels where convection instead of diffusion is the controlling heat transfer mechanism. Precautions similar to that used in an investigation conducted by Glicksman et al. (1976) were taken to insure 'free' dendritic growth conditions. Dendritic growth velocity was measured as a function of growth orientation at seventeen supercoolings which ranged from 0.043 C to 2 C. Selected but representative measurements of velocity versus orientation angle are shown in a graph. The relative growth velocity of a downward growing dendrite is found to be greater than that of a diffusion-limited dendrite. This result is consistent with that expected from the enhanced heat transfer arising from natural convection.

  19. Exploiting Apoptosis for Therapeutic Tolerance Induction1

    PubMed Central

    Getts, Daniel R.; McCarthy, Derrick; Miller, Stephen D.

    2013-01-01

    Immune tolerance remains the most promising, yet elusive, strategy for treating immune-mediated diseases. An experimental strategy showing promise in phase 1 clinical studies is the delivery of antigen cross-linked to apoptotic leukocytes using ethylene carbodiimide. This approach originated from demonstration of the profound tolerance-inducing ability of intravenously administered Ag-coupled splenocytes (Ag-SP) in mice which has been demonstrated to treat T cell-mediated disorders including autoimmunity allergy and transplant rejection. Recent studies have defined the intricate interplay between the innate and adaptive immune systems in Ag-SP tolerance induction. Innate mechanisms include scavenger receptor-mediated uptake of Ag-SP by host APCs, antigen representation, and the required upregulation of PD-L1 expression and IL-10 production by splenic marginal zone macrophages leading to antigen-specific T cell regulation via the combined effects of cell-intrinsic anergy and TREG induction. Here we discuss the history, advantages, current mechanistic understanding, and clinical potential of tolerance induction using apoptotic Ag-coupled apoptotic leukocytes. PMID:24244028

  20. Candida albicans mannoprotein influences the biological function of dendritic cells.

    PubMed

    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.

  1. [The humoral and cell-mediated immune response induced by the NIVGRIP inactivated influenza vaccine].

    PubMed

    Mihail, A; Steiner, N; Berca, C; Jucu, V; Muşat, G

    1988-01-01

    A comparative study was conducted in patients vaccinated with the NIVGRIP trivalent inactivated influenza vaccine and in placebo receiving controls on the kinetics of the serum hemagglutination inhibiting (HAI) antibodies and the neutralizing secretory antibodies in the nasopharyngeal secretions (NPS), of the blastic transformation of lymphocytes index, of the rosette formation index and of the serum immunoglobulins. A significant rise of the H.A.I. and the neutralizing secretory antibodies as well as of the blastic transformation of lymphocytes index was recorded after stimulation with the influenza vaccine. There were no significant changes in controls. No significant variations of the blastic transformation of lymphocytes index after stimulation with P.P.D. and of the rosette formation index were recorded in both investigated groups. Serum immunoglobulin titres showed significant variations in vaccinated as well as in control groups. The results point out the stimulating effect of the NIVGRIP inactivated influenza vaccine on both humoral and cell mediated immune responses.

  2. Development of a simplified and convenient assay for cell-mediated immunity to the mumps virus.

    PubMed

    Otani, Naruhito; Shima, Masayuki; Nakajima, Kazuhiko; Takesue, Yoshio; Okuno, Toshiomi

    2014-09-01

    Because methods for measuring cell-mediated immunity (CMI) to the mumps virus are expensive, time-consuming, and technically demanding, the role of CMI in mumps virus infection remains unclear. To address this issue, we report here the development of a simplified method for measuring mumps virus-specific CMI that is suitable for use in diverse laboratory and clinical settings. A mumps vaccine was cultured with whole blood, and interferon (IFN)-γ released into the culture supernatant was measured using an enzyme-linked immunosorbent assay. IFN-γ production in blood from vaccinated subjects markedly increased in response to the vaccine and decreased before the antibody titer decreased in some cases, suggesting that this assay may be used as a simple surrogate method for measuring CMI specific for the mumps virus.

  3. Effect of viral and bacterial pneumonias on cell-mediated immunity in humans.

    PubMed Central

    Kauffman, C A; Linnemann, C C; Schiff, G M; Phair, J P

    1976-01-01

    Cell-mediated immunity (CMI) was assessed during infection and after convalescence in 12 patients with influenza pneumonia and 10 patients with bacterial pneumonia. The patients with influenza pneumonia had a marked impairment of skin test reactivity, and their lymphocytes showed a diminished response to phytohemagglutinin and streptokinase-streptodornase stimulation in vitro. Suppression of CMI was related to the severity of the pneumonia. Patients with bacterial pneumonia showed as great a suppression of the response to phytohemagglutinin and streptokinase-streptodornase as the patients with viral pneumonia. All parameters of CMI returned to normal in both groups after convalescence. The depression of CMI could not be related to a decrease in the number of thymus-derived lymphocytes or to serum-suppressive factors in these patients. PMID:1082445

  4. Postoperative Depression of Tumour-directed Cell-mediated Immunity in Patients with Malignant Disease

    PubMed Central

    Cochran, A. J.; Spilg, W. G. S.; Mackie, Rona M.; Thomas, Catherine E.

    1972-01-01

    Leucocytes from 46 melanoma patients, 45 breast carcinoma patients, and 95 control donors were tested by the leucocyte migration test against the supernatants of homogenates of malignant melanomas, breast carcinomas, simple breast tumours, and breasts showing simple cystic disease. By comparison with controls inhibition of migration occurred significantly more frequently when tumour patients' leucocytes were exposed to extracts of histogenetically similar tumours. Cell-mediated immunity to tumour-associated antigens was measured in 12 patients with breast carcinoma and 12 with malignant melanoma immediately before surgical operation and in the postoperative period. All patients tested before operation showed significant inhibition of migration on contact with extracts of histogenetically similar tumours. Postoperatively the degree of leucocyte migration inhibition was reduced in all patients with melanoma and breast carcinoma. Significant inhibition of leucocyte migration returned in most patients 6-22 days after operation. PMID:5077468

  5. Salmonella Modulates B Cell Biology to Evade CD8+ T Cell-Mediated Immune Responses

    PubMed Central

    Lopez-Medina, Marcela; Perez-Lopez, Araceli; Alpuche-Aranda, Celia; Ortiz-Navarrete, Vianney

    2014-01-01

    Although B cells and antibodies are the central effectors of humoral immunity, B cells can also produce and secrete cytokines and present antigen to helper T cells. The uptake of antigen is mainly mediated by endocytosis; thus, antigens are often presented by MHC-II molecules. However, it is unclear if B cells can present these same antigens via MHC-I molecules. Recently, Salmonella bacteria were found to infect B cells, allowing possible antigen cross-processing that could generate bacterial peptides for antigen presentation via MHC-I molecules. Here, we will discuss available knowledge regarding Salmonella antigen presentation by infected B cell MHC-I molecules and subsequent inhibitory effects on CD8+ T cells for bacterial evasion of cell-mediated immunity. PMID:25484884

  6. Molecular, genetic and stem cell-mediated therapeutic strategies for spinal muscular atrophy (SMA).

    PubMed

    Zanetta, Chiara; Riboldi, Giulietta; Nizzardo, Monica; Simone, Chiara; Faravelli, Irene; Bresolin, Nereo; Comi, Giacomo P; Corti, Stefania

    2014-02-01

    Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease. It is the first genetic cause of infant mortality. It is caused by mutations in the survival motor neuron 1 (SMN1) gene, leading to the reduction of SMN protein. The most striking component is the loss of alpha motor neurons in the ventral horn of the spinal cord, resulting in progressive paralysis and eventually premature death. There is no current treatment other than supportive care, although the past decade has seen a striking advancement in understanding of both SMA genetics and molecular mechanisms. A variety of disease modifying interventions are rapidly bridging the translational gap from the laboratory to clinical trials. In this review, we would like to outline the most interesting therapeutic strategies that are currently developing, which are represented by molecular, gene and stem cell-mediated approaches for the treatment of SMA.

  7. Cell-mediated fibre recruitment drives extracellular matrix mechanosensing in engineered fibrillar microenvironments

    NASA Astrophysics Data System (ADS)

    Baker, Brendon M.; Trappmann, Britta; Wang, William Y.; Sakar, Mahmut S.; Kim, Iris L.; Shenoy, Vivek B.; Burdick, Jason A.; Chen, Christopher S.

    2015-12-01

    To investigate how cells sense stiffness in settings structurally similar to native extracellular matrices, we designed a synthetic fibrous material with tunable mechanics and user-defined architecture. In contrast to flat hydrogel surfaces, these fibrous materials recapitulated cell-matrix interactions observed with collagen matrices including stellate cell morphologies, cell-mediated realignment of fibres, and bulk contraction of the material. Increasing the stiffness of flat hydrogel surfaces induced mesenchymal stem cell spreading and proliferation; however, increasing fibre stiffness instead suppressed spreading and proliferation for certain network architectures. Lower fibre stiffness permitted active cellular forces to recruit nearby fibres, dynamically increasing ligand density at the cell surface and promoting the formation of focal adhesions and related signalling. These studies demonstrate a departure from the well-described relationship between material stiffness and spreading established with hydrogel surfaces, and introduce fibre recruitment as a previously undescribed mechanism by which cells probe and respond to mechanics in fibrillar matrices.

  8. Cell-mediated fiber recruitment drives extracellular matrix mechanosensing in engineered fibrillar microenvironments

    PubMed Central

    Baker, Brendon M.; Trappmann, Britta; Wang, William Y.; Sakar, Mahmut S.; Kim, Iris L.; Shenoy, Vivek B.; Burdick, Jason A.; Chen, Christopher S.

    2015-01-01

    To investigate how cells sense stiffness in settings structurally similar to native extracellular matrices (ECM), we designed a synthetic fibrous material with tunable mechanics and user-defined architecture. In contrast to flat hydrogel surfaces, these fibrous materials recapitulated cell-matrix interactions observed with collagen matrices including stellate cell morphologies, cell-mediated realignment of fibers, and bulk contraction of the material. While increasing the stiffness of flat hydrogel surfaces induced mesenchymal stem cell spreading and proliferation, increasing fiber stiffness instead suppressed spreading and proliferation depending on network architecture. Lower fiber stiffness permitted active cellular forces to recruit nearby fibers, dynamically increasing ligand density at the cell surface and promoting the formation of focal adhesions and related signaling. These studies demonstrate a departure from the well-described relationship between material stiffness and spreading established with hydrogel surfaces, and introduce fiber recruitment as a novel mechanism by which cells probe and respond to mechanics in fibrillar matrices. PMID:26461445

  9. Optimistic Expectancies and Cell-Mediated Immunity: The Role of Positive Affect

    PubMed Central

    Segerstrom, Suzanne C.; Sephton, Sandra E.

    2014-01-01

    Optimistic expectancies affect many psychosocial outcomes and may also predict immune system changes and health, but the nature and mechanisms of any such physiological effects have not been identified. The present study related law-school expectancies to cell-mediated immunity (CMI), examining the within- and between-person components of this relationship and affective mediators. First-year law students (N = 124) completed questionnaire measures of expectancies and affect and received delayed-type hypersensitivity skin tests at five time points. A positive relationship between optimistic expectancies and CMI occurred, in which that changes in optimism correlated with changes in CMI. Likewise, changes in optimism predicted changes in positive and, to a lesser degree, negative affect, but the relationship between optimism and immunity was partially accounted for only by positive affect. This dynamic relationship between expectancies and immunity has positive implications for psychological interventions to improve health, particularly those that increase positive affect. PMID:20424083

  10. Childhood adversity and cell-mediated immunity in young adulthood: does type and timing matter?

    PubMed

    Slopen, Natalie; McLaughlin, Katie A; Dunn, Erin C; Koenen, Karestan C

    2013-02-01

    Childhood adversity can have powerful effects on health over the life course. Persistent changes in cell-mediated immune function may be one pathway linking adverse childhood experiences with later disease risk. However, limited research has examined childhood adversity in relation to cell-mediated immune function, and in particular, immune response to latent viruses in adulthood. The present study investigated the association of two types of childhood adversity, socioeconomic disadvantage during adolescence and abuse prior to age 18, with Epstein-Barr Virus (EBV) antibody titers in a large nationally representative sample of young adults aged 24-32years. Data were drawn from the National Longitudinal Study on Adolescent Health, Wave 4 (n=13,162). We examined the associations of three indicators of adolescent SES (parental education, household income, and occupational status) and frequency and timing of physical and sexual abuse with EBV antibodies, controlling for age, sex, race/ethnicity, and presence of a smoker in the household during adolescence. Lower parental occupational status and some categories of lower education were associated with elevated EBV antibodies (p<.05), and individuals who reported sexual abuse that occurred more than 10times had elevated EBV antibodies relative to individuals who were not sexually abused (p=0.03). Among individuals exposed to physical abuse, those who were first abused at age 3-5years had heightened EBV antibodies relative to those first abused during adolescence (p=0.004). This study extends prior research linking early adversity and immune function, and provides initial evidence that childhood adversity has a persistent influence on immune responses to latent infection in adulthood.

  11. Cell-Mediated Immunity to AAV Vectors, Evolving Concepts and Potential Solutions.

    PubMed

    Basner-Tschakarjan, Etiena; Mingozzi, Federico

    2014-01-01

    Adeno-associated virus (AAV) vectors are one of the most efficient in vivo gene delivery platforms. Over the past decade, clinical trials of AAV vector-mediated gene transfer led to some of the most exciting results in the field of gene therapy and, recently, to the market approval of an AAV-based drug in Europe. With clinical development, however, it became obvious that the host immune system represents an important obstacle to successful gene transfer with AAV vectors. In this review article, we will discuss the issue of cytotoxic T cell responses directed against the AAV capsid encountered on human studies. While over the past several years the field has acquired a tremendous amount of information on the interactions of AAV vectors with the immune system, a lot of questions are still unanswered. Novel concepts are emerging, such as the relationship between the total capsid dose and the T cell-mediated clearance of transduced cells, the potential role of innate immunity in vector immunogenicity highlighted in preclinical studies, and the cross talk between regulatory and effector T cells in the determination of the outcome of gene transfer. There is still a lot to learn about immune responses in AAV gene transfer, for example, it is not well understood what are the determinants of the kinetics of activation of T cells in response to vector administration, why not all subjects develop detrimental T cell responses following gene transfer, and whether the intervention strategies currently in use to block T cell-mediated clearance of transduced cells will be safe and effective for all gene therapy indications. Results from novel preclinical models and clinical studies will help to address these points and to reach the important goal of developing safe and effective gene therapy protocols to treat human diseases.

  12. STIM1 controls T cell-mediated immune regulation and inflammation in chronic infection.

    PubMed

    Desvignes, Ludovic; Weidinger, Carl; Shaw, Patrick; Vaeth, Martin; Ribierre, Theo; Liu, Menghan; Fergus, Tawania; Kozhaya, Lina; McVoy, Lauren; Unutmaz, Derya; Ernst, Joel D; Feske, Stefan

    2015-06-01

    Chronic infections induce a complex immune response that controls pathogen replication, but also causes pathology due to sustained inflammation. Ca2+ influx mediates T cell function and immunity to infection, and patients with inherited mutations in the gene encoding the Ca2+ channel ORAI1 or its activator stromal interaction molecule 1 (STIM1) are immunodeficient and prone to chronic infection by various pathogens, including Mycobacterium tuberculosis (Mtb). Here, we demonstrate that STIM1 is required for T cell-mediated immune regulation during chronic Mtb infection. Compared with WT animals, mice with T cell-specific Stim1 deletion died prematurely during the chronic phase of infection and had increased bacterial burdens and severe pulmonary inflammation, with increased myeloid and lymphoid cell infiltration. Although STIM1-deficient T cells exhibited markedly reduced IFN-γ production during the early phase of Mtb infection, bacterial growth was not immediately exacerbated. During the chronic phase, however, STIM1-deficient T cells displayed enhanced IFN-γ production in response to elevated levels of IL-12 and IL-18. The lack of STIM1 in T cells was associated with impaired activation-induced cell death upon repeated TCR engagement and pulmonary lymphocytosis and hyperinflammation in Mtb-infected mice. Chronically Mtb-infected, STIM1-deficient mice had reduced levels of inducible regulatory T cells (iTregs) due to a T cell-intrinsic requirement for STIM1 in iTreg differentiation and excessive production of IFN-γ and IL-12, which suppress iTreg differentiation and maintenance. Thus, STIM1 controls multiple aspects of T cell-mediated immune regulation to limit injurious inflammation during chronic infection.

  13. T-cell-mediated drug hypersensitivity: immune mechanisms and their clinical relevance

    PubMed Central

    Cai, Fenfen; Lee, Frederick J; Pichler, Werner J

    2016-01-01

    T-cell-mediated drug hypersensitivity represents a significant proportion of immune mediated drug hypersensitivity reactions. In the recent years, there has been an increase in understanding the immune mechanisms behind T-cell-mediated drug hypersensitivity. According to hapten mechanism, drug specific T-cell response is stimulated by drug-protein conjugate presented on major histocompatibility complex (MHC) as it is presented as a new antigenic determinant. On the other hand, p-i concept suggests that a drug can stimulate T cells via noncovalent direct interaction with T-cell receptor and/or peptide-MHC. The drug binding site is quite variable and this leads to several different mechanisms within p-i concept. Altered peptide repertoire can be regarded as an 'atypical' subset of p-i concept since the mode of the drug binding and the binding site are essentially identical to p-i concept. However, the intracellular binding of abacavir to HLA-B*57:01 additionally results in alteration in peptide repertoire. Furthermore the T-cell response to altered peptide repertoire model is only shown for abacavir and HLA-B*57:01 and therefore it may not be generalised to other drug hypersensitivity. Danger hypothesis has been postulated to play an important role in drug hypersensitivity by providing signal 2 but its experimental data is lacking at this point in time. Furthermore, the recently described allo-immune response suggests that danger signal may be unnecessary. Finally, in view of these new understanding, the classification and the definition of type B adverse drug reaction should be revised. PMID:27141480

  14. NLRP3 suppresses NK cell-mediated responses to carcinogen-induced tumors and metastases.

    PubMed

    Chow, Melvyn T; Sceneay, Jaclyn; Paget, Christophe; Wong, Christina S F; Duret, Helene; Tschopp, Jürg; Möller, Andreas; Smyth, Mark J

    2012-11-15

    The NLRP3 inflammasome acts as a danger signal sensor that triggers and coordinates the inflammatory response upon infectious insults or tissue injury and damage. However, the role of the NLRP3 inflammasome in natural killer (NK) cell-mediated control of tumor immunity is poorly understood. Here, we show in a model of chemical-induced carcinogenesis and a series of experimental and spontaneous metastases models that mice lacking NLRP3 display significantly reduced tumor burden than control wild-type (WT) mice. The suppression of spontaneous and experimental tumor metastases and methylcholanthrene (MCA)-induced sarcomas in mice deficient for NLRP3 was NK cell and IFN-γ-dependent. Focusing on the amenable B16F10 experimental lung metastases model, we determined that expression of NLRP3 in bone marrow-derived cells was necessary for optimal tumor metastasis. Tumor-driven expansion of CD11b(+)Gr-1(intermediate) (Gr-1(int)) myeloid cells within the lung tumor microenvironment of NLRP3(-/-) mice was coincident with increased lung infiltrating activated NK cells and an enhanced antimetastatic response. The CD11b(+)Gr-1(int) myeloid cells displayed a unique cell surface phenotype and were characterized by their elevated production of CCL5 and CXCL9 chemokines. Adoptive transfer of this population into WT mice enhanced NK cell numbers in, and suppression of, B16F10 lung metastases. Together, these data suggested that NLRP3 is an important suppressor of NK cell-mediated control of carcinogenesis and metastases and identify CD11b(+)Gr-1(int) myeloid cells that promote NK cell antimetastatic function.

  15. Hypoxia simultaneously alters satellite cell-mediated angiogenesis and hepatocyte growth factor expression.

    PubMed

    Flann, K L; Rathbone, C R; Cole, L C; Liu, X; Allen, R E; Rhoads, R P

    2014-05-01

    Skeletal muscle regeneration is a multifaceted process requiring the spatial and temporal coordination of myogenesis as well as angiogenesis. Hepatocyte growth factor (HGF) plays a pivotal role in myogenesis by activating satellite cells (SC) in regenerating muscle and likely plays a role as a contributor to revascularization. Moreover, repair of a functional blood supply is critical to ameliorate tissue ischemia and restore skeletal muscle function, however effects of hypoxia on satellite cell-mediated angiogenesis remain unclear. The objective of this study was to examine the role of HGF and effect of hypoxia on the capacity of satellite cells to promote angiogenesis. To characterize the role of HGF, a microvascular fragment (MVF) culture model coupled with satellite cell conditioned media (CM) was employed. The activity of HGF was specifically blocked in SC CM reducing sprout length compared to control CM. In contrast, MVF sprout number did not differ between control or HGF-deficient SC CM media. Next, we cultured MVF in the presence of CM from satellite cells exposed to normoxic (20% O2 ) or hypoxic (1% O2 ) conditions. Hypoxic CM recapitulated a MVF angiogenic response identical to HGF deficient satellite cell CM. Hypoxic conditions increased satellite cell HIF-1α protein abundance and VEGF mRNA abundance but decreased HGF mRNA abundance compared to normoxic satellite cells. Consistent with reduced HGF gene expression, HGF promoter activity decreased during hypoxia. Taken together, this data indicates that hypoxic modulation of satellite cell-mediated angiogenesis involves a reduction in satellite cell HGF expression.

  16. A novel cancer therapeutic using thrombospondin 1 in dendritic cells.

    PubMed

    Weng, Tzu-Yang; Huang, Shih-Shien; Yen, Meng-Chi; Lin, Chi-Chen; Chen, Yi-Ling; Lin, Chiu-Mei; Chen, Wei-Ching; Wang, Chih-Yang; Chang, Jang-Yang; Lai, Ming-Derg

    2014-02-01

    Induction of thrombospondin 1 (TSP-1) is generally assumed to suppress tumor growth through inhibiting angiogenesis; however, it is less clear how TSP-1 in dendritic cells (DCs) influences tumor progression. We investigated tumor growth and immune mechanism by downregulation of TSP-1 in dendritic cells. Administration of TSP-1 small hairpin RNA (shRNA) through the skin produced anticancer therapeutic effects. Tumor-infiltrating CD4(+) and CD8(+) T cells were increased after the administration of TSP-1 shRNA. The expression of interleukin-12 and interferon-γ in the lymph nodes was enhanced by injection of TSP-1 shRNA. Lymphocytes from the mice injected with TSP-1 shRNA selectively killed the tumor cells, and the cytotoxicity of lymphocytes was abolished by depletion of CD8(+) T cells. Injection of CD11c(+) TSP-1-knockout (TSP-1-KO) bone marrow-derived DCs (BMDCs) delayed tumor growth in tumor-bearing mice. Similarly, antitumor activity induced by TSP-1-KO BMDCs was abrogated by depletion of CD8(+) T cells. In contrast, the administration of shRNAs targeting TSP-2, another TSP family member, did not extend the survival of tumor-bearing mice. Finally, TSP-1 shRNA functioned as an immunotherapeutic adjuvant to augment the therapeutic efficacy of Neu DNA vaccination. Collectively, the downregulation of TSP-1 in DCs produces an effective antitumor response that is opposite to the protumor effects by silencing of TSP-1 within tumor cells.

  17. Designing vaccines based on biology of human dendritic cell subsets

    PubMed Central

    Palucka, Karolina; Banchereau, Jacques; Mellman, Ira

    2010-01-01

    The effective vaccines developed against a variety of infectious agents, including polio, measles and Hepatitis B, represent major achievements in medicine. These vaccines, usually composed of microbial antigens, are often associated with an adjuvant that activates dendritic cells (DCs). Many infectious diseases are still in need of an effective vaccine including HIV, malaria, hepatitis C and tuberculosis. In some cases, the induction of cellular rather than humoral responses may be more important as the goal is to control and eliminate the existing infection rather than to prevent it. Our increased understanding of the mechanisms of antigen presentation, particularly with the description of DC subsets with distinct functions, as well as their plasticity in responding to extrinsic signals, represent opportunities to develop novel vaccines. In addition, we foresee that this increased knowledge will permit us to design vaccines that will reprogram the immune system to intervene therapeutically in cancer, allergy and autoimmunity. PMID:21029958

  18. Antibody-mediated rejection, T cell-mediated rejection, and the injury-repair response: new insights from the Genome Canada studies of kidney transplant biopsies.

    PubMed

    Halloran, Philip F; Reeve, Jeff P; Pereira, Andre B; Hidalgo, Luis G; Famulski, Konrad S

    2014-02-01

    Prospective studies of unselected indication biopsies from kidney transplants, combining conventional assessment with molecular analysis, have created a new understanding of transplant disease states and their outcomes. A large-scale Genome Canada grant permitted us to use conventional and molecular phenotypes to create a new disease classification. T cell-mediated rejection (TCMR), characterized histologically or molecularly, has little effect on outcomes. Antibody-mediated rejection (ABMR) manifests as microcirculation lesions and transcript changes reflecting endothelial injury, interferon-γ effects, and natural killer cells. ABMR is frequently C4d negative and has been greatly underestimated by conventional criteria. Indeed, ABMR, triggered in some cases by non-adherence, is the major disease causing failure. Progressive dysfunction is usually attributable to specific diseases, and pure calcineurin inhibitor toxicity rarely explains failure. The importance of ABMR argues against immunosuppressive drug minimization and stands as a barrier to tolerance induction. Microarrays also defined the transcripts induced by acute kidney injury (AKI), which correlate with reduced function, whereas histologic changes of acute tubular injury do not. AKI transcripts are induced in kidneys with late dysfunction, and are better predictors of failure than fibrosis and inflammation. Thus progression reflects ongoing parenchymal injury, usually from identifiable diseases such as ABMR, not destructive fibrosis.

  19. Myeloid dendritic cells frequencies are increased in children with autism spectrum disorder and associated with amygdala volume and repetitive behaviors

    PubMed Central

    Breece, Elizabeth; Paciotti, Brian; Nordahl, Christine Wu; Ozonoff, Sally; Van de Water, Judy A.; Rogers, Sally J.; Amaral, David; Ashwood, Paul

    2012-01-01

    The pathophysiology of Autism Spectrum Disorder (ASD) is not yet known; however, studies suggest that dysfunction of the immune system affects many children with ASD. Increasing evidence points to dysfunction of the innate immune system including activation of microglia and perivascular macrophages, increases in inflammatory cytokines/chemokines in brain tissue and CSF, and abnormal peripheral monocyte cell function. Dendritic cells are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, antigen presentation, activation of naïve T cells, induction of tolerance and cytokine/chemokine production. In this study, we assessed circulating frequencies of myeloid dendritic cells (defined as Lin-1−BDCA1+CD11c+ and Lin-1−BDCA3+CD123−) and plasmacytoid dendritic cells (Lin-1− BDCA2+CD123+ or Lin-1−BDCA4+ CD11c−) in 57 children with ASD, and 29 typically developing controls of the same age, all of who were enrolled as part of the Autism Phenome Project (APP). The frequencies of dendritic cells and associations with behavioral assessment and MRI measurements of amygdala volume were compared in the same participants. The frequencies of myeloid dendritic cells were significantly increased in children with ASD compared to typically developing controls (p < 0.03). Elevated frequencies of myeloid dendritic cells were positively associated with abnormal right and left amygdala enlargement, severity of gastrointestinal symptoms and increased repetitive behaviors. The frequencies of plasmacytoid dendritic cells were also associated with amygdala volumes as well as developmental regression in children with ASD. Dendritic cells play key roles in modulating immune responses and differences in frequencies or functions of these cells may result in immune dysfunction in children with ASD. These data further implicate innate immune cells in the complex pathophysiology of ASD. PMID:23063420

  20. Efficient clearance of early apoptotic cells by human macrophages requires M2c polarization and MerTK induction.

    PubMed

    Zizzo, Gaetano; Hilliard, Brendan A; Monestier, Marc; Cohen, Philip L

    2012-10-01

    Mer tyrosine kinase (MerTK) is a major macrophage apoptotic cell (AC) receptor. Its functional impairment promotes autoimmunity and atherosclerosis, whereas overexpression correlates with poor prognosis in cancer. However, little is known about mechanisms regulating MerTK expression in humans. We found that MerTK expression is heterogenous among macrophage subsets, being mostly restricted to anti-inflammatory M2c (CD14(+)CD16(+)CD163(+)CD204(+)CD206(+)CD209(-)) cells, differentiated by M-CSF or glucocorticoids. Small numbers of MerTK(+) "M2c-like" cells are also detectable among circulating CD14(bright)CD16(+) monocytes. MerTK expression levels adapt to changing immunologic environment, being suppressed in M1 and M2a macrophages and in dendritic cells. Remarkably, although glucocorticoid-induced differentiation is IL-10 independent, M-CSF-driven M2c polarization and related MerTK upregulation require IL-10. However, neither IL-10 alone nor TGF-β are sufficient to fully differentiate M2c (CD16(+)CD163(+)MerTK(+)) macrophages. M-CSF and IL-10, both released by T lymphocytes, may thus be required together to promote regulatory T cell-mediated induction of anti-inflammatory monocytes-macrophages. MerTK enables M2c macrophages to clear early ACs more efficiently than other macrophage subsets, and it mediates AC clearance by CD14(bright)CD16(+) monocytes. Moreover, M2c cells release Gas6, which in turn amplifies IL-10 secretion via MerTK. IL-10-dependent induction of the Gas6/MerTK pathway may, therefore, constitute a positive loop for M2c macrophage homeostasis and a critical checkpoint for maintenance of anti-inflammatory conditions. Our findings give new insight into human macrophage polarization and favor a central role for MerTK in regulation of macrophage functions. Eliciting M2c polarization can have therapeutic utility for diseases such as lupus, in which a defective AC clearance contributes to initiate and perpetuate the pathological process.

  1. Cryptococcus gattii is killed by dendritic cells, but evades adaptive immunity by failing to induce dendritic cell maturation.

    PubMed

    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.

  2. Probe dendritic functions through poking and peeking

    NASA Astrophysics Data System (ADS)

    Xiong, Wenhui; Zhou, Zhishang; Zeng, Shaoqun; Chen, Wei R.

    2003-12-01

    Several photonic approaches have been utilized to study functional dynamics of olfactory bulb dendrites, which plays a critical role in odor discrimination and recognition. Firstly, with infrared differential interference contrast (DIC) video microscopy, we can visualize living nerve cells in an olfactory bulb slice preparation and target glass electrodes to different dendritic locations for direct electrical measurement. This furnishes a high temporal resolution of signal recording from dendrites. Secondly, by using a cooled CCD camera and loading calcium-sensitive dyes into neurons, we have explored the spatial distribution and propagation of spike signals within complex dendritic trees. Thirdly, two-photon microscope enables us to analyze active properties of very tiny dendritic structures such as dendritic spines. Lastly, by using UV light pulse to release calcium ions from caged compounds, we have examined the mechanisms for signal communication between two dendrites with reciprocal synaptic connections. Our research highlights an important contribution of optical imaging methods to functional dissection of neuronal circuitry in the brain.

  3. Dendritic potassium channels in hippocampal pyramidal neurons

    PubMed Central

    Johnston, Daniel; Hoffman, Dax A; Magee, Jeffrey C; Poolos, Nicholas P; Watanabe, Shigeo; Colbert, Costa M; Migliore, Michele

    2000-01-01

    Potassium channels located in the dendrites of hippocampal CA1 pyramidal neurons control the shape and amplitude of back-propagating action potentials, the amplitude of excitatory postsynaptic potentials and dendritic excitability. Non-uniform gradients in the distribution of potassium channels in the dendrites make the dendritic electrical properties markedly different from those found in the soma. For example, the influence of a fast, calcium-dependent potassium current on action potential repolarization is progressively reduced in the first 150 μm of the apical dendrites, so that action potentials recorded farther than 200 μm from the soma have no fast after-hyperpolarization and are wider than those in the soma. The peak amplitude of back-propagating action potentials is also progressively reduced in the dendrites because of the increasing density of a transient potassium channel with distance from the soma. The activation of this channel can be reduced by the activity of a number of protein kinases as well as by prior depolarization. The depolarization from excitatory postsynaptic potentials (EPSPs) can inactivate these A-type K+ channels and thus lead to an increase in the amplitude of dendritic action potentials, provided the EPSP and the action potentials occur within the appropriate time window. This time window could be in the order of 15 ms and may play a role in long-term potentiation induced by pairing EPSPs and back-propagating action potentials. PMID:10811726

  4. Dendritic potassium channels in hippocampal pyramidal neurons.

    PubMed

    Johnston, D; Hoffman, D A; Magee, J C; Poolos, N P; Watanabe, S; Colbert, C M; Migliore, M

    2000-05-15

    Potassium channels located in the dendrites of hippocampal CA1 pyramidal neurons control the shape and amplitude of back-propagating action potentials, the amplitude of excitatory postsynaptic potentials and dendritic excitability. Non-uniform gradients in the distribution of potassium channels in the dendrites make the dendritic electrical properties markedly different from those found in the soma. For example, the influence of a fast, calcium-dependent potassium current on action potential repolarization is progressively reduced in the first 150 micrometer of the apical dendrites, so that action potentials recorded farther than 200 micrometer from the soma have no fast after-hyperpolarization and are wider than those in the soma. The peak amplitude of back-propagating action potentials is also progressively reduced in the dendrites because of the increasing density of a transient potassium channel with distance from the soma. The activation of this channel can be reduced by the activity of a number of protein kinases as well as by prior depolarization. The depolarization from excitatory postsynaptic potentials (EPSPs) can inactivate these A-type K+ channels and thus lead to an increase in the amplitude of dendritic action potentials, provided the EPSP and the action potentials occur within the appropriate time window. This time window could be in the order of 15 ms and may play a role in long-term potentiation induced by pairing EPSPs and back-propagating action potentials.

  5. Valproic Acid Upregulates NKG2D Ligand Expression through an ERK-dependent Mechanism and Potentially Enhances NK Cell-mediated Lysis of Myeloma1

    PubMed Central

    Wu, Xiaosong; Tao, Yi; Hou, Jun; Meng, Xiuqin; Shi, Jumei

    2012-01-01

    Modulation of the antitumor immune response through the engagement of NKG2D receptors with their ligands (L) on targets represents a promising therapeutic approach against cancer. In this study, we tested the effect of valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, on the expression of NKG2D ligands in myeloma cells. We demonstrated that VPA was able to upregulate both protein and mRNA expression of major histocompatibility complex class I-related chain (MIC) A/B and UL16-binding protein (ULBP) 2 without any significant effect on the expression of ULBP1, ULBP3, and ULBP4 or induction of other natural killer (NK) cell ligands, such as NKp30-L, NKp44-L, and NKp46-L in myeloma cells. A 51Cr release assay and degranulation assay indicated that the induction of MICA/B and ULBP2 augmented NK cell-mediated lysis of myeloma cells, which was abolished by the addition of a blocking NKG2D antibody. Activation of constitutively phosphorylated extracellular signal-regulated kinase (ERK) by VPA is essential for the up-regulation of MICA/B and ULBP2 expressions. Inhibition of ERK using ERK inhibitor PD98059 decreased both MICA/B and ULBP2 expressions and NK cell cytotoxicity. Furthermore, overexpression of constitutively active ERK in ARK resulted in increased MICA/B and ULBP2 expressions and enhanced NK cell lysis. These data indicate that increased sensitivity of VPA-treated myeloma cells to NK cell lysis is caused by higher NKG2D ligand expression, resulting from more active ERK signaling pathway. Our results provide evidence that targeting ERK signaling pathway may be an additional mechanism supporting the antimyeloma activity of HDAC inhibitors and suggest its possible immunotherapeutic value for myeloma treatment. PMID:23308050

  6. Tetraspecific scFv construct provides NK cell mediated ADCC and self-sustaining stimuli via insertion of IL-15 as a cross-linker

    PubMed Central

    Schmohl, Joerg U.; Felices, Martin; Todhunter, Deborah; Taras, Elizabeth; Miller, Jeffrey S.; Vallera, Daniel A.

    2016-01-01

    Background The design of a highly effective anti-cancer immune-engager would include targeting of highly drug refractory cancer stem cells (CSC). The design would promote effective antibody-dependent cell-mediated cytotoxicity (ADCC) and simultaneously promote costimulation to expand and self-sustain the effector NK cell population. Based on our bispecific NK cell engager platform we constructed a tetraspecific killer engager (TetraKE) comprising single-chain variable fragments (scFvs) binding FcγRIII (CD16) on NK cells, EpCAM on carcinoma cells and CD133 on cancer stem cells in order to promote ADCC. Furthermore, an Interleukin (IL)-15-crosslinker enhanced NK cell related proliferation resulting in a highly active drug termed 1615EpCAM133. Results Proliferation assays showed TetraKE promoted proliferation and enhanced NK cell survival. Drug-target binding, NK cell related degranulation, and IFN-γ production was specific for both tumor related antigens in EpCAM and CD133 bearing cancer cell lines. The TetraKE showed higher killing activity and superior dose dependent degranulation. Cytokine profiling showed a moderately enhanced IFN-γ production, enhanced GM-CSF production, but no evidence of induction of excessive cytokine release. Methods Assembly and synthesis of hybrid genes encoding the TetraKE were performed using DNA shuffling and ligation. The TetraKE was tested for efficacy, specificity, proliferation, survival, and cytokine production using carcinoma cell lines and functional assays measuring NK cell activity. Conclusion 1615EpCAM133 combines improved induction of ADCC with enhanced proliferation, limited cytokine response, and prolonged survival and proliferation of NK cells. By linking scFv-related targeting of carcinoma and CSCs with a sustaining IL-15 signal, our new construct shows great promise to target cancer and CSCs. PMID:27650544

  7. Active dendrites support efficient initiation of dendritic spikes in hippocampal CA3 pyramidal neurons

    PubMed Central

    Kim, Sooyun; Guzman, Segundo J; Hu, Hua; Jonas, Peter

    2013-01-01

    CA3 pyramidal neurons are important for memory formation and pattern completion in the hippocampal network. It is generally thought that proximal synapses from the mossy fibers activate these neurons most efficiently, whereas distal inputs from the perforant path have a weaker modulatory influence. We used confocally targeted patch-clamp recording from dendrites and axons to map the activation of rat CA3 pyramidal neurons at the subcellular level. Our results reveal two distinct dendritic domains. In the proximal domain, action potentials initiated in the axon backpropagate actively with large amplitude and fast time course. In the distal domain, Na+ channel–mediated dendritic spikes are efficiently initiated by waveforms mimicking synaptic events. CA3 pyramidal neuron dendrites showed a high Na+-to-K+ conductance density ratio, providing ideal conditions for active backpropagation and dendritic spike initiation. Dendritic spikes may enhance the computational power of CA3 pyramidal neurons in the hippocampal network. PMID:22388958

  8. Fractional Cable Models for Spiny Neuronal Dendrites

    NASA Astrophysics Data System (ADS)

    Henry, B. I.; Langlands, T. A. M.; Wearne, S. L.

    2008-03-01

    Cable equations with fractional order temporal operators are introduced to model electrotonic properties of spiny neuronal dendrites. These equations are derived from Nernst-Planck equations with fractional order operators to model the anomalous subdiffusion that arises from trapping properties of dendritic spines. The fractional cable models predict that postsynaptic potentials propagating along dendrites with larger spine densities can arrive at the soma faster and be sustained at higher levels over longer times. Calibration and validation of the models should provide new insight into the functional implications of altered neuronal spine densities, a hallmark of normal aging and many neurodegenerative disorders.

  9. Solidification under microgravity conditions - Dendritic growth

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Hahn, R. C.; Lograsso, T. A.; Rubinstein, E. R.; Winsa, E.

    1987-01-01

    The experimental approach and apparatus of a zero-gravity active crystal growth experiment to test dendritic growth theory at low supercoolings are discussed. The experiment consists of 20 experimental cycles. Estimates have been made as to how low gravitational accelerations would have to be reduced to observe convection-free dendritic growth at supercoolings from 0.01-1.0 K. The experiment requires temperature control of + or - 2 mK and photographic resolution of a few microns with a depth of field of + or - 6 mm. The thermostatic bath and temperature control system, photographic system, growth chamber, and dendrite detection system are described in detail.

  10. Colostral antibody-mediated and cell-mediated immunity contributes to innate and antigen-specific immunity in piglets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoglobulins and immune cells are critical components of colostral immunity; however, their transfer to and function in the neonate, especially maternal lymphocytes, is unclear. Cell-mediated and antibody-mediated immunity in sow blood and colostrum and piglet blood before (PS) and after (AS) suc...

  11. [Exosomes derived from dendritic cells].

    PubMed

    Amigorena, S

    2001-01-01

    Dendritic cells (DC) are potent antigen presenting cells and the only ones capable of inducing primary cytotoxic immune responses both in vivo and vitro. DCs secrete a 60-80 nm membrane vesicle population of endocytic origin, called exosomes. The protein composition of exosomes was analyzed using a systematic proteomic approach. Besides MHC and costimulatory molecules, exosomes bear several adhesion proteins, probably involved in their specific targeting. Exosomes also accumulate several cytosolic factors, most likely involved in exoxome's biogenesis in late endosomes. Like DCs, exosomes induce potent anti tumor immune responses in vivo. Indeed, a single injection of DC-derived exosomes sensitized with tumor peptides induced the eradication of established mouse tumors. Tumor-specific cytotoxic T lymphocytes were found in the spleen of exosome treated mice, and depletion of CD8+ T cells in vivo inhibited the anti tumor effect of exosomes. These results strongly support the implementation of human DC-derived exosomes for cancer immunotherapy.

  12. Tumor Targeting, Trifunctional Dendritic Wedge

    PubMed Central

    2015-01-01

    We report in vitro and in vivo evaluation of a newly designed trifunctional theranostic agent for targeting solid tumors. This agent combines a dendritic wedge with high boron content for boron neutron capture therapy or boron MRI, a monomethine cyanine dye for visible-light fluorescent imaging, and an integrin ligand for efficient tumor targeting. We report photophysical properties of the new agent, its cellular uptake and in vitro targeting properties. Using live animal imaging and intravital microscopy (IVM) techniques, we observed a rapid accumulation of the agent and its retention for a prolonged period of time (up to 7 days) in fully established animal models of human melanoma and murine mammary adenocarcinoma. This macromolecular theranostic agent can be used for targeted delivery of high boron load into solid tumors for future applications in boron neutron capture therapy. PMID:25350602

  13. Dendritic Cell-Targeted Vaccines

    PubMed Central

    Cohn, Lillian; Delamarre, Lélia

    2014-01-01

    Despite significant effort, the development of effective vaccines inducing strong and durable T-cell responses against intracellular pathogens and cancer cells has remained a challenge. The initiation of effector CD8+ T-cell responses requires the presentation of peptides derived from internalized antigen on class I major histocompatibility complex molecules by dendritic cells (DCs) in a process called cross-presentation. A current strategy to enhance the effectiveness of vaccination is to deliver antigens directly to DCs. This is done via selective targeting of antigen using monoclonal antibodies directed against endocytic receptors on the surface of the DCs. In this review, we will discuss considerations relevant to the design of such vaccines: the existence of DC subsets with specialized functions, the impact of the antigen intracellular trafficking on cross-presentation, and the influence of maturation signals received by DCs on the outcome of the immune response. PMID:24910635

  14. Neurotensin promotes the dendrite elongation and the dendritic spine maturation of the cerebral cortex in vitro.

    PubMed

    Gandou, Chihiro; Ohtani, Akiko; Senzaki, Kouji; Shiga, Takashi

    2010-03-01

    We examined roles of neurotensin in the dendrite formation and the maturation of dendritic spines in the rat cerebral cortex. Embryonic day (E) 18 cortical neurons were cultured for 2 or 4 days in the presence of neurotensin. The chronic treatment of cortical neurons with neurotensin for 4 days increased the dendritic length of non-GABAergic neurons. In addition, the acute treatment of cortical neurons for 24h at 3 days in vitro also increased the dendritic length of non-GABAergic neurons similarly but more strongly than the chronic treatment. In contrast, the acute treatment for 4h had no effects on the dendrite formation. Next, we examined the effects of neurotensin on the maturation of dendritic spines. E16 cortical neurons were cultured for 10 or 14 days in a basal medium and then treated with neurotensin for 24h. At 11 days in vitro, neurotensin increased the postsynaptic density (PSD) 95-positive dendritic protrusions (filopodia, puncta and spines) together with the increase of spine density and the decrease of puncta density. At 15 days in vitro, neurotensin decreased the puncta density. In addition, the immunohistochemical localization of neurotensin type 1 and type 3 receptors in cultured neurons suggested the differential contribution of the receptors in these effects. These findings suggest that neurotensin promotes the dendrite outgrowth and the maturation of dendritic spines of cultured cortical neurons, although further studies are needed to conclude that these roles of neurotensin are also the case in vivo.

  15. Augmented IFN-γ and TNF-α Induced by Probiotic Bacteria in NK Cells Mediate Differentiation of Stem-Like Tumors Leading to Inhibition of Tumor Growth and Reduction in Inflammatory Cytokine Release; Regulation by IL-10

    PubMed Central

    Bui, Vickie T.; Tseng, Han-Ching; Kozlowska, Anna; Maung, Phyu Ou; Kaur, Kawaljit; Topchyan, Paytsar; Jewett, Anahid

    2015-01-01

    Our previous reports demonstrated that the magnitude of natural killer (NK) cell-mediated cytotoxicity correlate directly with the stage and level of differentiation of tumor cells. In addition, we have shown previously that activated NK cells inhibit growth of cancer cells through induction of differentiation, resulting in the resistance of tumor cells to NK cell-mediated cytotoxicity through secreted cytokines, as well as direct NK-tumor cell contact. In this report, we show that in comparison to IL-2 + anti-CD16mAb-treated NK cells, activation of NK cells by probiotic bacteria (sAJ2) in combination with IL-2 and anti-CD16mAb substantially decreases tumor growth and induces maturation, differentiation, and resistance of oral squamous cancer stem cells, MIA PaCa-2 stem-like/poorly differentiated pancreatic tumors, and healthy stem cells of apical papillae through increased secretion of IFN-γ and TNF-α, as well as direct NK-tumor cell contact. Tumor resistance to NK cell-mediated killing induced by IL-2 + anti-CD16mAb + sAJ2-treated NK cells is induced by combination of IFN-γ and TNF-α since antibodies to both, and not each cytokine alone, were able to restore tumor sensitivity to NK cells. Increased surface expression of CD54, B7H1, and MHC-I on NK-differentiated tumors was mediated by IFN-γ since the addition of anti-IFN-γ abolished their increase and restored the ability of NK cells to trigger cytokine and chemokine release; whereas differentiated tumors inhibited cytokine release by the NK cells. Monocytes synergize with NK cells in the presence of probiotic bacteria to induce regulated differentiation of stem cells through secretion of IL-10 resulting in resistance to NK cell-mediated cytotoxicity and inhibition of cytokine release. Therefore, probiotic bacteria condition activated NK cells to provide augmented differentiation of cancer stem cells resulting in inhibition of tumor growth, and decreased inflammatory cytokine release. PMID

  16. Distinct mechanisms of neonatal tolerance induced by dendritic cells and thymic B cells

    PubMed Central

    1991-01-01

    To assess the role of different types of antigen-presenting cells (APC) in the induction of tolerance, we isolated B cells, macrophages, and dendritic cells from thymus and spleen, and injected these into neonatal BALB/c mice across an Mls-1 antigenic barrier. One week after injection of APC from Mls-1-incompatible mice or from control syngeneic mice, we measured the number of thymic, Mls-1a-reactive, V beta 6+ T cells and the capacity of thymocytes to induce a graft-vs.-host (GVH) reaction in popliteal lymph nodes of Mls-1a mice. Injection of thymic but not spleen B cells deleted thymic, Mls-1a-reactive V beta 6+ T cells and induced tolerance in the GVH assay. The thymic B cells were primarily of the CD5+ type, and fluorescence-activated cell sorter- purified CD5+ thymic B cells were active. Injection of dendritic cells from spleen or thymus also induced tolerance, but the V beta 6 cells were anergized rather than deleted. Macrophages from thymus did not induce tolerance. Dendritic cells and thymic B cells were also effective in inducing tolerance even when injected into Mls-, major histocompatibility complex-incompatible, I-E- mice, but only thymic B cells depleted V beta 6-expressing T cells. Therefore, different types of bone marrow-derived APC have different capacities for inducing tolerance, and the active cell types (dendritic cells and CD5+ thymic B cells) can act by distinct mechanisms. PMID:1900075

  17. Using Magnetic Resonance Imaging to Evaluate Dendritic Cell-Based Vaccination

    PubMed Central

    Ferguson, Peter M.; Slocombe, Angela; Tilley, Richard D.; Hermans, Ian F.

    2013-01-01

    Cancer immunotherapy with antigen-loaded dendritic cell-based vaccines can induce clinical responses in some patients, but further optimization is required to unlock the full potential of this strategy in the clinic. Optimization is dependent on being able to monitor the cellular events that take place once the dendritic cells have been injected in vivo, and to establish whether antigen-specific immune responses to the tumour have been induced. Here we describe the use of magnetic resonance imaging (MRI) as a simple, non-invasive approach to evaluate vaccine success. By loading the dendritic cells with highly magnetic iron nanoparticles it is possible to assess whether the injected cells drain to the lymph nodes. It is also possible to establish whether an antigen-specific response is initiated by assessing migration of successive rounds of antigen-loaded dendritic cells; in the face of a successfully primed cytotoxic response, the bulk of antigen-loaded cells are eradicated on-route to the node, whereas cells without antigen can reach the node unchecked. It is also possible to verify the induction of a vaccine-induced response by simply monitoring increases in draining lymph node size as a consequence of vaccine-induced lymphocyte trapping, which is an antigen-specific response that becomes more pronounced with repeated vaccination. Overall, these MRI techniques can provide useful early feedback on vaccination strategies, and could also be used in decision making to select responders from non-responders early in therapy. PMID:23734246

  18. Multifunctional nanorods serving as nanobridges to modulate T cell-mediated immunity.

    PubMed

    Son, Young Ju; Kim, Hyesung; Leong, Kam W; Yoo, Hyuk Sang

    2013-11-26

    Electrodeposited nanorods serving as multivalent bridges were fabricated and surface-decorated with ligands for immune cells. Gold and nickel solutions were sequentially electrodeposited on nanoporous anodized disc templates and the template was dissolved to retrieve bisegmented nanorods with different lengths. Gold and nickel segmented nanorods were surface-immobilized with mannose and RGD peptides to prepare immune-cell recruiting nanorods. Surface-functionalization of nanorods were confirmed by fluorescence-labeling of each ligands and confocal microscopy. Dendritic cells and T cells were co-incubated with the surface-functionalized nanorods, and the proximity between the nanorods and the immune cells was visualized by variable pressure scanning electron microscopy and confocal microscopy. The long nanorods were associated with the immune cells, whereas the shorter nanorods were rather endocytosed by cells, suggesting a feasibility of the longer nanorods as bridging for the cells. Cytokine releases from the immune cells were monitored by cultivating lipopolysaccharide-activated dendritic cells with T cells. Interleukine-2 and interferon-γ release profiles showed a strong correlation with the length of the nanorod, where the 4 μm nanorods induced the highest levels of cytokine release compared to 1 or 2 μm nanorods. Thus, we concluded that the proximity of the immune cells increased by bridging the immune cells with the nanobridging system, which subsequently increased cytokine release by facilitating the antigen presentation process.

  19. Self-assembly of amido-ended hyperbranched polyester films with a highly ordered dendritic structure.

    PubMed

    Zhang, Daohong; Xu, Zhicai; Li, Junna; Chen, Sufang; Cheng, Juan; Zhang, Aiqing; Chen, Shenghui; Miao, Menghe

    2014-09-24

    Self-assemblies fabricated from dendrimers and amphiphilic polymers have demonstrated remarkable performances and a wide range of applications. Direct self-assembly of hyperbranched polymers into highly ordered macrostructures with heat-resistance remains a big challenge due to the weak amphiphilicity of the polymers. Here, we report the self-assembly of amphiphilic amido-ended hyperbranched polyester (HTDA-2) into millimeter-size dendritic films using combined hydrogen bond interaction and solvent induction. The self-assembly process and mechanism have been studied. Hydrogen bond interaction between amido-ended groups assists the aggregation of inner and outer chains of the HTDA-2, resulting in phase separation and micelle formation. Some micelles attach to and grow on the glass substrate like seedlings. Other micelles move to the seedlings and connect with their branches via solvent induction and hydrogen bond interaction, leading to the fabrication of highly ordered crystalline dendritic films that show high heat-resistance. HTDA-2 can further self-assemble into sheet crystals on the dendritic films.

  20. Effect of chronic microwave radiation on T cell-mediated immunity in the rabbit

    NASA Astrophysics Data System (ADS)

    Nageswari, K. Sri; Sarma, K. R.; Rajvanshi, V. S.; Sharan, R.; Sharma, Manju; Barathwal, Vinita; Singh, Vinod

    1991-06-01

    Experiments were conducted to elucidate the effects of chronic low power-level microwave radiation on the immunological systems of rabbits. Fourteen male Belgian white rabbits were exposed to microwave radiation at 5 mW/cm2, 2.1 GHz, 3 h daily, 6 days/week for 3 months in two batches of 7 each in specially designed miniature anechoicchambers. Seven rabbits were subjected to sham exposure for identical duration. The microwave energy was provided through S band standard gain horns connected to a 4K3SJ2 Klystron power amplifier. The first batch of animals were assessed for T lymphocyte-mediated cellular immune response mechanisms and the second batch of animals for B lymphocyte-mediated humoral immune response mechanisms. The peripheral blood samples collected monthly during microwave/sham exposure and during follow-up (5/14 days after termination of exposures, in the second batch animals only) were analysed for T lymphocyte numbers and their mitogen responsiveness to ConA and PHA. Significant suppression of T lymphocyte numbers was noted in the microwave group at 2 months ( P<0.01, Δ% 21.5%) and during follow-up ( P<0.01, Δ% 30.2%). The first batch animals were initially sensitised with BCG and challenged with tuberculin (0.03 ml) at the termination of microwave irradiation/sham exposure and the increase in foot pad thickness (Δ mm), which is a measure of T cell-mediated immunity (delayed type hypersensitivity response, DTH) was noted in both the groups. The microwave group revealed a better response than the control group (Δ%+12.4 vs.+7.54). The animals were sacrified and the tissue T lymphocyte counts (spleen and lymph node) were analysed. No significant variation was observed in the tissue T lymphocyte counts of microwave-irradiated rabbits. From these results it is speculated that the T lymphocytes are sequestered to various lymphoid organs under the influence of microwaves. A sub-population of T cells known as T helper cells (mediating DTH response) are

  1. Narcolepsy-Associated HLA Class I Alleles Implicate Cell-Mediated Cytotoxicity

    PubMed Central

    Tafti, Mehdi; Lammers, Gert J.; Dauvilliers, Yves; Overeem, Sebastiaan; Mayer, Geert; Nowak, Jacek; Pfister, Corinne; Dubois, Valérie; Eliaou, Jean-François; Eberhard, Hans-Peter; Liblau, Roland; Wierzbicka, Aleksandra; Geisler, Peter; Bassetti, Claudio L.; Mathis, Johannes; Lecendreux, Michel; Khatami, Ramin; Heinzer, Raphaël; Haba-Rubio, José; Feketeova, Eva; Baumann, Christian R.; Kutalik, Zoltán; Tiercy, Jean-Marie

    2016-01-01

    Study Objectives: Narcolepsy with cataplexy is tightly associated with the HLA class II allele DQB1*06:02. Evidence indicates a complex contribution of HLA class II genes to narcolepsy susceptibility with a recent independent association with HLA-DPB1. The cause of narcolepsy is supposed be an autoimmune attack against hypocretin-producing neurons. Despite the strong association with HLA class II, there is no evidence for CD4+ T-cell-mediated mechanism in narcolepsy. Since neurons express class I and not class II molecules, the final effector immune cells involved might include class I-restricted CD8+ T-cells. Methods: HLA class I (A, B, and C) and II (DQB1) genotypes were analyzed in 944 European narcolepsy with cataplexy patients and in 4,043 control subjects matched by country of origin. All patients and controls were DQB1*06:02 positive and class I associations were conditioned on DQB1 alleles. Results: HLA-A*11:01 (OR = 1.49 [1.18–1.87] P = 7.0*10−4), C*04:01 (OR = 1.34 [1.10–1.63] P = 3.23*10−3), and B*35:01 (OR = 1.46 [1.13–1.89] P = 3.64*10−3) were associated with susceptibility to narcolepsy. Analysis of polymorphic class I amino-acids revealed even stronger associations with key antigen-binding residues HLA-A-Tyr9 (OR = 1.32 [1.15–1.52] P = 6.95*10−5) and HLA-C-Ser11 (OR = 1.34 [1.15–1.57] P = 2.43*10−4). Conclusions: Our findings provide a genetic basis for increased susceptibility to infectious factors or an immune cytotoxic mechanism in narcolepsy, potentially targeting hypocretin neurons. Citation: Tafti M, Lammers GJ, Dauvilliers Y, Overeem S, Mayer G, Nowak J, Pfister C, Dubois V, Eliaou JF, Eberhard HP, Liblau R, Wierzbicka A, Geisler P, Bassetti CL, Mathis J, Lecendreux M, Khatami R, Heinzer R, Haba-Rubio J, Feketeova E, Baumann CR, Kutalik Z, Tiercy JM. Narcolepsy-associated HLA class I alleles implicate cell-mediated cytotoxicity. SLEEP 2016;39(3):581–587. PMID:26518595

  2. Dendritic spine dysgenesis in Rett syndrome

    PubMed Central

    Xu, Xin; Miller, Eric C.; Pozzo-Miller, Lucas

    2014-01-01

    Spines are small cytoplasmic extensions of dendrites that form the postsynaptic compartment of the majority of excitatory synapses in the mammalian brain. Alterations in the numerical density, size, and shape of dendritic spines have been correlated with neuronal dysfunction in several neurological and neurodevelopmental disorders associated with intellectual disability, including Rett syndrome (RTT). RTT is a progressive neurodevelopmental disorder associated with intellectual disability that is caused by loss of function mutations in the transcriptional regulator methyl CpG-binding protein 2 (MECP2). Here, we review the evidence demonstrating that principal neurons in RTT individuals and Mecp2-based experimental models exhibit alterations in the number and morphology of dendritic spines. We also discuss the exciting possibility that signaling pathways downstream of brain-derived neurotrophic factor (BDNF), which is transcriptionally regulated by MeCP2, offer promising therapeutic options for modulating dendritic spine development and plasticity in RTT and other MECP2-associated neurodevelopmental disorders. PMID:25309341

  3. Podosomes of dendritic cells facilitate antigen sampling

    PubMed Central

    Reinieren-Beeren, Inge; Cambi, Alessandra; Figdor, Carl G.; van den Bogaart, Geert

    2014-01-01

    Summary Dendritic cells sample the environment for antigens and play an important role in establishing the link between innate and acquired immunity. Dendritic cells contain mechanosensitive adhesive structures called podosomes that consist of an actin-rich core surrounded by integrins, adaptor proteins and actin network filaments. They facilitate cell migration via localized degradation of extracellular matrix. Here we show that podosomes of human dendritic cells locate to spots of low physical resistance in the substrate (soft spots) where they can evolve into protrusive structures. Pathogen recognition receptors locate to these protrusive structures where they can trigger localized antigen uptake, processing and presentation to activate T-cells. Our data demonstrate a novel role in antigen sampling for podosomes of dendritic cells. PMID:24424029

  4. Podosomes of dendritic cells facilitate antigen sampling.

    PubMed

    Baranov, Maksim V; Ter Beest, Martin; Reinieren-Beeren, Inge; Cambi, Alessandra; Figdor, Carl G; van den Bogaart, Geert

    2014-03-01

    Dendritic cells sample the environment for antigens and play an important role in establishing the link between innate and acquired immunity. Dendritic cells contain mechanosensitive adhesive structures called podosomes that consist of an actin-rich core surrounded by integrins, adaptor proteins and actin network filaments. They facilitate cell migration via localized degradation of extracellular matrix. Here, we show that podosomes of human dendritic cells locate to spots of low physical resistance in the substrate (soft spots) where they can evolve into protrusive structures. Pathogen recognition receptors locate to these protrusive structures where they can trigger localized antigen uptake, processing and presentation to activate T-cells. Our data demonstrate a novel role in antigen sampling for the podosomes of dendritic cells.

  5. Dendritic spine dysgenesis in Autism Related Disorders

    PubMed Central

    Phillips, Mary; Pozzo-Miller, Lucas

    2015-01-01

    The activity-dependent structural and functional plasticity of dendritic spines has led to the long-standing belief that these neuronal compartments are the subcellular sites of learning and memory. Of relevance to human health, central neurons in several neuropsychiatric illnesses, including autism related disorders, have atypical numbers and morphologies of dendritic spines. These so-called dendritic spine dysgeneses found in individuals with autism related disorders are consistently replicated in experimental mouse models. Dendritic spine dysgenesis reflects the underlying synaptopathology that drives clinically relevant behavioral deficits in experimental mouse models, providing a platform for testing new therapeutic approaches. By examining molecular signaling pathways, synaptic deficits, and spine dysgenesis in experimental mouse models of autism related disorders we find strong evidence for mTOR to be a critical point of convergence and promising therapeutic target. PMID:25578949

  6. HCN1 Channels Constrain Synaptically Evoked Ca2+ Spikes in Distal Dendrites of CA1 Pyramidal Neurons

    PubMed Central

    Tsay, David; Dudman, Joshua T.; Siegelbaum, Steven A.

    2008-01-01

    SUMMARY HCN1 hyperpolarization-activated cation channels act as an inhibitory constraint of both spatial learning and synaptic integration and long-term plasticity in the distal dendrites of hippocampal CA1 pyramidal neurons. However, as HCN1 channels provide an excitatory current, the mechanism of their inhibitory action remains unclear. Here we report that HCN1 channels also constrain CA1 distal dendritic Ca2+ spikes, which have been implicated in the induction of LTP at distal excitatory synapses. Our experimental and computational results indicate that HCN1 channels provide both an active shunt conductance that decreases the temporal integration of distal EPSPs and a tonic depolarizing current that increases resting inactivation of T-type and N-type voltage-gated Ca2+ channels, which contribute to the Ca2+ spikes. This dual mechanism may provide a general means by which HCN channels regulate dendritic excitability. PMID:18093528

  7. Temporal synchrony and gamma-to-theta power conversion in the dendrites of CA1 pyramidal neurons.

    PubMed

    Vaidya, Sachin P; Johnston, Daniel

    2013-12-01

    Timing is a crucial aspect of synaptic integration. For pyramidal neurons that integrate thousands of synaptic inputs spread across hundreds of microns, it is thus a challenge to maintain the timing of incoming inputs at the axo-somatic integration site. Here we show that pyramidal neurons in the rodent hippocampus use a gradient of inductance in the form of hyperpolarization-activated cation-nonselective (HCN) channels as an active mechanism to counteract location-dependent temporal differences of dendritic inputs at the soma. Using simultaneous multi-site whole-cell recordings complemented by computational modeling, we find that this intrinsic biophysical mechanism produces temporal synchrony of rhythmic inputs in the theta and gamma frequency ranges across wide regions of the dendritic tree. While gamma and theta oscillations are known to synchronize activity across space in neuronal networks, our results identify a new mechanism by which this synchrony extends to activity within single pyramidal neurons with complex dendritic arbors.

  8. Impaired Dendritic Expression and fmr1−/y Plasticity of h-Channels in the Mouse Model of Fragile X Syndrome

    PubMed Central

    Brager, Darrin H.; Akhavan, Arvin R.; Johnston, Daniel

    2012-01-01

    SUMMARY Despite extensive research into both synaptic and morphological changes, surprisingly little is known about dendritic function in fragile X syndrome (FXS). We found that the dendritic input resistance of CA1 neurons was significantly lower in fmr1−/y versus wild-type mice. Consistent with elevated dendritic Ih, voltage sag, rebound, and resonance frequency were significantly higher and temporal fmr1−/y summation was lower in the dendrites of mice. Dendritic expression of the h-channel subunit HCN1, but not HCN2, was higher in the CA1 region of fmr1−/y mice. Interestingly, whereas mGluR-mediated persistent decreases in Ih occurred in both wild-type and fmr1−/y mice, persistent increases in Ih that occurred after LTP induction in wild-type mice were absent in fmr1−/y mice. Thus, chronic upregulation of dendritic Ih in conjunction with impairment of homeostatic h-channel plasticity represents a dendritic channelopathy in this model of mental retardation and may provide a mechanism for the cognitive impairment associated with FXS. PMID:22662315

  9. Non-synaptic dendritic spines in neocortex.

    PubMed

    Arellano, J I; Espinosa, A; Fairén, A; Yuste, R; DeFelipe, J

    2007-03-16

    A long-held assumption states that each dendritic spine in the cerebral cortex forms a synapse, although this issue has not been systematically investigated. We performed complete ultrastructural reconstructions of a large (n=144) population of identified spines in adult mouse neocortex finding that only 3.6% of the spines clearly lacked synapses. Nonsynaptic spines were small and had no clear head, resembling dendritic filopodia, and could represent a source of new synaptic connections in the adult cerebral cortex.

  10. Dendritic signals from rat hippocampal CA1 pyramidal neurons during coincident pre- and post-synaptic activity: a combined voltage- and calcium-imaging study

    PubMed Central

    Canepari, Marco; Djurisic, Maja; Zecevic, Dejan

    2007-01-01

    The non-linear and spatially inhomogeneous interactions of dendritic membrane potential signals that represent the first step in the induction of activity-dependent long-term synaptic plasticity are not fully understood, particularly in dendritic regions which are beyond the reach of electrode measurements. We combined voltage-sensitive-dye recordings and Ca2+ imaging of hippocampal CA1 pyramidal neurons to study large regions of the dendritic arbor, including branches of small diameter (distal apical and oblique dendrites). Dendritic membrane potential transients were monitored at high spatial resolution and correlated with supra-linear [Ca2+]i changes during one cycle of a repetitive patterned stimulation protocol that typically results in the induction of long-term potentiation (LTP). While the increase in the peak membrane depolarization during coincident pre- and post-synaptic activity was required for the induction of supra-linear [Ca2+]i signals shown to be necessary for LTP, the change in the baseline-to-peak amplitude of the backpropagating dendritic action potential (bAP) was not critical in this process. At different dendritic locations, the baseline-to-peak amplitude of the bAP could be either increased, decreased or unaltered at sites where EPSP–AP pairing evoked supra-linear summation of [Ca2+]i transients. We suggest that modulations in the bAP baseline-to-peak amplitude by local EPSPs act as a mechanism that brings the membrane potential into the optimal range for Ca2+ influx through NMDA receptors (0 to −15 mV); this may require either boosting or the reduction of the bAP, depending on the initial size of both signals. PMID:17272348

  11. Transcranial magnetic stimulation (TMS) inhibits cortical dendrites

    PubMed Central

    Murphy, Sean C; Palmer, Lucy M; Nyffeler, Thomas; Müri, René M; Larkum, Matthew E

    2016-01-01

    One of the leading approaches to non-invasively treat a variety of brain disorders is transcranial magnetic stimulation (TMS). However, despite its clinical prevalence, very little is known about the action of TMS at the cellular level let alone what effect it might have at the subcellular level (e.g. dendrites). Here, we examine the effect of single-pulse TMS on dendritic activity in layer 5 pyramidal neurons of the somatosensory cortex using an optical fiber imaging approach. We find that TMS causes GABAB-mediated inhibition of sensory-evoked dendritic Ca2+ activity. We conclude that TMS directly activates fibers within the upper cortical layers that leads to the activation of dendrite-targeting inhibitory neurons which in turn suppress dendritic Ca2+ activity. This result implies a specificity of TMS at the dendritic level that could in principle be exploited for investigating these structures non-invasively. DOI: http://dx.doi.org/10.7554/eLife.13598.001 PMID:26988796

  12. Synaptic Control of Secretory Trafficking in Dendrites

    PubMed Central

    Hanus, Cyril; Kochen, Lisa; Dieck, Susanne tom; Racine, Victor; Sibarita, Jean-Baptiste; Schuman, Erin M.; Ehlers, Michael D.

    2016-01-01

    Summary Localized signaling in neuronal dendrites requires tight spatial control of membrane composition. Upon initial synthesis, nascent secretory cargo in dendrites exits the endoplasmic reticulum (ER) from local zones of ER complexity that are spatially coupled to post-ER compartments. Although newly synthesized membrane proteins can be processed locally, the mechanisms that control the spatial range of secretory cargo transport in dendritic segments are unknown. Here, we monitored the dynamics of nascent membrane proteins in dendritic post-ER compartments under regimes of low or increased neuronal activity. In response to activity blockade, post-ER carriers are highly mobile and are transported over long distances. Conversely, increasing synaptic activity dramatically restricts the spatial scale of post-ER trafficking along dendrites. This activity-induced confinement of secretory cargo requires site-specific phosphorylation of the kinesin motor KIF17 by Ca2+/calmodulin-dependent protein kinases (CaMK). Thus, the length scales of early secretory trafficking in dendrites are tuned by activity-dependent regulation of microtubule-dependent transport. PMID:24931613

  13. Fast Kalman filtering on quasilinear dendritic trees.

    PubMed

    Paninski, Liam

    2010-04-01

    Optimal filtering of noisy voltage signals on dendritic trees is a key problem in computational cellular neuroscience. However, the state variable in this problem-the vector of voltages at every compartment-is very high-dimensional: realistic multicompartmental models often have on the order of N = 10(4) compartments. Standard implementations of the Kalman filter require O(N (3)) time and O(N (2)) space, and are therefore impractical. Here we take advantage of three special features of the dendritic filtering problem to construct an efficient filter: (1) dendritic dynamics are governed by a cable equation on a tree, which may be solved using sparse matrix methods in O(N) time; and current methods for observing dendritic voltage (2) provide low SNR observations and (3) only image a relatively small number of compartments at a time. The idea is to approximate the Kalman equations in terms of a low-rank perturbation of the steady-state (zero-SNR) solution, which may be obtained in O(N) time using methods that exploit the sparse tree structure of dendritic dynamics. The resulting methods give a very good approximation to the exact Kalman solution, but only require O(N) time and space. We illustrate the method with applications to real and simulated dendritic branching structures, and describe how to extend the techniques to incorporate spatially subsampled, temporally filtered, and nonlinearly transformed observations.

  14. Paper-based bioactive scaffolds for stem cell-mediated bone tissue engineering.

    PubMed

    Park, Hyun-Ji; Yu, Seung Jung; Yang, Kisuk; Jin, Yoonhee; Cho, Ann-Na; Kim, Jin; Lee, Bora; Yang, Hee Seok; Im, Sung Gap; Cho, Seung-Woo

    2014-12-01

    Bioactive, functional scaffolds are required to improve the regenerative potential of stem cells for tissue reconstruction and functional recovery of damaged tissues. Here, we report a paper-based bioactive scaffold platform for stem cell culture and transplantation for bone reconstruction. The paper scaffolds are surface-engineered by an initiated chemical vapor deposition process for serial coating of a water-repellent and cell-adhesive polymer film, which ensures the long-term stability in cell culture medium and induces efficient cell attachment. The prepared paper scaffolds are compatible with general stem cell culture and manipulation techniques. An optimal paper type is found to provide structural, physical, and mechanical cues to enhance the osteogenic differentiation of human adipose-derived stem cells (hADSCs). A bioactive paper scaffold significantly enhances in vivo bone regeneration of hADSCs in a critical-sized calvarial bone defect. Stacking the paper scaffolds with osteogenically differentiated hADSCs and human endothelial cells resulted in vascularized bone formation in vivo. Our study suggests that paper possesses great potential as a bioactive, functional, and cost-effective scaffold platform for stem cell-mediated bone tissue engineering. To the best of our knowledge, this is the first study reporting the feasibility of a paper material for stem cell application to repair tissue defects.

  15. Crosstalk between PKCζ and the IL4/Stat6 pathway during T-cell-mediated hepatitis

    PubMed Central

    Durán, Angeles; Rodriguez, Angelina; Martin, Pilar; Serrano, Manuel; Flores, Juana Maria; Leitges, Michael; Diaz-Meco, María T; Moscat, Jorge

    2004-01-01

    PKCζ is required for nuclear factor κ-B (NF-κB) activation in several cell systems. NF-κB is a suppressor of liver apoptosis during development and in concanavalin A (ConA)-induced T-cell-mediated hepatitis. Here we show that PKCζ−/− mice display inhibited ConA-induced NF-κB activation and reduced damage in liver. As the IL-4/Stat6 pathway is necessary for ConA-induced hepatitis, we addressed here the potential role of PKCζ in this cascade. Interestingly, the loss of PKCζ severely attenuated serum IL-5 and liver eotaxin-1 levels, two critical mediators of liver damage. Stat6 tyrosine phosphorylation and Jak1 activation were ablated in the liver of ConA-injected PKCζ−/− mice and in IL-4-stimulated PKCζ−/− fibroblasts. PKCζ interacts with and phosphorylates Jak1 and PKCζ activity is required for Jak1 function. In contrast, Par-4−/− mice have increased sensitivity to ConA-induced liver damage and IL-4 signaling. This unveils a novel and critical involvement of PKCζ in the IL-4/Stat6 signaling pathway in vitro and in vivo. PMID:15526032

  16. Growth suppression of Leydig TM3 cells mediated by aryl hydrocarbon receptor

    SciTech Connect

    Iseki, Minoru; Ikuta, Togo; Kobayashi, Tetsuya; Kawajiri, Kaname . E-mail: kawajiri@cancer-c.pref.saitama.jp

    2005-06-17

    Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental toxicity in reproductive organs. To elucidate the function of AhR, we generated stable transformants of TM3 cells overexpressing wild-type aryl hydrocarbon receptor (AhR) or its mutants which carried mutations in nuclear localization signal or nuclear export signal. In the presence of 3-methylcholanthrene (MC), proliferation of the cells transfected with wild-type AhR was completely suppressed, whereas cells expressing AhR mutants proliferated in a manner equivalent to control TM3 cells, suggesting AhR-dependent growth inhibition. The suppression was associated with up-regulation of cyclin-dependent kinase inhibitor p21{sup Cip1}, which was abolished by pretreatment with actinomycin D. A p38 MAPK specific inhibitor, SB203580, blocked the increase of p21{sup Cip1} mRNA in response to MC. Treatment with indigo, another AhR ligand, failed to increase of p21{sup Cip1} mRNA, although up-regulation of mRNA for CYP1A1 was observed. These data suggest AhR in Leydig cells mediates growth inhibition by inducing p21{sup Cip1}.

  17. Hepatic non-parenchymal cells and extracellular matrix participate in oval cell-mediated liver regeneration

    PubMed Central

    Zhang, Wei; Chen, Xiao-Ping; Zhang, Wan-Guang; Zhang, Feng; Xiang, Shuai; Dong, Han-Hua; Zhang, Lei

    2009-01-01

    AIM: To elucidate the interaction between non-parenchymal cells, extracellular matrix and oval cells during the restituting process of liver injury induced by partial hepatectomy (PH). METHODS: We examined the localization of oval cells, non-parenchymal cells, and the extracellular matrix components using immunohistochemical and double immunofluorescent analysis during the proliferation and differentiation of oval cells in N-2-acetylaminofluorene (2-AAF)/PH rat model. RESULTS: By day 2 after PH, small oval cells began to proliferate around the portal area. Most of stellate cells and laminin were present along the hepatic sinusoids in the periportal area. Kupffer cells and fibronectin markedly increased in the whole hepatic lobule. From day 4 to 9, oval cells spread further into hepatic parenchyma, closely associated with stellate cells, fibronectin and laminin. Kupffer cells admixed with oval cells by day 6 and then decreased in the periportal zone. From day 12 to 15, most of hepatic stellate cells (HSCs), laminin and fibronectin located around the small hepatocyte nodus, and minority of them appeared in the nodus. Kupffer cells were mainly limited in the pericentral sinusoids. After day 18, the normal liver lobule structures began to recover. CONCLUSION: Local hepatic microenvironment may participate in the oval cell-mediated liver regeneration through the cell-cell and cell-matrix interactions. PMID:19195056

  18. New gene expressed in prostate: a potential target for T cell-mediated prostate cancer immunotherapy.

    PubMed

    Cereda, Vittore; Poole, Diane J; Palena, Claudia; Das, Sudipto; Bera, Tapan K; Remondo, Cinzia; Gulley, James L; Arlen, Philip M; Yokokawa, Junko; Pastan, Ira; Schlom, Jeffrey; Tsang, Kwong Y

    2010-01-01

    New gene expressed in prostate (NGEP) is a prostate-specific gene encoding either a small cytoplasmic protein (NGEP-S) or a larger polytopic membrane protein (NGEP-L). NGEP-L expression is detectable only in prostate cancer, benign prostatic hyperplasia and normal prostate. We have identified an HLA-A2 binding NGEP epitope (designated P703) which was used to generate T cell lines from several patients with localized and metastatic prostate cancer. These T cell lines were able to specifically lyse HLA-A2 and NGEP-expressing human tumor cells. NGEP-P703 tetramer binding assays demonstrated that metastatic prostate cancer patients had a higher frequency of NGEP-specific T cells when compared with healthy donors. Moreover, an increased frequency of NGEP-specific T cells was detected in the peripheral blood mononuclear cells of prostate cancer patients post-vaccination with a PSA-based vaccine, further indicating the immunogenicity of NGEP. These studies thus identify NGEP as a potential target for T cell-mediated immunotherapy of prostate cancer.

  19. TRESK channel as a potential target to treat T-cell mediated immune dysfunction

    SciTech Connect

    Han, Jaehee; Kang, Dawon

    2009-12-25

    In this review, we propose that TRESK background K{sup +} channel could serve as a potential therapeutic target for T-cell mediated immune dysfunction. TRESK has many immune function-related properties. TRESK is abundantly expressed in the thymus, the spleen, and human leukemic T-lymphocytes. TRESK is highly activated by Ca{sup 2+}, calcineurin, acetylcholine, and histamine which induce hypertrophy, whereas TRESK is inhibited by immunosuppressants, such as cyclosporin A and FK506. Cyclosporine A and FK506 target the binding site of nuclear factor of activated T-cells (NFAT) to inhibit calcineurin. Interestingly, TRESK possesses an NFAT-like docking site that is present at its intracellular loop. Calcineurin has been found to interact with TRESK via specific NFAT-like docking site. When the T-cell is activated, calcineurin can bind to the NFAT-docking site of TRESK. The activation of both TRESK and NFAT via Ca{sup 2+}-calcineurin-NFAT/TRESK pathway could modulate the transcription of new genes in addition to regulating several aspects of T-cell function.

  20. Epstein-Barr Virus Reactivation Associated with Diminished Cell-Mediated Immunity in Antarctic Expeditioners

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Mehta, Satish K.; Cooley, Helen; Dubow, Robin; Lugg, Desmond

    1999-01-01

    Reactivation of Epstein-Barr virus (EBV) and cell-mediated immune (CMI) responses were followed in 16 Antarctic expeditioners during winter-over isolation at two Australian National Antarctic Research Expedition stations. Delayed-type hypersensitivity skin testing was used as an indicator of the CMI response, which was evaluated two times before winter isolation and three times during isolation. At all five evaluation times, 8 or more of the 16 subjects had a diminished. CMI response. Diminished CMI was observed on every test occasion in 4/16 subjects; only 2/16 subjects exhibited normal CMI responses for all five tests. A polymerase chain reaction (PCR) assay was used to detect EBV DNA in saliva specimens collected before, after, and during the winter isolation. EBV DNA was present in 17% (111/642) of the saliva specimens; all 16 subjects shed EBV in their saliva on at least one occasion. The probability of EBV shedding increased (p=0.013) from 6% before or after winter isolation to 13% during the winter period. EBV appeared in saliva during the winter isolation more frequently (p<0.0005) when CMI responsiveness was diminished than when CMI status was normal. The findings indicate that the psychosocial, physical, and other stresses associated with working and living in physical isolation during the Antarctic winter results in diminished CMI and an accompanying increased reactivation and shedding of latent viruses.

  1. Inhibitory effect of Moutan Cortex aqueous fraction on mast cell-mediated allergic inflammation.

    PubMed

    Kee, Ji-Ye; Inujima, Akiko; Andoh, Tsugunobu; Tanaka, Ken; Li, Feng; Kuraishi, Yasushi; Sakurai, Hiroaki; Shibahara, Naotoshi; Saiki, Ikuo; Koizumi, Keiichi

    2015-04-01

    Moutan Cortex and its major compounds have been shown to possess various biological activities, including anti-inflammatory properties. However, the effects of Moutan Cortex aqueous fraction (MCA) and its molecular mechanisms have yet to be elucidated. In this study, we attempted to evaluate the effects of MCA on mast cell-mediated allergy inflammation in vitro and in vivo compared with major Moutan Cortex compounds. Thus, we examined the anti-inflammatory effects of a water extract of Moutan Cortex by comparing the inhibition of β-hexosaminadase and tumor necrosis factor-α (TNF-α) release in an aqueous fraction with other major compounds of Moutan Cortex. The inhibitory mechanism of MCA was investigated by western blotting in IgE-mediated DNP-BSA-stimulated RBL-2H3 cells. We confirmed the pharmacological effects of MCA on compound 48/80-induced allergic reactions in a mouse model by assessing scratching behavior and passive cutaneous anaphylaxis (PCA)-like reaction. Consequently, MCA inhibited IgE-mediated DNP-BSA-induced β-hexosaminadase and TNF-α release via inactivation of p38, ERK, Akt, and NF-κB in RBL-2H3 cells. MCA reduced compound 48/80-induced PCA reaction and scratching behavior in mice. This inhibitory effect of MCA is more potent than major compounds of Moutan Cortex. In conclusion, our results suggest that MCA has more potential in the treatment of allergic inflammatory diseases compared to other major compounds of Moutan Cortex.

  2. Cell mediated immune response of the Mediterranean sea urchin Paracentrotus lividus after PAMPs stimulation.

    PubMed

    Romero, A; Novoa, B; Figueras, A

    2016-09-01

    The Mediterranean sea urchin (Paracentrotus lividus) is of great ecological and economic importance for the European aquaculture. Yet, most of the studies regarding echinoderm's immunological defense mechanisms reported so far have used the sea urchin Strongylocentrotus purpuratus as a model, and information on the immunological defense mechanisms of Paracentrotus lividus and other sea urchins, is scarce. To remedy this gap in information, in this study, flow cytometry was used to evaluate several cellular immune mechanisms, such as phagocytosis, cell cooperation, and ROS production in P. lividus coelomocytes after PAMP stimulation. Two cell populations were described. Of the two, the amoeboid-phagocytes were responsible for the phagocytosis and ROS production. Cooperation between amoeboid-phagocytes and non-adherent cells resulted in an increased phagocytic response. Stimulation with several PAMPs modified the phagocytic activity and the production of ROS. The premise that the coelomocytes were activated by the bacterial components was confirmed by the expression levels of two cell mediated immune genes: LPS-Induced TNF-alpha Factor (LITAF) and macrophage migration inhibitory factor (MIF). These results have helped us understand the cellular immune mechanisms in P. lividus and their modulation after PAMP stimulation.

  3. Xanthohumol attenuates tumour cell-mediated breaching of the lymphendothelial barrier and prevents intravasation and metastasis.

    PubMed

    Viola, Katharina; Kopf, Sabine; Rarova, Lucie; Jarukamjorn, Kanokwan; Kretschy, Nicole; Teichmann, Mathias; Vonach, Caroline; Atanasov, Atanas G; Giessrigl, Benedikt; Huttary, Nicole; Raab, Ingrid; Krieger, Sigurd; Strnad, Miroslav; de Martin, Rainer; Saiko, Philipp; Szekeres, Thomas; Knasmüller, Siegfried; Dirsch, Verena M; Jäger, Walter; Grusch, Michael; Dolznig, Helmut; Mikulits, Wolfgang; Krupitza, Georg

    2013-07-01

    Health beneficial effects of xanthohumol have been reported, and basic research provided evidence for anti-cancer effects. Furthermore, xanthohumol was shown to inhibit the migration of endothelial cells. Therefore, this study investigated the anti-metastatic potential of xanthohumol. MCF-7 breast cancer spheroids which are placed on lymphendothelial cells (LECs) induce "circular chemorepellent-induced defects" (CCIDs) in the LEC monolayer resembling gates for intravasating tumour bulks at an early step of lymph node colonisation. NF-κB reporter-, EROD-, SELE-, 12(S)-HETE- and adhesion assays were performed to investigate the anti-metastatic properties of xanthohumol. Western blot analyses were used to elucidate the mechanisms inhibiting CCID formation. Xanthohumol inhibited the activity of CYP, SELE and NF-kB and consequently, the formation of CCIDs at low micromolar concentrations. More specifically, xanthohumol affected ICAM-1 expression and adherence of MCF-7 cells to LECs, which is a prerequisite for CCID formation. Furthermore, markers of epithelial-to-mesenchymal transition (EMT) and of cell mobility such as paxillin, MCL2 and S100A4 were suppressed by xanthohumol. Xanthohumol attenuated tumour cell-mediated defects at the lymphendothelial barrier and inhibited EMT-like effects thereby providing a mechanistic explanation for the anti-intravasative/anti-metastatic properties of xanthohumol.

  4. Periodontal Ligament Stem Cell-Mediated Treatment for Periodontitis in Miniature Swine

    PubMed Central

    Liu, Yi; Zheng, Ying; Ding, Gang; Fang, Dianji; Zhang, Chunmei; Bartold, Peter Mark; Gronthos, Stan; Shi, Songtao; Wang, Songlin

    2009-01-01

    Periodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases. PMID:18238856

  5. Changes in cell-mediated immune response after lung resection surgery for MDR-TB patients.

    PubMed

    Park, Seung-Kyu; Hong, Sunghee; Eum, Seok-Yong; Lee, In Hee; Shin, Donk Ok; Cho, Jang Eun; Cho, Sungae; Cho, Sang-Nae

    2011-07-01

    The immune responses of multidrug-resistant tuberculosis (MDR-TB) patients undergoing lung resection surgery were investigated in order to understand the mechanism of strong immune suppression in MDR-TB. We examined changes in cell-mediated immune response (CMI) of a total of sixteen MDR-TB patients, three of them extensively drug-resistant tuberculosis (XDR-TB) patients, after the removal of the heavily diseased lung section. The IFN-γ response to Mycobacterium tuberculosis culture filtrate proteins (Mtb-CFP), one of the most important CMI to defend TB, showed a statistically significant elevation in 2-4 months after operation when compared to the preoperative CMI in patients who were converted into AFB negative and cured in two years' follow-up, suggesting that the recovery of CMI may be one of the key factors in the successful treatment of MDR-TB. Interestingly, IL-10 response to Mtb-CFP was also elevated in 2-4 months after surgery in cured patients although both proliferative response and PBMC composition were not significantly changed. Infection with first- or second-line drugs resistant Mtb reduces the efficiency of chemotherapeutic treatment of MDR-TB to about 50%. Thus, this study suggests that chemotherapeutic treatment of MDR-TB may be more effective when combined with accompanying therapy that increases CMI, includes lung resection surgery.

  6. Laminin: a possible role as a mediator of natural cell-mediated functions

    SciTech Connect

    Laybourn, K.A.

    1986-01-01

    Natural Cell-mediated cytotoxicity is clearly important in regulating host response during tumorgenicity. Natural killer (NK), and Natural Cytotoxic (NC) lymphocytes responsible for mediating cytolysis, are subpopulations of non-B, non-T, nonphagocytic, nonadherent lymphocytes capable of spontaneously lysing a variety of tumor targets. Evidence is presented that laminin, a high molecular weight glycoprotein, is present on the surface of murine NK cells. In addition, NK sensitive tumor targets are able to bind laminin. This suggest that laminin participates as a ligand in the binding of NK cells to their tumor targets. The saturable binding of laminin by NK and NC sensitive tumor targets was shown by laminin-induced cell-cell aggregation/adherence, and /sup 125/I-laminin binding studies. Exogenous laminin inhibited NK cytotoxicity but not CTL cytotoxicity in vitro. In comparison, NK-resistant tumor cells bound little, if any exogenous laminin. Modulating NK activity in vivo prior to challenging mice with an inoculation of a murine fibrosarcoma, showed that elimination or activation of NK activity resulted in an increase or decrease in pulmonary metastases, respectively.

  7. Signaling factors in stem cell-mediated repair of infarcted myocardium.

    PubMed

    Vandervelde, S; van Luyn, M J A; Tio, R A; Harmsen, M C

    2005-08-01

    Myocardial infarction leads to scar formation and subsequent reduced cardiac performance. The ultimate therapy after myocardial infarction would pursue stem cell-based regeneration. The aim of stem cell-mediated cardiac repair embodies restoration of cardiac function by regeneration of healthy myocardial tissue, which is accomplished by neo-angiogenesis and cardiogenesis. A major reservoir of adult autologous stem cells distal from the heart is the bone marrow. Adequate regulation of signaling between the bone marrow, the peripheral circulation and the infarcted myocardium is important in orchestrating the process of mobilization, homing, incorporation, survival, proliferation and differentiation of stem cells, that leads to myocardial regeneration. In this review, we discuss key signaling factors, including cytokines, chemokines and growth factors, which are involved in orchestrating the stem cell driven repair process. We focus on signaling factors known for their mobilizing and chemotactic abilities (SDF-1, G-CSF, SCF, IL-8, VEGF), signaling factors that are expressed after myocardial infarction involved in the patho-physiological healing process (TNF-alpha, IL-8, IL-10, HIF-1alpha, VEGF, G-CSF) and signaling factors that are involved in cardiogenesis and neo-angiogenesis (VEGF, EPO, TGF-beta, HGF, HIF-1alpha, IL-8). The future therapeutic application and capacity of secreted factors to modulate tissue repair after myocardial infarction relies on the intrinsic potency of factors and on the optimal localization and timing of a combination of signaling factors to stimulate stem cells in their niche to regenerate the infarcted heart.

  8. Human mast cell mediator cocktail excites neurons in human and guinea-pig enteric nervous system.

    PubMed

    Schemann, M; Michel, K; Ceregrzyn, M; Zeller, F; Seidl, S; Bischoff, S C

    2005-04-01

    Neuroimmune interactions are an integral part of gut physiology and involved in the pathogenesis of inflammatory and functional bowel disorders. Mast cells and their mediators are important conveyors in the communication from the innate enteric immune system to the enteric nervous system (ENS). However, it is not known whether a mediator cocktail released from activated human mast cells affects neural activity in the ENS. We used the Multi-Site Optical Recording Technique to image single cell activity in guinea-pig and human ENS after application of a mast cell mediator cocktail (MCMC) that was released from isolated human intestinal mucosa mast cells stimulated by IgE-receptor cross-linking. Local application of MCMC onto individual ganglia evoked an excitatory response consisting of action potential discharge. This excitatory response occurred in 31%, 38% or 11% neurons of guinea-pig submucous plexus, human submucous plexus, or guinea-pig myenteric plexus, respectively. Compound action potentials from nerve fibres or fast excitatory synaptic inputs were not affected by MCMC. This study demonstrates immunoneural signalling in the human gut and revealed for the first time that an MCMC released from stimulated human intestinal mast cells induces excitatory actions in the human and guinea-pig ENS.

  9. Effects of endosulfan on humoral and cell-mediated immune responses in rats

    SciTech Connect

    Banerjee, B.D.; Hussain, Q.Z.

    1987-03-01

    Endosulfan (6,7,8,9,10,10a-hexa-chloro-1,5,5a,6,9,9a-hexahydro, 6,9-methano-2,4,3-benzodioxathiepin-3-oxide), a polycyclic chlorinated hydrocarbon of cyclodien group, is a well known insecticide. Food is the main source of exposure of the general population to endosulfan. The physical, chemical as well as toxicological effects of endosulfan in experimental animals have been reported by various workers. However, the reports regarding the effect of endosulfan on immune system are not available. In view of its widespread use there is an urgent need to investigate the immunotoxicological effect of endosulfan in mammals for the safety evaluation of this insecticide. This has, therefore, prompted the authors to investigate the effect of endosulfan on immune system employing albino rats as the experimental animals. Included in this report are their preliminary findings on humoral and cell-mediated immune responses in rats exposed to sub-chronic doses of endosulfan.

  10. Epstein-Barr virus reactivation associated with diminished cell-mediated immunity in antarctic expeditioners

    NASA Technical Reports Server (NTRS)

    Mehta, S. K.; Pierson, D. L.; Cooley, H.; Dubow, R.; Lugg, D.

    2000-01-01

    Epstein-Barr virus (EBV) reactivation and cell-mediated immune (CMI) responses were followed in 16 Antarctic expeditioners during winter-over isolation at 2 Australian National Antarctic Research Expedition stations. Delayed-type hypersensitivity (DTH) skin testing was used as an indicator of the CMI response, that was evaluated 2 times before winter isolation and 3 times during isolation. At all 5 evaluation times, 8 or more of the 16 subjects had a diminished CMI response. Diminished DTH was observed on every test occasion in 4/16 subjects; only 2/16 subjects exhibited normal DTH responses for all 5 tests. A polymerase chain reaction (PCR) assay was used to detect EBV DNA in saliva specimens collected before, during, and after the winter isolation. EBV DNA was present in 17% (111/642) of the saliva specimens; all 16 subjects shed EBV in their saliva on at least 1 occasion. The probability of EBV shedding increased (P = 0.013) from 6% before or after winter isolation to 13% during the winter period. EBV appeared in saliva during the winter isolation more frequently (P < 0.0005) when DTH response was diminished than when DTH was normal. The findings indicate that the psychosocial, physical, and other stresses associated with working and living in physical isolation during the Antarctic winter result in diminished CMI and an accompanying increased reactivation and shedding of latent viruses.

  11. Triphasic mixture model of cell-mediated enzymatic degradation of hydrogels

    PubMed Central

    Vernerey, Franck J.; Greenwald, Eric C.; Bryant, Stephanie J.

    2012-01-01

    In order to engineer living tissue equivalents, a critical component is designing scaffolds, such as hydrogels, whose degradation kinetics can match that of matrix production by cells. However, cell-mediated enzymatic degradation of a hydrogel is highly complex and nonlinear process that is challenging to comprehend based solely on experimental observations. To address this issue, this study presents a triphasic mixture model of the enzyme/hydrogel system, that consists of a solid polymer network, water and enzyme. Based on mixture theory, rubber elasticity theory and the Michaelis-Menton kinetics for degradation, the model naturally incorporates a strong coupling between gel mechanical properties, the kinetics of degradation and the transport of enzyme through the gel. The model is then used to investigate the particular problem of a single spherical enzyme-producing cell, embedded in a spherical hydrogel domain, for which the governing equations can be cast within the cento-symmetric assumptions. The governing equations are subsequently solved using an implicit nonlinear finite element procedure in order to obtain the evolution of enzyme concentration and gel degradation through time and space. The model shows that two regimes of degradation behavior exist, whereby degradation is dominated either by diffusion or dominated by reaction kinetics. Depending on the enzyme properties and the initial hydrogel design, the temporal and spatial changes in gel cross-linking are dramatically impacted, a feature that is likely to strongly affect new tissue development. PMID:21809945

  12. Inhibitory effects of mast cell-mediated allergic reactions by cell cultured Siberian Ginseng.

    PubMed

    Jeong, H J; Koo, H N; Myung, N I; Shin, M K; Kim, J W; Kim, D K; Kim, K S; Kim, H M; Lee, Y M

    2001-02-01

    The crude drug "Siberian Ginseng (SG)" has long been used in empirical Oriental medicine for the nonspecific enhancement of resistance in humans and animals. In this study, we investigated the effect of cell cultured SG by oral administration in mast cell-mediated allergic reactions. SG dose-dependently inhibited compound 48/80-induced systemic allergy with doses of 10(-2) to 1 g/kg 1 h before oral administration. Of special note, SG inhibited systemic allergy with the dose of 1 g/kg by 25%. SG (1 g/kg) also inhibited passive cutaneous allergic reaction by 51%. SG dose-dependently inhibited histamine release from rat peritoneal mast cells. When SG (0.01 mg/ml) was added, the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 in antidinitrophenyl (DNP) IgE antibody-stimulated mast cells was inhibited 39.5% and 23.3%, respectively. In addition, SG inhibited anti-DNP IgE antibody-stimulated TNF-alpha protein expression in mast cells. Our studies provide evidence that SG may be beneficial in the treatment of various types of allergic diseases.

  13. CXCR5⁺ T helper cells mediate protective immunity against tuberculosis.

    PubMed

    Slight, Samantha R; Rangel-Moreno, Javier; Gopal, Radha; Lin, Yinyao; Fallert Junecko, Beth A; Mehra, Smriti; Selman, Moises; Becerril-Villanueva, Enrique; Baquera-Heredia, Javier; Pavon, Lenin; Kaushal, Deepak; Reinhart, Todd A; Randall, Troy D; Khader, Shabaana A

    2013-02-01

    One third of the world's population is infected with Mycobacterium tuberculosis (Mtb). Although most infected people remain asymptomatic, they have a 10% lifetime risk of developing active tuberculosis (TB). Thus, the current challenge is to identify immune parameters that distinguish individuals with latent TB from those with active TB. Using human and experimental models of Mtb infection, we demonstrated that organized ectopic lymphoid structures containing CXCR5+ T cells were present in Mtb-infected lungs. In addition, we found that in experimental Mtb infection models, the presence of CXCR5+ T cells within ectopic lymphoid structures was associated with immune control. Furthermore, in a mouse model of Mtb infection, we showed that activated CD4+CXCR5+ T cells accumulated in Mtb-infected lungs and produced proinflammatory cytokines. Mice deficient in Cxcr5 had increased susceptibility to TB due to defective T cell localization within the lung parenchyma. We demonstrated that CXCR5 expression in T cells mediated correct T cell localization within TB granulomas, promoted efficient macrophage activation, protected against Mtb infection, and facilitated lymphoid follicle formation. These data demonstrate that CD4+CXCR5+ T cells play a protective role in the immune response against TB and highlight their potential use for future TB vaccine design and therapy.

  14. Dynamics of an HIV-1 infection model with cell mediated immunity

    NASA Astrophysics Data System (ADS)

    Yu, Pei; Huang, Jianing; Jiang, Jiao

    2014-10-01

    In this paper, we study the dynamics of an improved mathematical model on HIV-1 virus with cell mediated immunity. This new 5-dimensional model is based on the combination of a basic 3-dimensional HIV-1 model and a 4-dimensional immunity response model, which more realistically describes dynamics between the uninfected cells, infected cells, virus, the CTL response cells and CTL effector cells. Our 5-dimensional model may be reduced to the 4-dimensional model by applying a quasi-steady state assumption on the variable of virus. However, it is shown in this paper that virus is necessary to be involved in the modeling, and that a quasi-steady state assumption should be applied carefully, which may miss some important dynamical behavior of the system. Detailed bifurcation analysis is given to show that the system has three equilibrium solutions, namely the infection-free equilibrium, the infectious equilibrium without CTL, and the infectious equilibrium with CTL, and a series of bifurcations including two transcritical bifurcations and one or two possible Hopf bifurcations occur from these three equilibria as the basic reproduction number is varied. The mathematical methods applied in this paper include characteristic equations, Routh-Hurwitz condition, fluctuation lemma, Lyapunov function and computation of normal forms. Numerical simulation is also presented to demonstrate the applicability of the theoretical predictions.

  15. Natural cell-mediated cytotoxicity: possible role of N-linked glycoproteins

    SciTech Connect

    Oeltmann, T.N.; Chambers, W.H.

    1986-05-01

    The authors have examined the role of N-linked glycoproteins in natural cell-mediated cytotoxicity (NCMC) by treating effector cells or target cells with swainsonine, a specific inhibitor of golgi mannosidase II which is critical for N-linked glycoprotein processing. They have also examined the effects of alpha-mannosidase, an exoglycosidase specific for alpha-linked mannose residues, on both target and effector cells. Pretreatment of nonadherent mononuclear cells with swainsonine (18 hr) resulted in an inhibition of lysis of K-562 target cells as measured by LDH release. Protein synthesis was not inhibited as measured by incorporation of /sup 14/C-amino acids. However, oligosaccharide processing was altered as measured by incorporation of 2(/sup 3/H)-mannose. Similar treatment did not inhibit target cell-effector cell conjugation. Pretreatment of nonadherent mononuclear cells with alpha-mannosidase (1 hr) did not result in a reduction in NK cell function. However, alpha-mannosidase did cause a release of mannose from treated cells. These results suggest that N-linked glycoproteins may play a role in NCMC, but not at the level of recognition and binding.

  16. Natural cell-mediated cytotoxicity: possible role of N-linked glycoproteins

    SciTech Connect

    Chambers, W.H.; Oeltmann, T.N.

    1986-03-01

    The authors have examined the role of N-linked glycoproteins in natural cell-mediated cytotoxicity (NCMC) by treating effector cells or target cells with swainsonine, a specific inhibitor of golgi mannosidase II which is critical for N-linked glycoprotein processing. They have also examined the effects of alpha-mannosidase, an exoglycosidase specific for alpha-linked mannose residues, on both target and effector cells. Pretreatment of nonadherent mononuclear cells with swainsonine (18 hr) resulted in an inhibition of lysis of K-562 target cells as measured by LDH release. Protein synthesis was not inhibited as measured by incorporation of /sup 14/C-amino acids. However, oligosaccharide processing was altered as measured by incorporation of 2(/sup 3/H)-mannose. Similar treatment did not inhibit target cell-effector cell conjugation. Pretreatment of nonadherent mononuclear cells with alpha-mannosidase (1 hr) did not result in a reduction in NK cell function. However, alpha-mannosidase did cause a release of mannose from treated cells. These results suggest that N-linked glycoproteins may play a role in NCMC, but not at the level of recognition and binding.

  17. Srf-dependent paracrine signals produced by myofibers control satellite cell-mediated skeletal muscle hypertrophy.

    PubMed

    Guerci, Aline; Lahoute, Charlotte; Hébrard, Sophie; Collard, Laura; Graindorge, Dany; Favier, Maryline; Cagnard, Nicolas; Batonnet-Pichon, Sabrina; Précigout, Guillaume; Garcia, Luis; Tuil, David; Daegelen, Dominique; Sotiropoulos, Athanassia

    2012-01-04

    Adult skeletal muscles adapt their fiber size to workload. We show that serum response factor (Srf) is required for satellite cell-mediated hypertrophic muscle growth. Deletion of Srf from myofibers and not satellite cells blunts overload-induced hypertrophy, and impairs satellite cell proliferation and recruitment to pre-existing fibers. We reveal a gene network in which Srf within myofibers modulates interleukin-6 and cyclooxygenase-2/interleukin-4 expressions and therefore exerts a paracrine control of satellite cell functions. In Srf-deleted muscles, in vivo overexpression of interleukin-6 is sufficient to restore satellite cell proliferation but not satellite cell fusion and overall growth. In contrast cyclooxygenase-2/interleukin-4 overexpression rescue satellite cell recruitment and muscle growth without affecting satellite cell proliferation, identifying altered fusion as the limiting cellular event. These findings unravel a role for Srf in the translation of mechanical cues applied to myofibers into paracrine signals, which in turn will modulate satellite cell functions and support muscle growth.

  18. The 3 major types of innate and adaptive cell-mediated effector immunity.

    PubMed

    Annunziato, Francesco; Romagnani, Chiara; Romagnani, Sergio

    2015-03-01

    The immune system has tailored its effector functions to optimally respond to distinct species of microbes. Based on emerging knowledge on the different effector T-cell and innate lymphoid cell (ILC) lineages, it is clear that the innate and adaptive immune systems converge into 3 major kinds of cell-mediated effector immunity, which we propose to categorize as type 1, type 2, and type 3. Type 1 immunity consists of T-bet(+) IFN-γ-producing group 1 ILCs (ILC1 and natural killer cells), CD8(+) cytotoxic T cells (TC1), and CD4(+) TH1 cells, which protect against intracellular microbes through activation of mononuclear phagocytes. Type 2 immunity consists of GATA-3(+) ILC2s, TC2 cells, and TH2 cells producing IL-4, IL-5, and IL-13, which induce mast cell, basophil, and eosinophil activation, as well as IgE antibody production, thus protecting against helminthes and venoms. Type 3 immunity is mediated by retinoic acid-related orphan receptor γt(+) ILC3s, TC17 cells, and TH17 cells producing IL-17, IL-22, or both, which activate mononuclear phagocytes but also recruit neutrophils and induce epithelial antimicrobial responses, thus protecting against extracellular bacteria and fungi. On the other hand, type 1 and 3 immunity mediate autoimmune diseases, whereas type 2 responses can cause allergic diseases.

  19. Is cell-mediated immunity related to the evolution of life-history strategies in birds?

    PubMed Central

    Tella, José L; Scheuerlein, Alex; Ricklefs, Robert E

    2002-01-01

    According to life-history theory, the development of immune function should be balanced through evolutionary optimization of the allocation of resources to reproduction and through mechanisms that promote survival. We investigated interspecific variability in cell-mediated immune response (CMI), as measured by the phytohaemagglutinin (PHA) assay, in relation to clutch size, longevity and other life-history traits in 50 species of birds. CMI exhibited significant repeatability within species, and PHA responses in chicks were consistently stronger than in adults. Univariate tests showed a variety of significant relationships between the CMI of both chicks and adults with respect to size, development period and lifespan, but not clutch size or prevalence of blood parasites in adults. Multivariate analyses confirmed these patterns but independent variables were too highly correlated to isolate unique influences on CMI. The positive relationship of chick CMI to nestling period is further complicated by a parallel relationship of chick CMI to the age at testing. However, multivariate analysis showed that chick CMI varies uniquely with length of the nestling period. Adult CMI was associated with a strong life-history axis of body size, development rate and longevity. Therefore, adult CMI may be associated with prevention and repair mechanisms related to long lifespan, but it also may be allometrically related to body size through other pathways. Neither chick CMI nor adult CMI was related to clutch size, contradicting previous results linking parasite-related mortality to CMI and the evolution of clutch size (reproductive investment) in birds. PMID:12028764

  20. Tumor immunogenicity determines the effect of B7 costimulation on T cell-mediated tumor immunity

    PubMed Central

    1994-01-01

    A costimulatory signal through B7 to its counter-receptor CD28 on T cells enhances T cell activation. We have generated recombinant retroviruses containing cDNA for murine B7 and transduced a panel of murine tumor lines with varying immunogenicity to study the effect of B7 costimulation on antitumor immunity. In contrast to the progressive outgrowth of all wild-type (B7-) tumors in unimmunized syngeneic mice, four immunogenic tumors, lymphoma RMA, EL4, mastocytoma P815, and melanoma E6B2, regressed completely when transduced with the B7 gene. In contrast, four nonimmunogenic tumors, sarcomas MCA101, MCA102, and Ag104, and melanoma B16, remained tumorigenic after transduction of the B7 gene. Immunization with B7-transduced immunogenic tumors enhanced protective immunity and increased specific cytotoxic T lymphocyte (CTL) activity against the respective wild-type tumors as compared to immunization with nontransduced or mock-transduced tumors. Moreover, cocultivation of CTL with B7-transduced EL4 cells augmented the specificity of tumor-reactive CTL in long-term cultures. Treatment by injection of B7-transduced tumor cells cured 60% of mice with established wild-type EL4 lymphoma. In contrast, immunization with nonimmunogenic tumors transduced with B7 did not provide protective immunity and did not increase specific CTL activity. Our results show that tumor immunogenicity is critical to the outcome of costimulation of T cell-mediated tumor immunity by B7. PMID:7507508

  1. Activation by SLAM Family Receptors Contributes to NK Cell Mediated "Missing-Self" Recognition.

    PubMed

    Alari-Pahissa, Elisenda; Grandclément, Camille; Jeevan-Raj, Beena; Leclercq, Georges; Veillette, André; Held, Werner

    2016-01-01

    Natural Killer (NK) cells attack normal hematopoietic cells that do not express inhibitory MHC class I (MHC-I) molecules, but the ligands that activate NK cells remain incompletely defined. Here we show that the expression of the Signaling Lymphocyte Activation Molecule (SLAM) family members CD48 and Ly9 (CD229) by MHC-I-deficient tumor cells significantly contributes to NK cell activation. When NK cells develop in the presence of T cells or B cells that lack inhibitory MHC-I but express activating CD48 and Ly9 ligands, the NK cells' ability to respond to MHC-I-deficient tumor cells is severely compromised. In this situation, NK cells express normal levels of the corresponding activation receptors 2B4 (CD244) and Ly9 but these receptors are non-functional. This provides a partial explanation for the tolerance of NK cells to MHC-I-deficient cells in vivo. Activating signaling via 2B4 is restored when MHC-I-deficient T cells are removed, indicating that interactions with MHC-I-deficient T cells dominantly, but not permanently, impair the function of the 2B4 NK cell activation receptor. These data identify an important role of SLAM family receptors for NK cell mediated "missing-self" reactivity and suggest that NK cell tolerance in MHC-I mosaic mice is in part explained by an acquired dysfunction of SLAM family receptors.

  2. Hypothalamus-Pituitary-Adrenal cell-mediated immunity regulation in the Immune Restoration Inflammatory Syndrome

    PubMed Central

    Khakshooy, Allen; Chiappelli, Francesco

    2016-01-01

    Over one third of the patients sero-positive for the human immunodeficiency virus (HIV) with signs of the acquired immune deficiency syndrome (AIDS), and under treatment with anti-retroviral therapy (ART), develop the immune reconstitution inflammatory syndrome (IRIS). It is not clear what variables are that determine whether a patient with HIV/AIDS will develop ART-related IRIS, but the best evidence base thus far indicates that HIV/AIDS patients with low CD4 cell count, and HIV/AIDS patients whose CD4 count recovery shows a sharp slope, suggesting a particularly fast "immune reconstitution", are at greater risk of developing IRIS. Here, we propose the hypothesis that one important variable that can contribute to low CD4 cell count number and function in ART-treated HIV/AIDS patients is altered hypothalamic-pituitary-adrenal (HPA) cell-mediated immune (CMI) regulation. We discuss HPA-CMI deregulation in IRIS as the new frontier in comparative effectiveness research (CRE) for obtaining and utilizing the best evidence base for treatment of patients with HIV/AIDS in specific clinical settings. We propose that our hypothesis about altered HPA-CMI may extend to the pathologies observed in related viral infection, including Zika PMID:27212842

  3. IL-9 regulates intestinal barrier function in experimental T cell-mediated colitis

    PubMed Central

    Gerlach, Katharina; McKenzie, Andrew N; Neurath, Markus F; Weigmann, Benno

    2015-01-01

    As previous studies suggested that IL-9 may control intestinal barrier function, we tested the role of IL-9 in experimental T cell-mediated colitis induced by the hapten reagent 2,4,6-trinitrobenzenesulfonic acid (TNBS). The deficiency of IL-9 suppressed TNBS-induced colitis and led to lower numbers of PU.1 expressing T cells in the lamia propria, suggesting a regulatory role for Th9 cells in the experimental TNBS colitis model. Since IL-9 is known to functionally alter intestinal barrier function in colonic inflammation, we assessed the expression of tight junction molecules in intestinal epithelial cells of TNBS-inflamed mice. Therefore we made real-time PCR analyses for tight junction molecules in the inflamed colon from wild-type and IL-9 KO mice, immunofluorescent stainings and investigated the expression of junctional proteins directly in intestinal epithelial cells of TNBS-inflamed mice by Western blot studies. The results demonstrated that sealing proteins like occludin were up regulated in the colon of inflamed IL-9 KO mice. In contrast, the tight junction protein Claudin1 showed lower expression levels when IL-9 is absent. Surprisingly, the pore-forming molecule Claudin2 revealed equal expression in TNBS-treated wild-type and IL-9-deficient animals. These results illustrate the pleiotropic functions of IL-9 in changing intestinal permeability in experimental colitis. Thus, modulation of IL-9 function emerges as a new approach for regulating barrier function in intestinal inflammation. PMID:25838986

  4. Micro-RNA dysregulation in multiple sclerosis favours pro-inflammatory T-cell-mediated autoimmunity.

    PubMed

    Guerau-de-Arellano, Mireia; Smith, Kristen M; Godlewski, Jakub; Liu, Yue; Winger, Ryan; Lawler, Sean E; Whitacre, Caroline C; Racke, Michael K; Lovett-Racke, Amy E

    2011-12-01

    Pro-inflammatory T cells mediate autoimmune demyelination in multiple sclerosis. However, the factors driving their development and multiple sclerosis susceptibility are incompletely understood. We investigated how micro-RNAs, newly described as post-transcriptional regulators of gene expression, contribute to pathogenic T-cell differentiation in multiple sclerosis. miR-128 and miR-27b were increased in naïve and miR-340 in memory CD4(+) T cells from patients with multiple sclerosis, inhibiting Th2 cell development and favouring pro-inflammatory Th1 responses. These effects were mediated by direct suppression of B lymphoma Mo-MLV insertion region 1 homolog (BMI1) and interleukin-4 (IL4) expression, resulting in decreased GATA3 levels, and a Th2 to Th1 cytokine shift. Gain-of-function experiments with these micro-RNAs enhanced the encephalitogenic potential of myelin-specific T cells in experimental autoimmune encephalomyelitis. In addition, treatment of multiple sclerosis patient T cells with oligonucleotide micro-RNA inhibitors led to the restoration of Th2 responses. These data illustrate the biological significance and therapeutic potential of these micro-RNAs in regulating T-cell phenotypes in multiple sclerosis.

  5. Architecture of apical dendrites in the murine neocortex: dual apical dendritic systems.

    PubMed

    Escobar, M I; Pimienta, H; Caviness, V S; Jacobson, M; Crandall, J E; Kosik, K S

    1986-04-01

    A monoclonal antibody (5F9) against microtubule-associated protein 2 is a selective and sensitive marker for neocortical dendrites in the mouse. The marker stains all dendrites. It affords a particularly comprehensive picture of the patterns of arrangements of apical dendrites which are most intensely stained with this antibody. Dual systems of apical dendrites arise from the polymorphic neurons of layer VI, on the one hand, and the pyramidal neurons of layers II-V, on the other. Terminal arborization of the former is concentrated principally at the interface of layers V and IV, while that of the latter is in the molecular layer. Apical dendrites of both systems are grouped into fascicles. In supragranular layers and in upper layer VI-lower layer V, where apical dendrites are most abundant, the fascicles coalesce into septa. These generate a honeycomb-like pattern, subdividing these cortical levels into columnar spaces of approximately 20-40 micron diameter. At the level of layer IV, where the number of apical dendrites is greatly reduced, the fascicles are isolated bundles. These bundles have the form of circular, elliptical or rectangular columns in the primary somatosensory, temporal and frontal regions, respectively. Those in the barrel field are preferentially concentrated in the sides of barrels and the interbarrel septa. The configurations of the dendritic fascicles, particularly the midcortical bundles, may conform to the spatial configuration of investing axons of interneurons.

  6. Unmasking targets of T cell-mediated antitumor immunity through high-throughput antigen profiling

    PubMed Central

    Battaglia, Sebastiano; Muhitch, Jason B

    2017-01-01

    More than three decades of evidence has established that antitumor immune responses, initially shown with IL-2 treatment, can result in complete, durable eradication of malignant disease in metastatic patients. Recent studies have demonstrated that immune checkpoint blockade as well as cellular therapies, including dendritic cell activation of T cells and adoptive T cell transfer, can induce long-lasting responses. To elicit cytolysis of tumor cells, effector T cells rely on tumor expression of target antigens. However, the antigens targeted during antitumor responses are largely unknown. Technological advancements and availability of sequencing data have paved the way for more efficient screening and validation of tumor-associated antigens and neoantigens derived from non-synonymous mutations targeted by T cells under baseline conditions and in the context of immunotherapy. PMID:27010105

  7. [Melanoma immunotherapy: dendritic cell vaccines].

    PubMed

    Lozada-Requena, Ivan; Núñez, César; Aguilar, José Luis

    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 of tumors. Knowing the biology and role has led to generate in vitro several prospects of autologous cell vaccines against diverse types of cancer in humans and animal models. However, given the low efficiency they have shown, we must implement strategies to enhance their natural capacity either through the coexpression of key molecules to activate or reactivate the immune system, in combination with biosimilars or chemotherapeutic drugs. The action of natural products as alternative or adjuvant immunostimulant should not be ruled out. All types of immunotherapy should measure the impact of myeloid suppressor cells, which can attack the immune system and help tumor progression, respectively. This can reduce the activity of cellular vaccines and/or their combinations, that could be the difference between success or not of the immunotherapy. Although for melanoma there exist biosimilars approved by the Food and Drug Administration (FDA), not all have the expected success. Therefore it is necessary to evaluate other strategies including cellular vaccines loaded with tumor antigenic peptides expressed exclusively or antigens from tumor extracts and their respective adjuvants.

  8. The bHLH-PAS protein Spineless is necessary for the diversification of dendrite morphology of Drosophila dendritic arborization neurons

    PubMed Central

    Kim, Michael D.; Jan, Lily Yeh; Jan, Yuh Nung

    2006-01-01

    Dendrites exhibit a wide range of morphological diversity, and their arborization patterns are critical determinants of proper neural connectivity. How different neurons acquire their distinct dendritic branching patterns during development is not well understood. Here we report that Spineless (Ss), the Drosophila homolog of the mammalian aryl hydrocarbon (dioxin) receptor (Ahr), regulates dendrite diversity in the dendritic arborization (da) sensory neurons. In loss-of-function ss mutants, class I and II da neurons, which are normally characterized by their simple dendrite morphologies, elaborate more complex arbors, whereas the normally complex class III and IV da neurons develop simpler dendritic arbors. Consequently, different classes of da neurons elaborate dendrites with similar morphologies. In its control of dendritic diversity among da neurons, ss likely acts independently of its known cofactor tango and through a regulatory program distinct from those involving cut and abrupt. These findings suggest that one evolutionarily conserved role for Ahr in neuronal development concerns the diversification of dendrite morphology. PMID:17015425

  9. Dendritic cell-based immunotherapy induces transient clinical response in advanced rat fibrosarcoma - comparison with preventive anti-tumour vaccination.

    PubMed

    Kucera, A; Pýcha, K; Pajer, P; Spísek, R; Skába, R

    2009-01-01

    In this study we present the models of preventive and therapeutic vaccination of sarcoma-bearing rats with dendritic cells that present tumour antigens from killed tumour cells. We present the characteristics of dendritic cell-based vaccine and its capacity to induce anti-tumour immune response both in vitro and in vivo. We show that preventive vaccination efficiently prevents tumour growth. On the other hand, vaccination of rats with established tumours did not lead to eradication of the tumours. Despite the induction of a vigorous immune response after administration of dendritic cell-based vaccine and transient decrease in tumour progression, tumours eventually resumed their growth and animals vaccinated with dendritic cells succumbed to cancer. In both settings, preventive and therapeutic, dendritic cell-based vaccination induced a vigorous tumour-specific T-cell response. These results argue for the timing of cancer immunotherapy to the stages of low tumour load. Immunotherapy initiated at the stage of minimal residual disease, after reduction of tumour load by other modalities, will have much better chance to offer a clinical benefit to cancer patients than the immunotherapy at the stage of metastatic disease.

  10. Molecules and mechanisms of dendrite development in Drosophila.

    PubMed

    Corty, Megan M; Matthews, Benjamin J; Grueber, Wesley B

    2009-04-01

    Neurons are one of the most morphologically diverse cell types, in large part owing to their intricate dendrite branching patterns. Dendrites are structures that are specialized to receive and process inputs in neurons, thus their specific morphologies reflect neural connectivity and influence information flow through circuits. Recent studies in Drosophila on the molecular basis of dendrite diversity, dendritic guidance, the cell biology of dendritic branch patterning and territory formation have identified numerous intrinsic and extrinsic cues that shape diverse features of dendrites. As we discuss in this review, many of the mechanisms that are being elucidated show conservation in diverse systems.

  11. Accessory Cell Mediated Activation of Porcine NK Cells by TLR7 and TLR8 Agonists

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The induction of innate immune responses by toll-like receptor (TLR) agonists is the subject of intense investigation in many different species. In large part, this reflects the potential of such compounds to be effective vaccine adjuvants. For that reason, we analyzed the activation of innate cells...

  12. Characterization of chicken epidermal dendritic cells

    PubMed Central

    Igyártó, Botond-Zoltán; Lackó, Erzsébet; Oláh, Imre; Magyar, Attila

    2006-01-01

    It has been known for 15 years that the chicken epidermis contains ATPase+ and major histocompatibility complex class II-positive (MHCII+) dendritic cells. These cells were designated as Langerhans cells but neither their detailed phenotype nor their function was further investigated. In the present paper we demonstrate a complete overlapping of ATPase, CD45 and vimentin staining in all dendritic cells of the chicken epidermis. The CD45+ ATPase+ vimentin+ dendritic cells could be divided into three subpopulations: an MHCII+ CD3– KUL01+ and 68.1+ (monocyte-macrophage subpopulation markers) subpopulation, an MHCII– CD3– KUL01– and 68.1– subpopulation and an MHCII– CD3+ KUL01– and 68.1– subpopulation. The first population could be designated as chicken Langerhans cells. The last population represents CD4– CD8– T-cell receptor-αβ– and -γδ– natural killer cells with cytoplasmic CD3 positivity. The epidermal dendritic cells have a low proliferation rate as assessed by bromodeoxyuridine incorporation. Both in vivo and in vitro experiments showed that dendritic cells could be mobilized from the epidermis. Hapten treatment of epidermis resulted in the decrease of the frequency of epidermal dendritic cells and hapten-loaded dendritic cells appeared in the dermis or in in vitro culture of isolated epidermis. Hapten-positive cells were also found in the so-called dermal lymphoid nodules. We suggest that these dermal nodules are responsible for some regional immunological functions similar to the mammalian lymph nodes. PMID:16889640

  13. Dendritic spine dysgenesis in neuropathic pain.

    PubMed

    Tan, Andrew M; Waxman, Stephen G

    2015-08-05

    Neuropathic pain is a significant unmet medical need in patients with variety of injury or disease insults to the nervous system. Neuropathic pain often presents as a painful sensation described as electrical, burning, or tingling. Currently available treatments have limited effectiveness and narrow therapeutic windows for safety. More powerful analgesics, e.g., opioids, carry a high risk for chemical dependence. Thus, a major challenge for pain research is the elucidation of the mechanisms that underlie neuropathic pain and developing targeted strategies to alleviate pathological pain. The mechanistic link between dendritic spine structure and circuit function could explain why neuropathic pain is difficult to treat, since nociceptive processing pathways are adversely "hard-wired" through the reorganization of dendritic spines. Several studies in animal models of neuropathic pain have begun to reveal the functional contribution of dendritic spine dysgenesis in neuropathic pain. Previous reports have demonstrated three primary changes in dendritic spine structure on nociceptive dorsal horn neurons following injury or disease, which accompany chronic intractable pain: (I) increased density of dendritic spines, particularly mature mushroom-spine spines, (II) redistribution of spines toward dendritic branch locations close to the cell body, and (III) enlargement of the spine head diameter, which generally presents as a mushroom-shaped spine. Given the important functional implications of spine distribution, density, and shape for synaptic and neuronal function, the study of dendritic spine abnormality may provide a new perspective for investigating pain, and the identification of specific molecular players that regulate spine morphology may guide the development of more effective and long-lasting therapies.

  14. Two sides of one coin: massive hepatic necrosis and progenitor cell-mediated regeneration in acute liver failure

    PubMed Central

    Weng, Hong-Lei; Cai, Xiaobo; Yuan, Xiaodong; Liebe, Roman; Dooley, Steven; Li, Hai; Wang, Tai-Ling

    2015-01-01

    Massive hepatic necrosis is a key event underlying acute liver failure, a serious clinical syndrome with high mortality. Massive hepatic necrosis in acute liver failure has unique pathophysiological characteristics including extremely rapid parenchymal cell death and removal. On the other hand, massive necrosis rapidly induces the activation of liver progenitor cells, the so-called “second pathway of liver regeneration.” The final clinical outcome of acute liver failure depends on whether liver progenitor cell-mediated regeneration can efficiently restore parenchymal mass and function within a short time. This review summarizes the current knowledge regarding massive hepatic necrosis and liver progenitor cell-mediated regeneration in patients with acute liver failure, the two sides of one coin. PMID:26136687

  15. Receptor binding and cell-mediated metabolism of (/sup 125/I)monoiodoglucagon by isolated canine hepatocytes

    SciTech Connect

    Hagopian, W.A.; Tager, H.S.

    1984-07-25

    A reverse-phase HPLC method has been developed to purify /sup 125/I-labeled products resulting from the chloramine-T-based iodination of glucagon. In addition the products ((/sup 125/I)iodoTyr/sup 10/ /sup 13/)glucagon, ((/sup 125/I)iodoTyr/sup 13/)glucagon, and ((/sup 125/I)iodoTyr/sup 10/)glucagon) have been used to study the receptor binding of glucagon and the cell-mediated metabolism of the hormone by isolated canine hepatocytes. It was concluded that (a) not withstanding apparent differences in affinities exhibited by the three peptides, the interactions with the glucagon receptor are functionally equivalent, and (b) the cell-mediated metabolism of receptor-bound glucagon involves the formation of hormone-derived peptides in which the biologically important NH/sub 2/-terminal region of the hormone has been modified by limited proteolytic cleavage.

  16. Influence of brachytherapy ( sup 192 Ir afterloading) on cell-mediated immune reactions in patients with stage I endometrial cancer

    SciTech Connect

    Gerstner, G.J.; Kucera, H.; Kudlacek, S.; Micksche, M. )

    1989-11-01

    The influence of radiation therapy on cell-mediated immune reactions in cancer patients seems to depend on source, dose, and area of irradiation, as well as on the variables reflected by the patient population investigated. In the present study we demonstrated that brachytherapy ({sup 192}Ir afterloading), applied to patients with inoperable stage I endometrial cancer, has no immediate or sustained effect on lymphocyte function. Both lymphocyte mitogen response and natural killer cell (NK) activity are not significantly changed in terms of baseline values compared with test results during and after therapy. Brachytherapy, as used in this study, has no influence on cell-mediated immunity in patients with endometrial cancer stage I.

  17. Effect of Lactobacillus brevis KB290 on the cell-mediated cytotoxic activity of mouse splenocytes: a DNA microarray analysis.

    PubMed

    Fukui, Yuichiro; Sasaki, Erika; Fuke, Nobuo; Nakai, Yuji; Ishijima, Tomoko; Abe, Keiko; Yajima, Nobuhiro

    2013-11-14

    Lactic acid bacteria confer a variety of health benefits. Here, we investigate the mechanisms by which Lactobacillus brevis KB290 (KB290) enhances cell-mediated cytotoxic activity. Female BALB/c mice aged 9 weeks were fed a diet containing KB290 (3 × 10(9) colony-forming units/g) or starch for 1 d. The resulting cytotoxic activity of splenocytes against YAC-1 cells was measured using flow cytometry and analysed for gene expression using DNA microarray technology. KB290 enhanced the cell-mediated cytotoxic activity of splenocytes. DNA microarray analysis identified 327 up-regulated and 347 down-regulated genes that characterised the KB290 diet group. The up-regulated genes were significantly enriched in Gene Ontology terms related to immunity, and, especially, a positive regulation of T-cell-mediated cytotoxicity existed among these terms. Almost all the genes included in the term encoded major histocompatibility complex (MHC) class I molecules involved in the presentation of antigen to CD8(+) cytotoxic T cells. Marco and Signr1 specific to marginal zone macrophages (MZM), antigen-presenting cells, were also up-regulated. Flow cytometric analysis confirmed that the proportion of MZM was significantly increased by KB290 ingestion. Additionally, the over-represented Kyoto Encyclopedia of Genes and Genomes pathways among the up-regulated genes were those for natural killer (NK) cell-mediated cytotoxicity and antigen processing and presentation. The results for the selected genes associated with NK cells and CD8(+) cytotoxic T cells were confirmed by quantitative RT-PCR. These results suggest that enhanced cytotoxic activity could be caused by the activation of NK cells and/or of CD8(+) cytotoxic T cells stimulated via MHC class I presentation.

  18. Seasonal trade-offs in cell-mediated immunosenescence in ruffs (Philomachus pugnax).

    PubMed Central

    Lozano, George A; Lank, David B

    2003-01-01

    The immune system is an energetically expensive self-maintenance complex that, given the risks of parasitism, cannot be carelessly compromised. Life-history theory posits that trade-offs between fitness components, such as self-maintenance and reproduction, vary between genders and age classes depending on their expected residual lifetime reproductive success, and seasonally as energetic requirements change. Using ruff (Philomachus pugnax), a bird with two genetically distinct male morphs, we demonstrate here a decrease in male immunocompetence during the breeding season, greater variance in immune response among males than females, immunosenescence in both sexes and male morphs, and a seasonal shift in the age range required to detect senescence. Using a phytohaemagglutinin delayed hypersensitivity assay, we assessed cell-mediated immunity (CMI) of males of typical breeding age during the breeding and nonbreeding seasons, and of a larger sample that included females and birds of a greater age range during the non-breeding period. CMI was higher for breeding-aged males in May than in November, but the increase was not related to age or male morph. In November, mean CMI did not differ between the sexes, but the variance was higher for males than for females, and there were no differences in mean or variance between the two male morphs. For both sexes and male morphs, CMI was lower for young birds than for birds of typical breeding ages, and it declined again for older birds. In males, senescence was detected in the non-breeding season only when very old birds were included. These results, generally consistent with expectations from life-history theory, indicate that the immune system can be involved in multifarious trade-offs within a yearly cycle and along an individual's lifetime, and that specific predictions about means and variances in immune response should be considered in future immunoecological research. PMID:12816660

  19. A Neutralizing Antibody Assay Based on a Reporter of Antibody-Dependent Cell-Mediated Cytotoxicity.

    PubMed

    Wu, Yuling; Li, Jia J; Kim, Hyun Jun; Liu, Xu; Liu, Weiyi; Akhgar, Ahmad; Bowen, Michael A; Spitz, Susan; Jiang, Xu-Rong; Roskos, Lorin K; White, Wendy I

    2015-11-01

    Benralizumab is a humanized anti-IL5 receptor α (IL5Rα) monoclonal antibody (mAb) with enhanced (afucosylation) antibody-dependent cell-mediated cytotoxicity (ADCC) function. An ADCC reporter cell-based neutralizing antibody (NAb) assay was developed and characterized to detect NAb against benralizumab in human serum to support the clinical development of benralizumab. The optimal ratio of target cells to effector cells was 3:1. Neither parental benralizumab (fucosylated) nor benralizumab Fab resulted in ADCC activity, confirming the requirement for ADCC activity in the NAb assay. The serum tolerance of the cells was determined to be 2.5%. The cut point derived from normal and asthma serum samples was comparable. The effective range of benralizumab was determined, and 35 ng/mL [80% maximal effective concentration (EC80)] was chosen as the standard concentration to run in the assessment of NAb. An affinity purified goat anti-benralizumab polyclonal idiotype antibody preparation was shown to have NAb since it inhibited ADCC activity in a dose-dependent fashion. The low endogenous concentrations of IL5 and soluble IL5 receptor (sIL5R) did not demonstrate to interfere with the assay. The estimated assay sensitivities at the cut point were 1.02 and 1.10 μg/mL as determined by the surrogate neutralizing goat polyclonal and mouse monoclonal anti-drug antibody (ADA) controls, respectively. The assay can detect NAb (at 2.5 μg/mL) in the presence of 0.78 μg/mL benralizumab. The assay was not susceptible to non-specific matrix effects. This study provides an approach and feasibility of developing an ADCC cell-based NAb assay to support biopharmaceuticals with an ADCC function.

  20. Anti-allergic effects of Lycopus lucidus on mast cell-mediated allergy model

    SciTech Connect

    Shin, Tae-Yong . E-mail: tyshin@woosuk.ac.kr; Kim, Sang-Hyun; Suk, Kyoungho; Ha, Jeoung-Hee; Kim, InKyeom; Lee, Maan-Gee; Jun, Chang-Duk; Kim, Sang-Yong; Lim, Jong-Pil; Eun, Jae-Soon; Shin, Hye-Young; Kim, Hyung-Min

    2005-12-15

    The current study characterizes the mechanism by which the aqueous extract of Lycopus lucidus Turcz. (Labiatae) (LAE) decreases mast cell-mediated immediate-type allergic reaction. The immediate-type allergic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. LAE has been used as a traditional medicine in Korea and is known to have an anti-inflammatory effect. However, its specific mechanism of action is still unknown. LAE was anally administered to mice for high and fast absorption. LAE inhibited compound 48/80-induced systemic reactions in mice. LAE decreased the local allergic reaction, passive cutaneous anaphylaxis, activated by anti-dinitrophenyl (DNP) IgE antibody. LAE dose-dependently reduced histamine release from rat peritoneal mast cells activated by compound 48/80 or anti-DNP IgE. Furthermore, LAE decreased the secretion of TNF-{alpha} and IL-6 in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated human mast cells. The inhibitory effect of LAE on the pro-inflammatory cytokine was p38 mitogen-activated protein kinase (MAPK) and nuclear factor-{kappa}B (NF-{kappa}B) dependent. LAE attenuated PMA plus A23187-induced degradation of I{kappa}B{alpha} and nuclear translocation of NF-{kappa}B, and specifically blocked activation of p38 MAPK, but not that of c-jun N-terminal kinase and extracellular signal-regulated kinase. Our findings provide evidence that LAE inhibits mast cell-derived immediate-type allergic reactions and involvement of pro-inflammatory cytokines, p38 MAPK, and NF-{kappa}B in these effects.

  1. Precision Subtypes of T Cell-Mediated Rejection Identified by Molecular Profiles

    PubMed Central

    Kadota, Paul Ostrom; Hajjiri, Zahraa; Finn, Patricia W.; Perkins, David L.

    2015-01-01

    Among kidney transplant recipients, the treatment of choice for acute T cell-mediated rejection (TCMR) with pulse steroids or antibody protocols has variable outcomes. Some rejection episodes are resistant to an initial steroid pulse, but respond to subsequent antibody protocols. The biological mechanisms causing the different therapeutic responses are not currently understood. Histological examination of the renal allograft is considered the gold standard in the diagnosis of acute rejection. The Banff Classification System was established to standardize the histopathological diagnosis and to direct therapy. Although widely used, it shows variability among pathologists and lacks criteria to guide precision individualized therapy. The analysis of the transcriptome in allograft biopsies, which we analyzed in this study, provides a strategy to develop molecular diagnoses that would have increased diagnostic precision and assist the development of individualized treatment. Our hypothesis is that the histological classification of TCMR contains multiple subtypes of rejection. Using R language algorithms to determine statistical significance, multidimensional scaling, and hierarchical, we analyzed differential gene expression based on microarray data from biopsies classified as TCMR. Next, we identified KEGG functions, protein–protein interaction networks, gene regulatory networks, and predicted therapeutic targets using the integrated database ConsesnsusPathDB (CPDB). Based on our analysis, two distinct clusters of biopsies termed TCMR01 and TCMR02 were identified. Despite having the same Banff classification, we identified 1933 differentially expressed genes between the two clusters. These genes were further divided into three major groups: a core group contained within both the TCMR01 and TCMR02 subtypes, as well as genes unique to TCMR01 or TCMR02. The subtypes of TCMR utilized different biological pathways, different regulatory networks and were predicted to

  2. Endogenous n-3 Polyunsaturated Fatty Acids Attenuate T Cell-Mediated Hepatitis via Autophagy Activation

    PubMed Central

    Li, Yanli; Tang, Yuan; Wang, Shoujie; Zhou, Jing; Zhou, Jia; Lu, Xiao; Bai, Xiaochun; Wang, Xiang-Yang; Chen, Zhengliang; Zuo, Daming

    2016-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs) exert anti-inflammatory effects in several liver disorders, including cirrhosis, acute liver failure, and fatty liver disease. To date, little is known about their role in immune-mediated liver diseases. In this study, we used fat-1 transgenic mice rich in endogenous n-3 PUFAs to examine the role of n-3 PUFAs in immune-mediated liver injury. Concanavalin A (Con A) was administered intravenously to wild-type (WT) and fat-1 transgenic mice to induce T cell-mediated hepatitis. Reduced liver damage was shown in Con A-administrated fat-1 transgenic mice, as evidenced by decreased mortality, attenuated hepatic necrosis, lessened serum alanine aminotransferase activity, and inhibited production of pro-inflammatory cytokines (e.g., TNF-α, IL-6, IL-17A, and IFN-γ). In vivo and in vitro studies demonstrated that n-3 PUFAs significantly inhibited the activation of hepatic T cells and the differentiation of Th1 cells after Con A challenge. Further studies showed that n-3 PUFAs markedly increased autophagy level in Con A-treated fat-1 T cells compared with the WT counterparts. Blocking hepatic autophagy activity with chloroquine diminished the differences in T cell activation and liver injury between Con A-injected WT and fat-1 transgenic mice. We conclude that n-3 PUFAs limit Con A-induced hepatitis via an autophagy-dependent mechanism and could be exploited as a new therapeutic approach for autoimmune hepatitis. PMID:27679638

  3. Effect of Chicoric Acid on Mast Cell-Mediated Allergic Inflammation in Vitro and in Vivo.

    PubMed

    Lee, Na Young; Chung, Kyung-Sook; Jin, Jong Sik; Bang, Keuk Soo; Eom, Ye-Jin; Hong, Chul-Hee; Nugroho, Agung; Park, Hee-Jun; An, Hyo-Jin

    2015-12-24

    Chicoric acid (dicaffeoyl-tartaric acid), is a natural phenolic compound found in a number of plants, such as chicory (Cichorium intybus) and Echinacea (Echinacea purpurea), which possesses antioxidant, anti-inflammatory, antiviral, and analgesic activities. Although these biological effects of chicoric acid have been investigated, there are no reports of its antiallergic-related anti-inflammatory effects in human mast cells (HMC)-1 or anaphylactic activity in a mouse model. Therefore, we investigated the antiallergic-related anti-inflammatory effect of chicoric acid and its underlying mechanisms of action using phorbol-12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated HMC-1 cells. Chicoric acid decreased the mRNA expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. We studied the inhibitory effects of chicoric acid on the nuclear translocation of nuclear factor kappa B (NF-κB) and activation of caspase-1. However, mitogen-activated protein kinase (MAPK) activation was not sufficient to abrogate the stimulus. In addition, we investigated the ability of chicoric acid to inhibit compound 48/80-induced systemic anaphylaxis in vivo. Oral administration of chicoric acid at 20 mg/kg inhibited histamine release and protected mice against compound 48/80-induced anaphylactic mortality. These results suggest that chicoric acid has an antiallergic-related anti-inflammatory effect that involves modulating mast cell-mediated allergic responses. Therefore, chicoric acid could be an efficacious agent for allergy-related inflammatory disorders.

  4. ISCOM-matrix-based equine influenza (EIV) vaccine stimulates cell-mediated immunity in the horse.

    PubMed

    Paillot, R; Prowse, L

    2012-01-15

    The humoral immune response induced by ISCOM-matrix (Immuno Stimulating COMplex-Matrix)-adjuvanted equine influenza virus (EIV) vaccine is well documented in horses. ISCOM-matrix adjuvanted vaccines against human influenza are strong inducers of cell-mediated immunity (CMI), including T cell proliferation and virus-specific cytotoxic T cell. In the horse, the CMI response to equine influenza vaccination is less well characterised. An ISCOM-based vaccine has been shown to induce interferon gamma (IFN-γ) synthesis, a CMI marker, in the horse, but this has not been shown for the ISCOM-matrix vaccine, which is a different formulation. The objective of this study was to measure EIV-specific IFN-γ synthesis after vaccination with an ISCOM-matrix-adjuvanted EIV vaccine. Equilis Prequenza is a commercialised inactivated EIV vaccine containing purified haemagglutinin (HA) and neuraminidase (NA) subunits adjuvanted with ISCOM-matrix. Six influenza-naïve Welsh mountain ponies were vaccinated twice with Equilis Prequenza at an interval of four weeks. Six control ponies received a placebo of physiological water. EIV-specific IFN-γ synthesis by peripheral blood lymphocytes and the antibody response to a panel of representative EIV isolates were measured prior to and after both injections. Immunisation with the ISCOM-matrix-based EIV vaccine stimulated significant EIV-specific IFN-γ synthesis and EIV-specific single radial haemolysis (SRH) antibody. In conclusion, EIV vaccine adjuvanted with ISCOM-matrix stimulates both antibody and a cellular immune response in the horse.

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

    PubMed

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

    2017-03-01

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

  6. Persistence of cell-mediated immunity three decades after vaccination with the live vaccine strain of Francisella tularensis

    PubMed Central

    Eneslätt, Kjell; Rietz, Cecilia; Rydén, Patrik; Stöven, Svenja; House, Robert V.; Wolfraim, Lawrence A.; Tärnvik, Arne; Sjöstedt, Anders

    2012-01-01

    Summary The efficacy of many vaccines against intracellular bacteria depends on the generation of cell-mediated immunity, but studies to determine the duration of immunity are usually confounded by re-exposure. The causative agent of tularemia, Francisella tularensis, is rare in most areas and, therefore, tularemia vaccination is an interesting model for studies of the longevity of vaccine-induced cell-mediated immunity. Here lymphocyte proliferation and cytokine production in response to F. tularensis were assayed in two groups of 16 individuals, vaccinated 1-3 or 27-34 years previously. As compared to naïve individuals, vaccinees of both groups showed higher proliferative responses and, out of 17 cytokines assayed, higher levels of MIP-1β, IFN-γ, IL-10, and IL-5 in response to recall stimulation. The responses were very similar in the two groups of vaccinees. A statistical model was developed to predict the immune status of the individuals and by use of two parameters, proliferative responses and levels of IFN-γ, 91.1% of the individuals were correctly classified. Using flow cytometry analysis, we demonstrated that during recall stimulation, expression of IFN-γ by CD4+CCR7+, CD4+CD62L+, CD8+CCR7+, and CD8+CD62L+ cells significantly increased in samples from vaccinated donors. In conclusion, cell-mediated immunity was found to persist three decades after tularemia vaccination without evidence of decline. PMID:21442618

  7. The Isothermal Dendritic Growth Experiment (IDGE)

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Koss, M. B.; LaCombe, J. C.; Lupulescu, A. O.; Frei, J. E.; Guimarra, C.; Malarik, D. C.

    2001-01-01

    Dendritic solidification is one of the simplest examples of pattern formation where a structureless melt evolves into a ramified crystalline microstructure; it is a common mode of solidification in many materials, but especially so in metals and alloys. There is considerable engineering interest in dendrites because of the role dendrites play in the determination of microstructure, and thereby in influencing the physical properties of cast metals and alloys. Dendritic solidification provides important examples of non-equilibrium physics, pattern formation dynamics, and models for computational condensed matter and material physics. Current theories of dendritic growth generally couple diffusion effects in the melt with the physics introduced by the interface. Unfortunately, in terrestrial based experiments, convective effects in the melt alter the growth process in such a manner as to prevent definitive analysis of convective, diffusive or interfacial effects. Thus, the effective elimination of convection in the melt by operating experiments on orbit were required to produce high-fidelity data needed for achieving further progress. This simple fact comprised the scientific justification for the IDGE.

  8. Electromagnetic induction methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electromagnetic induction geophysical methods are finding greater and greater use for agricultural purposes. Electromagnetic induction methods measure the electrical conductivity (or resistivity) for a bulk volume of soil directly beneath the surface. An instrument called a ground conductivity meter...

  9. Stimulation of dendritic cells enhances immune response after photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Mroz, Pawel; Castano, Ana P.; Hamblin, Michael R.

    2009-02-01

    Photodynamic therapy (PDT) involves the administration of photosensitizers followed by illumination of the primary tumor with red light producing reactive oxygen species that cause vascular shutdown and tumor cell necrosis and apoptosis. Anti-tumor immunity is stimulated after PDT due to the acute inflammatory response, priming of the immune system to recognize tumor-associated antigens (TAA). The induction of specific CD8+ Tlymphocyte cells that recognize major histocompatibility complex class I (MHC-I) restricted epitopes of TAAs is a highly desirable goal in cancer therapy. The PDT killed tumor cells may be phagocytosed by dendritic cells (DC) that then migrate to draining lymph nodes and prime naÃve T-cells that recognize TAA epitopes. This process is however, often sub-optimal, in part due to tumor-induced DC dysfunction. Instead of DC that can become mature and activated and have a potent antigen-presenting and immune stimulating phenotype, immature dendritic cells (iDC) are often found in tumors and are part of an immunosuppressive milieu including regulatory T-cells and immunosuppressive cytokines such as TGF-beta and IL10. We here report on the use of a potent DC activating agent, an oligonucleotide (ODN) that contains a non-methylated CpG motif and acts as an agonist of toll like receptor (TLR) 9. TLR activation is a danger signal to notify the immune system of the presence of invading pathogens. CpG-ODN (but not scrambled non-CpG ODN) increased bone-marrow DC activation after exposure to PDT-killed tumor cells, and significantly increased tumor response to PDT and mouse survival after peri-tumoral administration. CpG may be a valuable immunoadjuvant to PDT especially for tumors that produce DC dysfunction.

  10. Transcriptomic Analysis of Persistent Infection with Foot-and-Mouth Disease Virus in Cattle Suggests Impairment of Apoptosis and Cell-Mediated Immunity in the Nasopharynx

    PubMed Central

    Stenfeldt, Carolina; Smoliga, George R.; Pacheco, Juan M.; Rodriguez, Luis L.; Li, Robert W.; Zhu, James; Arzt, Jonathan

    2016-01-01

    In order to investigate the mechanisms of persistent foot-and-mouth disease virus (FMDV) infection in cattle, transcriptome alterations associated with the FMDV carrier state were characterized using a bovine whole-transcriptome microarray. Eighteen cattle (8 vaccinated with a recombinant FMDV A vaccine, 10 non-vaccinated) were challenged with FMDV A24 Cruzeiro, and the gene expression profiles of nasopharyngeal tissues collected between 21 and 35 days after challenge were compared between 11 persistently infected carriers and 7 non-carriers. Carriers and non-carriers were further compared to 2 naïve animals that had been neither vaccinated nor challenged. At a controlled false-discovery rate of 10% and a minimum difference in expression of 50%, 648 genes were differentially expressed between FMDV carriers and non-carriers, and most (467) had higher expression in carriers. Among these, genes associated with cellular proliferation and the immune response–such as chemokines, cytokines and genes regulating T and B cells–were significantly overrepresented. Differential gene expression was significantly correlated between non-vaccinated and vaccinated animals (biological correlation +0.97), indicating a similar transcriptome profile across these groups. Genes related to prostaglandin E2 production and the induction of regulatory T cells were overexpressed in carriers. In contrast, tissues from non-carrier animals expressed higher levels of complement regulators and pro-apoptotic genes that could promote virus clearance. Based on these findings, we propose a working hypothesis for FMDV persistence in nasopharyngeal tissues of cattle, in which the virus may be maintained by an impairment of apoptosis and the local suppression of cell-mediated antiviral immunity by inducible regulatory T cells. PMID:27643611

  11. Reduced Purkinje cell dendritic arborization and loss of dendritic spines in essential tremor.

    PubMed

    Louis, Elan D; Lee, Michelle; Babij, Rachel; Ma, Karen; Cortés, Etty; Vonsattel, Jean-Paul G; Faust, Phyllis L

    2014-12-01

    Based on accumulating post-mortem evidence of abnormalities in Purkinje cell biology in essential tremor, we hypothesized that regressive changes in dendritic morphology would be apparent in the Purkinje cell population in essential tremor cases versus age-matched controls. Cerebellar cortical tissue from 27 cases with essential tremor and 27 age-matched control subjects was processed by the Golgi-Kopsch method. Purkinje cell dendritic anatomy was quantified using a Neurolucida microscopic system interfaced with a motorized stage. In all measures, essential tremor cases demonstrated significant reductions in dendritic complexity compared with controls. Median values in essential tremor cases versus controls were: 5712.1 versus 10 403.2 µm (total dendrite length, P=0.01), 465.9 versus 592.5 µm (branch length, P=0.01), 22.5 versus 29.0 (maximum branch order, P=0.001), and 165.3 versus 311.7 (number of terminations, P=0.008). Furthermore, the dendritic spine density was reduced in essential tremor cases (medians=0.82 versus 1.02 µm(-1), P=0.03). Our demonstration of regressive changes in Purkinje cell dendritic architecture and spines in essential tremor relative to control brains provides additional evidence of a pervasive abnormality of Purkinje cell biology in this disease, which affects multiple neuronal cellular compartments including their axon, cell body, dendrites and spines.

  12. Successful Isothermal Dendritic Growth Experiment (IDGE) Proves Current Theories of Dendritic Solidification are Flawed

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The scientific objective of the Isothermal Dendritic Growth Experiment (IDGE) is to test fundamental assumptions about dendritic solidification of molten materials. "Dendrites"-- from the ancient Greek word for tree--are tiny branching structures that form inside molten metal alloys when they solidify during manufacturing. The size, shape, and orientation of the dendrites have a major effect on the strength, ductility (ability to be molded or shaped), and usefulness of an alloy. Nearly all of the cast metal alloys used in everyday products (such as automobiles and airplanes) are composed of thousands to millions of tiny dendrites. Gravity, present on Earth, causes convection currents in molten alloys that disturb dendritic solidification and make its precise study impossible. In space, gravity is negated by the orbiting of the space shuttle. Consequently, IDGE (which was conducted on the space shuttle) gathered the first precise data regarding undisturbed dendritic solidification. IDGE is a microgravity materials science experiment that uses an apparatus which was designed, built, tested, and operated by people from the NASA Lewis Research Center. This experiment was conceived by the principal investigator, Professor Martin E. Glicksman, from Rensselaer Polytechnic Institute in Troy, New York. The experiment was a team effort of Lewis civil servants, contractors from Aerospace Design & Fabrication Inc. (ADF), and personnel at Rensselaer.

  13. Inductive Reasoning and Writing

    ERIC Educational Resources Information Center

    Rooks, Clay; Boyd, Robert

    2003-01-01

    Induction, properly understood, is not merely a game, nor is it a gimmick, nor is it an artificial way of explaining an element of reasoning. Proper understanding of inductive reasoning--and the various types of reasoning that the authors term inductive--enables the student to evaluate critically other people's writing and enhances the composition…

  14. Teaching Arrangement Inductively.

    ERIC Educational Resources Information Center

    Mendelson, Michael

    1988-01-01

    Argues that teaching arrangement inductively offers an alternative to the standard imitation of business communication text models. Asserts that the inductive method stimulates individual rather than formulaic responses to the problems of organization, and that inductively-trained writers see arrangements as a powerful element in persuasive…

  15. The path integral for dendritic trees.

    PubMed

    Abbott, L F; Farhi, E; Gutmann, S

    1991-01-01

    We construct the path integral for determining the potential on any dendritic tree described by a linear cable equation. This is done by generalizing Brownian motion from a line to a tree. We also construct the path integral for dendritic structures with spatially-varying and/or time-dependent membrane conductivities due, for example, to synaptic inputs. The path integral allows novel computational techniques to be applied to cable problems. Our analysis leads ultimately to an exact expression for the Green's function on a dendritic tree of arbitrary geometry expressed in terms of a set of simple diagrammatic rules. These rules providing a fast and efficient method for solving complex cable problems.

  16. Dendritic inhomogeneity of stainless maraging steels

    SciTech Connect

    Krasnikova, S.I.; Drobot, A.V.; Shmelev, A.Y.; Vukelich, S.B.

    1986-03-01

    The authors investigated dendritic inhomogeneity in industrial ingots 630 mm (steel I) in diameter and 500 mm (steel II) in diameter. The variation in the degree of dendritic inhomogeneity was investigated over the height of the ingots and across the sections on an MS-46 microprobe. It was established that the elements can be placed in the following order in accordance with the degree of reduction in the liquation factor: titanium, molybdenum, nickel, chromium, and cobalt. Titanium and molybdenum exhibit forward liquation in both steels, and chromium in steel II. The distribution of nickel and chromium in the steel I ingots and cobalt in the steel II ingots is unconventional. Dendritic inhomogeneity, which must be considered in assigning the heat treatment for finished articles, develops during the crystallization of stainless maraging steels.

  17. Measuring dendritic distribution of membrane proteins.

    PubMed

    Ballou, Edmund W; Smith, W Bryan; Anelli, Roberta; Heckman, C J

    2006-09-30

    Neurons perform much of their integrative work in the dendritic tree, and spinal motoneurons have the largest tree of any cell. Electrical excitability is strongly influenced by dendrite membrane properties, which are difficult to measure directly. We describe a method to measure the distribution of ion channel membrane densities along dendritic trajectories. The method combines standard immunohistochemistry with reconstruction procedures for both large-scale and small-scale optical microscopy. Software written for Matlab then extracts the colocalization of the target ion channel with the target dye injected cell, and calculates the relative channel density per square micron of cell surface area, as a function of distance from the cell body. The technique can be used to quantify the localization and distribution of any immunoreactive moiety, and the software provides a flexible vehicle for sensitivity analysis, to validate heuristics for selecting thresholds.

  18. Local administration of granulocyte macrophage colony-stimulating factor induces local accumulation of dendritic cells and antigen-specific CD8+ T cells and enhances dendritic cell cross-presentation.

    PubMed

    Lee, Sung-Jong; Song, Liwen; Yang, Ming-Chieh; Mao, Chih-Ping; Yang, Benjamin; Yang, Andrew; Jeang, Jessica; Peng, Shiwen; Wu, T-C; Hung, Chien-Fu

    2015-03-24

    Immunotherapy has emerged as a promising treatment strategy for the control of HPV-associated malignancies. Various therapeutic HPV vaccines have elicited potent antigen-specific CD8+ T cell mediated antitumor immune responses in preclinical models and are currently being tested in several clinical trials. Recent evidence indicates the importance of local immune activation, and higher number of immune cells in the site of lesion correlates with positive prognosis. Granulocyte macrophage colony-stimulating factor (GMCSF) has been reported to posses the ability to induce migration of antigen presentation cells and CD8+ T cells. Therefore, in the current study, we employ a combination of systemic therapeutic HPV DNA vaccination with local GMCSF application in the TC-1 tumor model. We show that intramuscular vaccination with CRT/E7 DNA followed by GMCSF intravaginal administration effectively controls cervicovaginal TC-1 tumors in mice. Furthermore, we observe an increase in the accumulation of E7-specific CD8+ T cells and dendritic cells in vaginal tumors following the combination treatment. In addition, we show that GMCSF induces activation and maturation in dendritic cells and promotes antigen cross-presentation. Our results support the clinical translation of the combination treatment of systemic therapeutic vaccination followed by local GMCSF administration as an effective strategy for tumor treatment.

  19. Convection Effects in Three-dimensional Dendritic Growth

    NASA Technical Reports Server (NTRS)

    Lu, Yili; Beckermann, C.; Karma, A.

    2003-01-01

    A phase-field model is developed to simulate free dendritic growth coupled with fluid flow for a pure material in three dimensions. The preliminary results presented here illustrate the strong influence of convection on the three-dimensional (3D) dendrite growth morphology. The detailed knowledge of the flow and temperature fields in the melt around the dendrite from the simulations allows for a detailed understanding of the convection effects on dendritic growth.

  20. Role and therapeutic value of dendritic cells in central nervous system autoimmunity

    PubMed Central

    Quintana, F J; Yeste, A; Mascanfroni, I D

    2015-01-01

    Dendritic cells (DCs) are professional antigen-presenting cells that control the generation of adaptive immunity. Consequently, DCs have a central role in the induction of protective immunity to pathogens and also in the pathogenic immune response responsible for the development and progression of autoimmune disorders. Thus the study of the molecular pathways that control DC development and function is likely to result in new strategies for the therapeutic manipulation of the immune response. In this review, we discuss the role and therapeutic value of DCs in autoimmune diseases, with a special focus on multiple sclerosis. PMID:25168240

  1. Dendritic cell targeting vaccine for HPV-associated cancer

    PubMed Central

    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

  2. Regulation of dendrite growth and maintenance by exocytosis.

    PubMed

    Peng, Yun; Lee, Jiae; Rowland, Kimberly; Wen, Yuhui; Hua, Hope; Carlson, Nicole; Lavania, Shweta; Parrish, Jay Z; Kim, Michael D

    2015-12-01

    Dendrites lengthen by several orders of magnitude during neuronal development, but how membrane is allocated in dendrites to facilitate this growth remains unclear. Here, we report that Ras opposite (Rop), the Drosophila ortholog of the key exocytosis regulator Munc18-1 (also known as STXBP1), is an essential factor mediating dendrite growth. Neurons with depleted Rop function exhibit reduced terminal dendrite outgrowth followed by primary dendrite degeneration, suggestive of differential requirements for exocytosis in the growth and maintenance of different dendritic compartments. Rop promotes dendrite growth together with the exocyst, an octameric protein complex involved in tethering vesicles to the plasma membrane, with Rop-exocyst complexes and exocytosis predominating in primary dendrites over terminal dendrites. By contrast, membrane-associated proteins readily diffuse from primary dendrites into terminals, but not in the reverse direction, suggesting that diffusion, rather than targeted exocytosis, supplies membranous material for terminal dendritic growth, revealing key differences in the distribution of materials to these expanding dendritic compartments.

  3. Silicon dendritic web growth thermal analysis task

    NASA Technical Reports Server (NTRS)

    Richter, R.; Bhandari, P.

    1985-01-01

    A thermal analysis model is presented which describes the dendritic ribbon process. The model uses a melt-dendrite interface which projects out of the bulk melt as the basic interpretation of the ribbon production process. This is a marked departure from the interpretations of the interface phenomena which were used previously. The model was extensively illustrated with diagrams and pictures of ribbon samples. This model should have great impact on the analyses of experimental data as well as on future design modifications of ribbon-pulling equipment.

  4. Apparatus for growing a dendritic web

    DOEpatents

    Duncan, Charles S.; Piotrowski, Paul A.; Skutch, Maria E.; McHugh, James P.

    1983-06-21

    A melt system including a susceptor-crucible assembly having improved gradient control when melt replenishment is used during dendritic web growth. The improvement lies in the formation of a thermal barrier in the base of the receptor which is in the form of a vertical slot in the region of the susceptor underlying the crucible at the location of a compartmental separator dividing the crucible into a growth compartment and a melt replenishment compartment. The result achieved is a step change in temperature gradient in the melt thereby providing a more uniform temperature in the growth compartment from which the dendritic web is drawn.

  5. The Isothermal Dendritic Growth Experiment (IDGE)

    NASA Technical Reports Server (NTRS)

    Glicksman, Martin E.; Koss, M. B.; Lupulescu, A. O.; LaCombe, J. C.; Frei, J. E.; Malarik, D. C.

    1999-01-01

    The Isothermal Dendritic Growth Experiment (IDGE) constituted a series of three NASA-supported microgravity experiments, all of which flew aboard the space shuttle, Columbia. This experimental space flight series was designed and operated to grow and record dendrite solidification in the absence of gravity-induced convective heat transfer, and thereby produce a wealth of benchmark-quality data for testing solidification scaling laws. The data and analysis performed on the dendritic growth speed and tip size in Succinontrie (SCN) demonstrates that although the theory yields predictions that are reasonably in agreement with experiment, there are significant discrepancies. However, some of these discrepancies can be explained by accurately describing the diffusion of heat. The key finding involves recognition that the actual three-dimensional shape of dendrites includes time-dependent side-branching and a tip region that is not a paraboloid of revolution. Thus, the role of heat transfer in dendritic growth is validated, with the caveat that a more realistic model of the dendrite then a paraboloid is needed to account for heat flow in an experimentally observed dendrite. We are currently conducting additional analysis to further confirm and demonstrate these conclusions. The data and analyses for the growth selection physics remain much less definitive. From the first flight, the data indicated that the selection parameter, sigma*, is not exactly a constant, but exhibits a slight dependence on the supercooling. Additional data from the second flight are being examined to investigate the selection of a unique dendrite speed, tip size and shape. The IDGE flight series is now complete. We are currently completing analyses and moving towards final data archiving. It is gratifying to see that the IDGE published results and archived data sets are being used actively by other scientists and engineers. In addition, we are also pleased to report that the techniques and IDGE

  6. The multifaceted biology of plasmacytoid dendritic cells

    PubMed Central

    Swiecki, Melissa; Colonna, Marco

    2015-01-01

    Plasmacytoid dendritic cells (pDCs) are a unique dendritic cell subset that specializes in the production of type I interferons (IFNs). pDCs promote antiviral immune responses and have been implicated in the pathogenesis of autoimmune diseases characterized by a type I IFN signature. However, pDCs can also induce tolerogenic immune responses. Here, we review recent progress from the field of pDC biology, focusing on: the molecular mechanisms that regulate pDC development and functions; the pathways involved in their sensing of pathogens and endogenous nucleic acids; the function of pDCs at mucosal sites; and their roles in infections, autoimmunity and cancer. PMID:26160613

  7. On dendritic growth in undercooled melts

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.

    1988-01-01

    The role of gravity-dependent convection in the steady-state growth of dendrites in undercooled melts is investigated theoretically. The model described by Huang and Glicksman (1981) is extended and refined, using the concept of a thermal diffusion boundary layer (Burton et al., 1987) to characterize the dendritic interface. Theoretical predictions are presented in graphs and shown to be in good general agreement with published experimental data on succinonitrile. The need for careful space experiments to clarify the role of nongravity-dependent convection is indicated.

  8. Epileptiform activity induces distance-dependent alterations of the Ca2+ extrusion mechanism in the apical dendrites of subicular pyramidal neurons.

    PubMed

    Srinivas, Kalyan V; Sikdar, Sujit K

    2008-12-01

    The cellular and molecular mechanisms that underlie acquired changes in Ca(2+) dynamics of different neuronal compartments are important in the induction and maintenance of epileptiform activity. Simultaneous electrophysiology and Ca(2+) imaging techniques were used to understand the basic properties of dendritic Ca(2+) signaling in rat subicular pyramidal neurons during epileptiform activity. Distance-dependent changes in the Ca(2+) decay kinetics locked to spontaneous epileptiform discharges and back-propagating action potentials were observed in the apical dendrites. A decrement in the mean tau value of Ca(2+) decay was observed in distal parts (95-110 mum) of the apical dendrites compared with proximal segments (30-45 mum) in in-vitro epileptic conditions but not in control. Pharmacological agents that block Ca(2+) transporters, i.e. Na(+)/ Ca(2+) exchangers (Benzamil), plasma membrane Ca(2+)-ATPase pumps (Calmidazolium) and smooth endoplasmic reticulum Ca(2+)-ATPase pumps (Thapsigargin), were applied locally to the proximal and distal part of the apical dendrites in both experimental conditions to understand the molecular aspects of the Ca(2+) extrusion mechanisms. The relative contribution of Na(+)/Ca(2+) exchangers in Ca(2+) extrusion was higher in the distal apical dendrites in the in-vitro epileptic condition and this property modulated the excitability of the neuron in simulation. The Ca(2+) homeostatic mechanisms that restore normal Ca(2+) levels could play a major neuroprotective role in the distal dendrites that receive synaptic inputs.

  9. Cell-mediated immunity to insulin: a new criterion for differentiation of diabetes mellitus?

    PubMed

    Asfandiyarova, Nailya S

    2012-03-01

    Any classification is a step forward and it should help to determine the reason, the course, the prognosis, the treatment of a disease. The current classification of diabetes mellitus (DM) is really very convenient for work, but it has some drawbacks, and the absence of differentiation of type 2 diabetes is the main. The problem is the absence of an adequate criterion, based on pathogenesis for differentiation. We suppose that cell mediated immunity (CMI) to insulin plays the central role in the diabetes genesis. Autoimmune process may be triggered by viruses family Paramyxoviridae, in 10-20% of type 1 diabetes patients the disease is a consequence of direct cytotoxic effect of other viruses to the islet cells of pancreas. In acute phase of viral infection (measles, mumps, parainfluenza) CMI against viruses is developed, in some patients CMI to insulin appeared. We suppose that autoimmune reactions in these cases are the result of cross reaction between viral antigens and insulin. The majorities of patients suppress these reactions and recover from acute infection diseases with the antiviral immunity development and without any complications. Other patients are not able to suppress autoimmune reactions to insulin and pathological process is triggered. Type 1A diabetes is a result of direct CMI to insulin, and this process is responsible for beta-cells destruction; may be type 1B DM is due to the direct cytotoxic effect of other viruses or toxins to them. Some patients with acute viral infection cannot destroy the aggressive clone and they suppress autoimmune reaction to insulin by prostaglandin synthesizing cells (PGSC) or сells with histamine receptors (CHR). As a result of this process the insulin resistance is developed, because these cells or their cytokines form a block to the insulin receptors not only on immunocompetent cells, but in insulin sensitive tissues too. Patients with different reactions to insulin have different courses and outcomes of DM. We

  10. Cell mediated therapeutics for cancer treatment: Tumor homing cells as therapeutic delivery vehicles

    NASA Astrophysics Data System (ADS)

    Balivada, Sivasai

    Many cell types were known to have migratory properties towards tumors and different research groups have shown reliable results regarding cells as delivery vehicles of therapeutics for targeted cancer treatment. Present report discusses proof of concept for 1. Cell mediated delivery of Magnetic nanoparticles (MNPs) and targeted Magnetic hyperthermia (MHT) as a cancer treatment by using in vivo mouse cancer models, 2. Cells surface engineering with chimeric proteins for targeted cancer treatment by using in vitro models. 1. Tumor homing cells can carry MNPs specifically to the tumor site and tumor burden will decrease after alternating magnetic field (AMF) exposure. To test this hypothesis, first we loaded Fe/Fe3O4 bi-magnetic NPs into neural progenitor cells (NPCs), which were previously shown to migrate towards melanoma tumors. We observed that NPCs loaded with MNPs travel to subcutaneous melanoma tumors. After alternating magnetic field (AMF) exposure, the targeted delivery of MNPs by the NPCs resulted in a mild decrease in tumor size (Chapter-2). Monocytes/macrophages (Mo/Ma) are known to infiltrate tumor sites, and also have phagocytic activity which can increase their uptake of MNPs. To test Mo/Ma-mediated MHT we transplanted Mo/Ma loaded with MNPs into a mouse model of pancreatic peritoneal carcinomatosis. We observed that MNP-loaded Mo/Ma infiltrated pancreatic tumors and, after AMF treatment, significantly prolonged the lives of mice bearing disseminated intraperitoneal pancreatic tumors (Chapter-3). 2. Targeted cancer treatment could be achieved by engineering tumor homing cell surfaces with tumor proteases cleavable, cancer cell specific recombinant therapeutic proteins. To test this, Urokinase and Calpain (tumor specific proteases) cleavable; prostate cancer cell (CaP) specific (CaP1 targeting peptide); apoptosis inducible (Caspase3 V266ED3)- rCasp3V266ED3 chimeric protein was designed in silico. Hypothesized membrane anchored chimeric protein (rCasp3V

  11. Gamma Delta T Cells Mediate Angiotensin II-Induced Hypertension and Vascular Injury.

    PubMed

    Caillon, Antoine; Mian, Muhammad Oneeb Rehman; Fraulob-Aquino, Julio C; Huo, Ku-Geng; Barhoumi, Tlili; Ouerd, Sofiane; Sinnaeve, Peter R; Paradis, Pierre; Schiffrin, Ernesto L

    2017-03-22

    multiple linear regression model integrating whole blood TCR γ constant region gene expression levels, and age and sex (R(2)=0.12, P<1x10(-6)). Conclusions -γδ T cells mediate Ang II-induced SBP elevation, vascular injury and T-cell activation in mice. γδ T cells might contribute to development of hypertension in humans.

  12. Heterogeneity of human lymphocyte Fc receptors. II. Relationship to antibody-dependent, cell-mediated cytotoxicity

    PubMed Central

    Gormus, B. J.; Woodson, Mildred; Kaplan, M. E.

    1978-01-01

    Human peripheral blood lymphocytes (PBL) were incubated (stripped) with pronase or papain and compared with unstripped lymphocytes for their ability to mediate antibody-dependent, cell-mediated cytotoxicity (ADCC). Despite marked removal or inactivation of receptors for heat-aggregated IgG (aggG) by proteolytic digestion, and pronounced changes in the percentages of cells rosetting with IgG-sensitized erythrocytes (EA) (decreased by papain, increased by pronase), stripped PBL functioned normally in ADCC. Stripped and unstripped lymphocytes were pre-treated with aggG to determine the role of aggG receptors in ADCC. AggG almost totally abolished ADCC by unstripped PBL, but inhibited ADCC by enzyme-stripped lymphocytes relatively poorly. Neither untreated nor stripped PBL were able to induce cytotoxicity of chicken erythrocyte (CRBC) target cells sensitized with the Fab'2 fragment of anti-CRBC IgG antibody (CRBC-A). Exposure of PBL to EA monolayers composed of CRBC-A or of sheep erythrocytes (SRBC) sensitized with rabbit anti-SRBC IgG antibody (SRBC-A) depleted PBL of cells that rosetted with CRBC-A and with human Rh-positive, type O erythrocytes sensitized with the human anti-Rh serum Ripley (HRBC-A Ripley). Non-adherent cells were incapable of binding aggG and had markedly diminished cytotoxicity in ADCC. Similarly, exposure of PBL to HRBC-A Ripley monolayers resulted in non-adherent cells that were incapable of rosette formation with HRBC-A or CRBC-A, failed to bind aggG, and exhibited significantly diminished ADCC activity. These studies indicated that: (1) cytotoxic effector PBL active in ADCC (K cells) have receptors for aggG and for EA; (2) PBL deficient in functional aggG receptors (enzymatically inactivated or removed) are capable of inducing normal levels of ADCC; (3) aggG and EA receptors appear to be closely associated on native K-cell membranes; (4) there is no clear-cut relationship in a given lymphocyte population between the presence of either aggG or

  13. Heterogeneous effects of exogenous IL-2 on HIV-specific cell-mediated immunity (CMI).

    PubMed Central

    Bell, S J; Cooper, D A; Kemp, B E; Doherty, R R; Penny, R

    1992-01-01

    A characteristic feature associated with HIV-1 infection of the human host is a chronic decline in circulating CD4+ T helper/inducer cell numbers. Impaired cell-mediated immune functions usually occur in parallel with the decline in CD4+ T cells. Activated CD4+ T helper cells are a major source of endogenous IL-2 which is required for the immunoregulation of both antigen-specific B cells and CD8+ T cells. HIV-specific T cell proliferative responses are said to be weak and inconsistent, even during the asymptomatic phase of disease. We thus wished to determine how exogenous IL-2 affected HIV-specific T cell proliferation at different stages of the disease. Our cohort of 81 included both asymptomatic and symptomatic HIV-infected patients as well as uninfected normal donors. Proliferative responses of peripheral blood mononuclear cells (PBMC) that were elicited during culture with an immunodominant gp41-derived synthetic peptide, gp41[8], and which were known to be CD8+ cell-associated in asymptomatics only, were used to analyse the effects of exogenous IL-2. IL-2 had three main effects on HIV-specific proliferation, namely (i) an additive effect, (ii) a synergistic effect, and (iii) an induced effect. More specifically, low dose exogenous IL-2 frequently augmented lymphoproliferation in both asymptomatic and symptomatic gp41[8] responders. In most symptomatics, however, who were predominantly gp41[8] non-responders, exogenous IL-2 induced lymphoproliferation. Flow cytometric analyses using dual immunofluorescence were used to analyse the T cell subset distribution of proliferating PBMC cultures. During culture with gp41[8], both CD4+ and CD8+ T cell numbers increased. However, after the addition of exogenous IL-2 to gp41[8]-containing cultures, CD8+ cell-associated lymphoproliferative responses were preferentially augmented. These results suggest that in symptomatics there is an inadequate supply of endogenous IL-2 to help maintain the strong and effective CD8+ cell

  14. Pulsed IR inductive lasers

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Churkin, D. S.; Kargapol'tsev, E. S.

    2014-07-01

    Pulsed inductive discharge is a new alternative method of pumping active gas laser media. The work presents results of experimental investigations of near, mid, and far IR inductive gas lasers (H2, HF, and CO2) operating at different transitions of atoms and molecules with different mechanisms of formation of inversion population. The excitation systems of a pulsed inductive cylindrical discharge (pulsed inductively coupled plasma) and pulsed RF inductive discharge in the gases are developed. Various gas mixtures including H2, N2, He, Ne, F2, NF3, and SF6 are used. Characteristics of near IR H2 laser radiation are investigated. Maximal pulse peak power of 7 kW is achieved. The possibility of using a pulsed inductive discharge as a new method of pumping HF laser active medium is demonstrated. The pulsed RF inductive CO2 laser is created and a total efficiency of 17% is achieved.

  15. Chimeric Vaccine Stimulation of Human Dendritic Cell Indoleamine 2, 3-Dioxygenase Occurs via the Non-Canonical NF-κB Pathway.

    PubMed

    Kim, Nan-Sun; Mbongue, Jacques C; Nicholas, Dequina A; Esebanmen, Grace E; Unternaehrer, Juli J; Firek, Anthony F; Langridge, William H R

    2016-01-01

    A chimeric protein vaccine composed of the cholera toxin B subunit fused to proinsulin (CTB-INS) was shown to suppress type 1 diabetes onset in NOD mice and upregulate biosynthesis of the tryptophan catabolic enzyme indoleamine 2, 3-dioxygenase (IDO1) in human dendritic cells (DCs). Here we demonstrate siRNA inhibition of the NF-κB-inducing kinase (NIK) suppresses vaccine-induced IDO1 biosynthesis as well as IKKα phosphorylation. Chromatin immunoprecipitation (ChIP) analysis of CTB-INS inoculated DCs showed that RelB bound to NF-κB consensus sequences in the IDO1 promoter, suggesting vaccine stimulation of the non-canonical NF-κB pathway activates IDO1 expression in vivo. The addition of Tumor Necrosis Factor Associated Factors (TRAF) TRAF 2, 3 and TRAF6 blocking peptides to vaccine inoculated DCs was shown to inhibit IDO1 biosynthesis. This experimental outcome suggests vaccine activation of the TNFR super-family receptor pathway leads to upregulation of IDO1 biosynthesis in CTB-INS inoculated dendritic cells. Together, our experimental data suggest the CTB-INS vaccine uses a TNFR-dependent signaling pathway of the non-canonical NF-κB signaling pathway resulting in suppression of dendritic cell mediated type 1 diabetes autoimmunity.

  16. Interactions with Astroglia Influence the Shape of the Developing Dendritic Arbor and Restrict Dendrite Growth Independent of Promoting Synaptic Contacts.

    PubMed

    Withers, Ginger S; Farley, Jennifer R; Sterritt, Jeffrey R; Crane, Andrés B; Wallace, Christopher S

    2017-01-01

    Astroglia play key roles in the development of neurons, ranging from regulating neuron survival to promoting synapse formation, yet basic questions remain about whether astrocytes might be involved in forming the dendritic arbor. Here, we used cultured hippocampal neurons as a simple in vitro model that allowed dendritic growth and geometry to be analyzed quantitatively under conditions where the extent of interactions between neurons and astrocytes varied. When astroglia were proximal to neurons, dendrites and dendritic filopodia oriented toward them, but the general presence of astroglia significantly reduced overall dendrite growth. Further, dendritic arbors in partial physical contact with astroglia developed a pronounced pattern of asymmetrical growth, because the dendrites in direct contact were significantly smaller than the portion of the arbor not in contact. Notably, thrombospondin, the astroglial factor shown previously to promote synapse formation, did not inhibit dendritic growth. Thus, while astroglia promoted the formation of presynaptic contacts onto dendrites, dendritic growth was constrained locally within a developing arbor at sites where dendrites contacted astroglia. Taken together, these observations reveal influences on spatial orientation of growth as well as influences on morphogenesis of the dendritic arbor that have not been previously identified.

  17. Interactions with Astroglia Influence the Shape of the Developing Dendritic Arbor and Restrict Dendrite Growth Independent of Promoting Synaptic Contacts

    PubMed Central

    Farley, Jennifer R.; Sterritt, Jeffrey R.; Crane, Andrés B.; Wallace, Christopher S.

    2017-01-01

    Astroglia play key roles in the development of neurons, ranging from regulating neuron survival to promoting synapse formation, yet basic questions remain about whether astrocytes might be involved in forming the dendritic arbor. Here, we used cultured hippocampal neurons as a simple in vitro model that allowed dendritic growth and geometry to be analyzed quantitatively under conditions where the extent of interactions between neurons and astrocytes varied. When astroglia were proximal to neurons, dendrites and dendritic filopodia oriented toward them, but the general presence of astroglia significantly reduced overall dendrite growth. Further, dendritic arbors in partial physical contact with astroglia developed a pronounced pattern of asymmetrical growth, because the dendrites in direct contact were significantly smaller than the portion of the arbor not in contact. Notably, thrombospondin, the astroglial factor shown previously to promote synapse formation, did not inhibit dendritic growth. Thus, while astroglia promoted the formation of presynaptic contacts onto dendrites, dendritic growth was constrained locally within a developing arbor at sites where dendrites contacted astroglia. Taken together, these observations reveal influences on spatial orientation of growth as well as influences on morphogenesis of the dendritic arbor that have not been previously identified. PMID:28081563

  18. Synaptic activation of ribosomal protein S6 phosphorylation occurs locally in activated dendritic domains.

    PubMed

    Pirbhoy, Patricia Salgado; Farris, Shannon; Steward, Oswald

    2016-06-01

    Previous studies have shown that induction of long-term potentiation (LTP) induces phosphorylation of ribosomal protein S6 (rpS6) in postsynaptic neurons, but the functional significance of rpS6 phosphorylation is poorly understood. Here, we show that synaptic stimulation that induces perforant path LTP triggers phosphorylation of rpS6 (p-rpS6) locally near active synapses. Using antibodies specific for phosphorylation at different sites (ser235/236 versus ser240/244), we show that strong synaptic activation led to dramatic increases in immunostaining throughout postsynaptic neurons with selectively higher staining for p-ser235/236 in the activated dendritic lamina. Following LTP induction, phosphorylation at ser235/236 was detectable by 5 min, peaked at 30 min, and was maintained for hours. Phosphorylation at both sites was completely blocked by local infusion of the NMDA receptor antagonist, APV. Despite robust induction of p-rpS6 following high frequency stimulation, assessment of protein synthesis by autoradiography revealed no detectable increases. Exploration of a novel environment led to increases in the number of p-rpS6-positive neurons throughout the forebrain in a pattern reminiscent of immediate early gene induction and many individual neurons that were p-rpS6-positive coexpressed Arc protein. Our results constrain hypotheses about the possible role of rpS6 phosphorylation in regulating postsynaptic protein synthesis during induction of synaptic plasticity.

  19. Antibody-Dependent Cell-Mediated Cytotoxicity Epitopes on the Hemagglutinin Head Region of Pandemic H1N1 Influenza Virus Play Detrimental Roles in H1N1-Infected Mice

    PubMed Central

    Ye, Zi-Wei; Yuan, Shuofeng; Poon, Kwok-Man; Wen, Lei; Yang, Dong; Sun, Zehua; Li, Cun; Hu, Meng; Shuai, Huiping; Zhou, Jie; Zhang, Mei-Yun; Zheng, Bo-Jian; Chu, Hin; Yuen, Kwok-Yung

    2017-01-01

    Engaging the antibody-dependent cell-mediated cytotoxicity (ADCC) for killing of virus-infected cells and secretion of antiviral cytokines and chemokines was incorporated as one of the important features in the design of universal influenza vaccines. However, investigation of the ADCC epitopes on the highly immunogenic influenza hemagglutinin (HA) head region has been rarely reported. In this study, we determined the ADCC and antiviral activities of two putative ADCC epitopes, designated E1 and E2, on the HA head of a pandemic H1N1 influenza virus in vitro and in a lethal mouse model. Our data demonstrated that sera from the E1-vaccinated mice could induce high ADCC activities. Importantly, the induction of ADCC response modestly decreased viral load in the lungs of H1N1-infected mice. However, the elevated ADCC significantly increased mouse alveolar damage and mortality than that of the PBS-vaccinated group (P < 0.0001). The phenotype was potentially due to an exaggerated inflammatory cell infiltration triggered by ADCC, as an upregulated release of cytotoxic granules (perforin) was observed in the lung tissue of E1-vaccinated mice after H1N1 influenza virus challenge. Overall, our data suggested that ADCC elicited by certain domains of HA head region might have a detrimental rather than protective effect during influenza virus infection. Thus, future design of universal influenza vaccine shall strike a balance between the induction of protective immunity and potential side effects of ADCC. PMID:28377769

  20. Abl2/Arg controls dendritic spine and dendrite arbor stability via distinct cytoskeletal control pathways.

    PubMed

    Lin, Yu-Chih; Yeckel, Mark F; Koleske, Anthony J

    2013-01-30

    Rho family GTPases coordinate cytoskeletal rearrangements in neurons, and mutations in their regulators are associated with mental retardation and other neurodevelopmental disorders (Billuart et al., 1998; Kutsche et al., 2000; Newey et al., 2005; Benarroch, 2007). Chromosomal microdeletions encompassing p190RhoGAP or its upstream regulator, the Abl2/Arg tyrosine kinase, have been observed in cases of mental retardation associated with developmental defects (Scarbrough et al., 1988; James et al., 1996; Takano et al., 1997; Chaabouni et al., 2006; Leal et al., 2009). Genetic knock-out of Arg in mice leads to synapse, dendritic spine, and dendrite arbor loss accompanied by behavioral deficits (Moresco et al., 2005; Sfakianos et al., 2007). To elucidate the cell-autonomous mechanisms by which Arg regulates neuronal stability, we knocked down Arg in mouse hippocampal neuronal cultures. We find that Arg knockdown significantly destabilizes dendrite arbors and reduces dendritic spine density by compromising dendritic spine stability. Inhibiting RhoA prevents dendrite arbor loss following Arg knockdown in neurons, but does not block spine loss. Interestingly, Arg-deficient neurons exhibit increased miniature EPSC amplitudes, and their remaining spines exhibit larger heads deficient in the actin stabilizing protein cortactin. Spine destabilization in Arg knockdown neurons is prevented by blocking NMDA receptor-dependent relocalization of cortactin from spines, or by forcing cortactin into spines via fusion to an actin-binding region of Arg. Thus, Arg employs distinct mechanisms to selectively regulate spine and dendrite stability: Arg dampens activity-dependent disruption of cortactin localization to stabilize spines and attenuates Rho activity to stabilize dendrite arbors.

  1. ISOLATION OF CHICKEN FOLLICULAR DENDRITIC CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Hyper-dendritic nanoporous zinc foam anodes

    DOE PAGES

    Chamoun, Mylad; Hertzberg, Benjamin J.; Gupta, Tanya; ...

    2015-04-24

    The low cost, significant reducing potential, and relative safety of the zinc electrode is a common hope for a reductant in secondary batteries, but it is limited mainly to primary implementation due to shape change. In this work we exploit such shape change for the benefit of static electrodes through the electrodeposition of hyper-dendritic nanoporous zinc foam. Electrodeposition of zinc foam resulted in nanoparticles formed on secondary dendrites in a three-dimensional network with a particle size distribution of 54.1 - 96.0 nm. The nanoporous zinc foam contributed to highly oriented crystals, high surface area and more rapid kinetics in contrastmore » to conventional zinc in alkaline mediums. The anode material presented had a utilization of ~ 88% at full depth-of-discharge at various rates indicating a superb rate-capability. The rechargeability of Zn⁰/Zn²⁺ showed significant capacity retention over 100 cycles at a 40% depth-of-discharge to ensure that the dendritic core structure was imperforated. The dendritic architecture was densified upon charge-discharge cycling and presented superior performance compared to bulk zinc electrodes.« less

  3. Hyper-dendritic nanoporous zinc foam anodes

    SciTech Connect

    Chamoun, Mylad; Hertzberg, Benjamin J.; Gupta, Tanya; Davies, Daniel; Bhadra, Shoham; Van Tassell, Barry.; Erdonmez, Can; Steingart, Daniel A.

    2015-04-24

    The low cost, significant reducing potential, and relative safety of the zinc electrode is a common hope for a reductant in secondary batteries, but it is limited mainly to primary implementation due to shape change. In this work we exploit such shape change for the benefit of static electrodes through the electrodeposition of hyper-dendritic nanoporous zinc foam. Electrodeposition of zinc foam resulted in nanoparticles formed on secondary dendrites in a three-dimensional network with a particle size distribution of 54.1 - 96.0 nm. The nanoporous zinc foam contributed to highly oriented crystals, high surface area and more rapid kinetics in contrast to conventional zinc in alkaline mediums. The anode material presented had a utilization of ~ 88% at full depth-of-discharge at various rates indicating a superb rate-capability. The rechargeability of Zn⁰/Zn²⁺ showed significant capacity retention over 100 cycles at a 40% depth-of-discharge to ensure that the dendritic core structure was imperforated. The dendritic architecture was densified upon charge-discharge cycling and presented superior performance compared to bulk zinc electrodes.

  4. Defect characterization of silicon dendritic web ribbons

    NASA Technical Reports Server (NTRS)

    Cheng, L. J.

    1985-01-01

    Progress made in the study of defect characterization of silicon dendritic web ribbon is presented. Chemical etching is used combined with optical microscopy, as well as the electron beam induced current (EBIC) technique. Thermal annealing effect on carrier lifetime is examined.

  5. Dendritic growth in a supercooled alloy melt

    NASA Technical Reports Server (NTRS)

    Laxmanan, V.

    1987-01-01

    A simple model which describes the growth of an 'array' of dendrites into a supercooled, binary, alloy melt is presented. Solute diffusion is calculated by superposing the solutions given by Flemings and Zener, and also, by superposing the solutions given by Ivantsov and Flemings. A general expression for the transport solution is suggested from which all other dendrite growth models presented earlier may be obtained as special cases. It is shown that both 'free' and 'constrained' growth may be described by a single transport solution, which indicates that (1) both thermal and solutal effects will be important during 'free' growth in dilute alloys, (2) only solutal effects are predominant during 'free' growth in concentrated alloys and during 'constrained' growth. An examination of the relevant dimensionless parameters also suggests that all dendrite growth models, regardless of the assumptions used to determine the tip radius (marginal stability, minimum undercooling, maximum velocity, minimum entropy production) should predict the experimentally observed extrema in tip radius and growth velocity in dilute alloys, during 'free' dendritic growth. Experimental data in binary H2O-NaCl and succinonitrile-acetone solutions are shown to be in good agreement with the model.

  6. Immune activation: death, danger and dendritic cells.

    PubMed

    Pulendran, Bali

    2004-01-06

    Dendritic cells are critical for host immunity, and sense microbes with pathogen recognition receptors. New evidence indicates that these cells also sense uric acid crystals in dead cells, suggesting that the immune system is conscious not only of pathogens, but also of death and danger.

  7. Dendritic Cells, New Tools for Vaccination

    DTIC Science & Technology

    2003-01-01

    19], Borrelia burgdorferi [20] Chlamydia trachomatis [21] and Candida albicans [22]. C. albicans provides a paradigmatic example of how this ap... Borrelia burgdorferi -pulsed dendritic cells induce a protective immune response against tick-transmitted spirochetes, Infect. Immun. 65 (1997) 3386–3390

  8. Characterization of chicken dendritic cell markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. Lysophosphatidic acid induces osteocyte dendrite outgrowth.

    PubMed

    Karagiosis, Sue A; Karin, Norman J

    2007-05-25

    Osteocytes elaborate an extensive mechanosensory network in bone matrix and communicate intercellularly via gap junctions established at dendrite termini. We developed a method to measure osteocyte dendritogenesis in vitro using a modified transwell assay and determined that the lipid growth factor lysophosphatidic acid (LPA) is a potent stimulator of dendrite outgrowth in MLO-Y4 osteocytes. The stimulatory effects were dose-dependent with maximal outgrowth observed within a physiological range of LPA. LPA-treated osteocytes exhibited distinct rearrangements of the actin cytoskeleton and a more stellate morphology than control cells. LPA also promoted osteocyte chemotaxis, suggesting a shared molecular mechanism between dendrite outgrowth and cell motility. The LPA-induced increase in dendrite formation was blocked by the specific LPA-receptor antagonist Ki16425 and by pertussis toxin. Bone cells in vivo encounter platelet-derived LPA in regions of bone damage, and we postulate that this lipid factor is important for re-establishing osteocyte connectivity during fracture repair.

  10. Neuronal Actin Dynamics, Spine Density and Neuronal Dendritic Complexity Are Regulated by CAP2.

    PubMed

    Kumar, Atul; Paeger, Lars; Kosmas, Kosmas; Kloppenburg, Peter; Noegel, Angelika A; Peche, Vivek S

    2016-01-01

    Actin remodeling is crucial for dendritic spine development, morphology and density. CAP2 is a regulator of actin dynamics through sequestering G-actin and severing F-actin. In a mouse model, ablation of CAP2 leads to cardiovascular defects and delayed wound healing. This report investigates the role of CAP2 in the brain using Cap2(gt/gt) mice. Dendritic complexity, the number and morphology of dendritic spines were altered in Cap2(gt/gt) with increased number of excitatory synapses. This was accompanied by increased F-actin content and F-actin accumulation in cultured Cap2(gt/gt) neurons. Moreover, reduced surface GluA1 was observed in mutant neurons under basal condition and after induction of chemical LTP. Additionally, we show an interaction between CAP2 and n-cofilin, presumably mediated through the C-terminal domain of CAP2 and dependent on cofilin Ser3 phosphorylation. In vivo, the consequences of this interaction were altered phosphorylated cofilin levels and formation of cofilin aggregates in the neurons. Thus, our studies identify a novel role of CAP2 in neuronal development and neuronal actin dynamics.

  11. Neuronal Actin Dynamics, Spine Density and Neuronal Dendritic Complexity Are Regulated by CAP2

    PubMed Central

    Kumar, Atul; Paeger, Lars; Kosmas, Kosmas; Kloppenburg, Peter; Noegel, Angelika A.; Peche, Vivek S.

    2016-01-01

    Actin remodeling is crucial for dendritic spine development, morphology and density. CAP2 is a regulator of actin dynamics through sequestering G-actin and severing F-actin. In a mouse model, ablation of CAP2 leads to cardiovascular defects and delayed wound healing. This report investigates the role of CAP2 in the brain using Cap2gt/gt mice. Dendritic complexity, the number and morphology of dendritic spines were altered in Cap2gt/gt with increased number of excitatory synapses. This was accompanied by increased F-actin content and F-actin accumulation in cultured Cap2gt/gt neurons. Moreover, reduced surface GluA1 was observed in mutant neurons under basal condition and after induction of chemical LTP. Additionally, we show an interaction between CAP2 and n-cofilin, presumably mediated through the C-terminal domain of CAP2 and dependent on cofilin Ser3 phosphorylation. In vivo, the consequences of this interaction were altered phosphorylated cofilin levels and formation of cofilin aggregates in the neurons. Thus, our studies identify a novel role of CAP2 in neuronal development and neuronal actin dynamics. PMID:27507934

  12. Supramolecular dendritic polymers: from synthesis to applications.

    PubMed

    Dong, Ruijiao; Zhou, Yongfeng; Zhu, Xinyuan

    2014-07-15

    CONSPECTUS: Supramolecular dendritic polymers (SDPs), which perfectly combine the advantages of dendritic polymers with those of supramolecular polymers, are a novel class of non-covalently bonded, highly branched macromolecules with three-dimensional globular topology. Because of their dynamic/reversible nature, unique topological structure, and exceptional physical/chemical properties (e.g., low viscosity, high solubility, and a large number of functional terminal groups), SDPs have attracted increasing attention in recent years in both academic and industrial fields. In particular, the reversibility of non-covalent interactions endows SDPs with the ability to undergo dynamic switching of structure, morphology, and function in response to various external stimuli, such as pH, temperature, light, stress, and redox agents, which further provides a flexible and robust platform for designing and developing smart supramolecular polymeric materials and functional supramolecular devices. The existing SDPs can be systematically classified into the following six major types according to their topological features: supramolecular dendrimers, supramolecular dendronized polymers, supramolecular hyperbranched polymers, supramolecular linear-dendritic block copolymers, supramolecular dendritic-dendritic block copolymers, and supramolecular dendritic multiarm copolymers. These different types of SDPs possess distinct morphologies, unique architectures, and specific functions. Benefiting from their versatile topological structures as well as stimuli-responsive properties, SDPs have displayed not only unique characteristics or advantages in supramolecular self-assembly behaviors (e.g., controllable morphologies, specific performance, and facile functionalization) but also great potential to be promising candidates in various fields. In this Account, we summarize the recent progress in the synthesis, functionalization, and self-assembly of SDPs as well as their potential

  13. TSCOT+ thymic epithelial cell-mediated sensitive CD4 tolerance by direct presentation.

    PubMed

    Ahn, Sejin; Lee, Gwanghee; Yang, Soo Jung; Lee, Deokjae; Lee, Seunghyuk; Shin, Hyo Sun; Kim, Min Cheol; Lee, Kee Nyung; Palmer, Douglas C; Theoret, Marc R; Jenkinson, Eric J; Anderson, Graham; Restifo, Nicholas P; Kim, Moon Gyo

    2008-08-05

    Although much effort has been directed at dissecting the mechanisms of central tolerance, the role of thymic stromal cells remains elusive. In order to further characterize this event, we developed a mouse model restricting LacZ to thymic stromal cotransporter (TSCOT)-expressing thymic stromal cells (TDLacZ). The thymus of this mouse contains approximately 4,300 TSCOT+ cells, each expressing several thousand molecules of the LacZ antigen. TSCOT+ cells express the cortical marker CDR1, CD40, CD80, CD54, and major histocompatibility complex class II (MHCII). When examining endogenous responses directed against LacZ, we observed significant tolerance. This was evidenced in a diverse T cell repertoire as measured by both a CD4 T cell proliferation assay and an antigen-specific antibody isotype analysis. This tolerance process was at least partially independent of Autoimmune Regulatory Element gene expression. When TDLacZ mice were crossed to a novel CD4 T cell receptor (TCR) transgenic reactive against LacZ (BgII), there was a complete deletion of double-positive thymocytes. Fetal thymic reaggregate culture of CD45- and UEA-depleted thymic stromal cells from TDLacZ and sorted TCR-bearing thymocytes excluded the possibility of cross presentation by thymic dendritic cells and medullary epithelial cells for the deletion. Overall, these results demonstrate that the introduction of a neoantigen into TSCOT-expressing cells can efficiently establish complete tolerance and suggest a possible application for the deletion of antigen-specific T cells by antigen introduction into TSCOT+ cells.

  14. Dendritic mitochondria reach stable positions during circuit development.

    PubMed

    Faits, Michelle C; Zhang, Chunmeng; Soto, Florentina; Kerschensteiner, Daniel

    2016-01-07

    Mitochondria move throughout neuronal dendrites and localize to sites of energy demand. The prevailing view of dendritic mitochondria as highly motile organelles whose distribution is continually adjusted by neuronal activity via Ca(2+)-dependent arrests is based on observations in cultured neurons exposed to artificial stimuli. Here, we analyze the movements of mitochondria in ganglion cell dendrites in the intact retina. We find that whereas during development 30% of mitochondria are motile at any time, as dendrites mature, mitochondria all but stop moving and localize stably to synapses and branch points. Neither spontaneous nor sensory-evoked activity and Ca(2+) transients alter motility of dendritic mitochondria; and pathological hyperactivity in a mouse model of retinal degeneration elevates rather than reduces motility. Thus, our findings indicate that dendritic mitochondria reach stable positions during a critical developmental period of high motility, and challenge current views about the role of activity in regulating mitochondrial transport in dendrites.

  15. [Immunosuppressive acidic protein (IAP) in gynecologic malignant tumors and its relationship with other immunosuppressive substances and cell-mediated immunity].

    PubMed

    Takada, M

    1983-02-01

    We investigated the relationship between immunosuppressive acidic protein (IAP), an immunosuppressive substance determined in the body fluid from patients with cancer and the stages of cancer, and also its relationship with the progress of cancer during treatment and convalescence in 42 cases of ovary cancer, 47 cases of cancer of the uterine neck, 19 cases of cancer of the uterine body, and 5 cases of other of cancers. In addition, the relationship of IAP with other immunosuppressive substances and cell-mediated immunities was also investigated. The IAP level in the serum was not useful for early diagnosis of gynecologic malignant tumors, but it reflected on stages of cancer more accurately compared to levels of other immunosuppressive substances in the serum: alpha-antitripsine (alpha AT), alpha-glyco-protein (alpha AG), carcinoembrionic antigen (CEA), c-reactive protein (CRP), and serum ferritin (s-Fer), were useful as parameters showing progress of cancer during treatment and convalescence. The IAP level in the peritoneal fluid showed the same tendency. For the relationship with cell-mediated immunity, a stimulate index (SI) showed an inverse correlation from stage I; a T-cell count exhibited the same tendency; IgGFcR+ T-cell count showed a positive correlation in stage III; and ADCC exhibited an inverse correlation in stage III. However, immunosuppressive substances including IAP show high levels also in inflammatory diseases. Therefore, an appreciative value of IAP in the clinical area increases by being used for monitoring gynecologic cancer patients in combination with indicators of cell-mediated immunity, particularly, with SI.

  16. Cell mediated immune response after challenge in Omp25 liposome immunized mice contributes to protection against virulent Brucella abortus 544.

    PubMed

    Goel, Divya; Rajendran, Vinoth; Ghosh, Prahlad C; Bhatnagar, Rakesh

    2013-02-06

    Brucellosis is a disease affecting various domestic and wild life species, and is caused by a bacterium Brucella. Keeping in view the serious economic and medical consequences of brucellosis, efforts have been made to prevent the infection through the use of vaccines. Cell-mediated immune responses [CMI] involving interferon gamma and cytotoxic CD4(+) and CD8(+) T cells are required for removal of intracellular Brucella. Omp25 has been reported to be involved in virulence of Brucella melitensis, Brucella abortus and Brucella ovis. In our previous study, we have shown the protective efficacy of recombinant Omp25, when administered intradermally. In this study, the recombinant Omp25 was formulated in PC-PE liposomes and PLGA microparticles, to enhance the protective immunity generated by it. Significant protection was seen with prime and booster liposome immunization in Balb/c mice against virulent B. abortus 544 as it was comparable to B. abortus S-19 vaccine strain. However, microparticle prime and booster immunization failed to give better protection when compared to B. abortus S-19 vaccine strain. This difference can be attributed to the stimulation of cell mediated immune response in PC-PE liposome immunized mice even after challenge which converted to cytotoxicity seen in CD4(+) and CD8(+) enriched lymphocytes. However, in PLGA microparticle immunized mice, cell mediated immunity was not generated after challenge as observed by decreased cytotoxicity of CD4(+) and CD8(+) enriched lymphocytes. Our study emphasizes on the importance of liposome encapsulating Omp25 immunization in conferring protection against B. abortus 544 challenge in Balb/c mice with a single dose immunization regimen.

  17. Efficiency of Dendritic Cell Vaccination against B16 Melanoma Depends on the Immunization Route

    PubMed Central

    Edele, Fanny; Dudda, Jan C.; Bachtanian, Eva; Jakob, Thilo; Pircher, Hanspeter; Martin, Stefan F.

    2014-01-01

    Dendritic cells (DC) presenting tumor antigens are crucial to induce potent T cell-mediated anti-tumor immune responses. Therefore DC-based cancer vaccines have been established for therapy, however clinical outcomes are often poor and need improvement. Using a mouse model of B16 melanoma, we found that the route of preventive DC vaccination critically determined tumor control. While repeated DC vaccination did not show an impact of the route of DC application on the prevention of tumor growth, a single DC vaccination revealed that both the imprinting of skin homing receptors and an enhanced proliferation state of effector T cells was seen only upon intracutaneous but not intravenous or intraperitoneal immunization. Tumor growth was prevented only by intracutaneous DC vaccination. Our results indicate that under suboptimal conditions the route of DC vaccination crucially determines the efficiency of tumor defense. DC-based strategies for immunotherapy of cancer should take into account the immunization route in order to optimize tissue targeting of tumor antigen specific T cells. PMID:25121970

  18. The Role of Dendritic Cells in Fibrosis Progression in Nonalcoholic Fatty Liver Disease

    PubMed Central

    Almeda-Valdes, Paloma; Aguilar Olivos, Nancy E.; Barranco-Fragoso, Beatriz; Uribe, Misael; Méndez-Sánchez, Nahum

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most frequent cause of chronic liver disease. NAFLD encompasses a wide range of pathologies, from simple steatosis to steatosis with inflammation to fibrosis. The pathogenesis of NAFLD progression has not been completely elucidated, and different liver cells could be implicated. This review focuses on the current evidence of the role of liver dendritic cells (DCs) in the progression from NAFLD to fibrosis. Liver DCs are a heterogeneous population of hepatic antigen-presenting cells; their main function is to induce T-cell mediated immunity by antigen processing and presentation to T cells. During the steady state liver DCs are immature and tolerogenic. However, in an environment of chronic inflammation, DCs are transformed to potent inducers of immune responses. There is evidence about the role of DC in liver fibrosis, but it is not clearly understood. Interestingly, there might be a link between lipid metabolism and DC function, suggesting that immunogenic DCs are associated with liver lipid storage, representing a possible pathophysiological mechanism in NAFLD development. A better understanding of the interaction between inflammatory pathways and the different cell types and the effect on the progression of NAFLD is of great relevance. PMID:26339640

  19. Muramyl dipeptide-Lys stimulates the function of human dendritic cells.

    PubMed

    Todate, A; Suda, T; Kuwata, H; Chida, K; Nakamura, H

    2001-11-01

    Muramyl dipeptide (MDP)-Lys (L18), a synthetic MDP analogue derived from bacterial cell walls, has been reported to be a potent immunoadjuvant that enhances protective immunity against pathogens and tumors by stimulating immune-competent cells, such as monocytes and macrophages. However, it is not known whether MDP-Lys modulates the function of dendritic cells (DCs), which are the most potent antigen-presenting cells and play a crucial role in initiating T cell-mediated immunity. Therefore, we examined the effects of MDP-Lys on the expression of surface molecules, cytokine production, and antigen-presenting function of human DCs generated from peripheral blood cells in the presence of interleukin (IL)-4 and granulocyte-macrophage colony-stimulating factor. We found that MDP-Lys markedly up-regulated the expression of CD80, CD83, CD86, and CD40, but not human leukocyte antigen-DR, and stimulated the production of tumor necrosis factor-alpha, IL-6, IL-8, IL-10, and IL-12 (p40) by human DCs in a dose-dependent manner. Furthermore, MDP-Lys-treated DCs showed enhanced antigen-presenting function compared with untreated DCs, as assessed by an allogeneic mixed lymphocyte reaction. These results suggested that the immunoadjuvant activity of MDP-Lys in vivo is mediated, in part, by its stimulation of DC function.

  20. Selective suppression of interleukin-12 induction after macrophage receptor ligation.

    PubMed

    Sutterwala, F S; Noel, G J; Clynes, R; Mosser, D M

    1997-06-02

    Interleukin (IL)-12 is a monocyte- and macrophage-derived cytokine that plays a crucial role in both the innate and the acquired immune response. In this study, we examined the effects that ligating specific macrophage receptors had on the induction of IL-12 by lipopolysaccharide (LPS). We report that ligation of the macrophage Fcgamma, complement, or scavenger receptors inhibited the induction of IL-12 by LPS. Both mRNA synthesis and protein secretion were diminished to near-undetectable levels following receptor ligation. Suppression was specific to IL-12 since IL-10 and tumor necrosis factor-alpha (TNF-alpha) production were not inhibited by ligating macrophage receptors. The results of several different experimental approaches suggest that IL-12 downregulation was due to extracellular calcium influxes that resulted from receptor ligation. First, preventing extracellular calcium influxes, by performing the assays in EGTA, abrogated FcgammaR-mediated IL-12(p40) mRNA suppression. Second, exposure of macrophages to the calcium ionophores, ionomycin or A23187, mimicked receptor ligation and inhibited IL-12(p40) mRNA induction by LPS. Finally, bone marrow-derived macrophages from FcR gamma chain-deficient mice, which fail to flux calcium after receptor ligation, failed to inhibit IL-12(p40) mRNA induction. These results indicate that the calcium influxes that occur as a result of receptor ligation are responsible for inhibiting the induction of IL-12 by LPS. Hence, the ligation of phagocytic receptors on macrophages can lead to a dramatic decrease in IL-12 induction. This downregulation may be a way of limiting proinflammatory responses of macrophages to extracellular pathogens, or suppressing the development of cell-mediated immunity to intracellular pathogens.

  1. Sequential inductive learning

    SciTech Connect

    Gratch, J.

    1996-12-31

    This article advocates a new model for inductive learning. Called sequential induction, it helps bridge classical fixed-sample learning techniques (which are efficient but difficult to formally characterize), and worst-case approaches (which provide strong statistical guarantees but are too inefficient for practical use). Learning proceeds as a sequence of decisions which are informed by training data. By analyzing induction at the level of these decisions, and by utilizing the only enough data to make each decision, sequential induction provides statistical guarantees but with substantially less data than worst-case methods require. The sequential inductive model is also useful as a method for determining a sufficient sample size for inductive learning and as such, is relevant to learning problems where the preponderance of data or the cost of gathering data precludes the use of traditional methods.

  2. Humoral and cell-mediated immune responses in DNA immunized mink challenged with wild-type canine distemper virus.

    PubMed

    Nielsen, Line; Søgaard, Mette; Karlskov-Mortensen, Peter; Jensen, Trine Hammer; Jensen, Tove Dannemann; Aasted, Bent; Blixenkrone-Møller, Merete

    2009-07-30

    The aim of the study was to investigate the different phases of the immune response after DNA immunization with the hemagglutinin and nucleoprotein genes from canine distemper virus (CDV). Although attenuated live CDV vaccines have effective