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Sample records for mouse dendritic cells

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

    PubMed

    Segura, Elodie; Amigorena, Sebastian

    2015-01-01

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

  2. Generation of mouse and human dendritic cells in vitro.

    PubMed

    Guo, Xueheng; Zhou, Yifan; Wu, Tao; Zhu, Xinyi; Lai, Wenlong; Wu, Li

    2016-05-01

    Dendritic cells (DC) that can orchestrate immune responses and maintain host homeostasis, are indispensable components of the immune system. Although distributed widely in many lymphoid and non-lymphoid tissues, their rarity in number has become a limiting factor for DC related research and therapies. Therefore, methods for efficiently generating large numbers of DC resembling their in vivo counterparts are urgently needed for DC related research and therapies. Herein we summarize the current methods for generating mouse and human DC in vitro and hope that these will facilitate both studies of DC biology and their clinical applications.

  3. Organization of pyramidal cell apical dendrites and composition of dendritic clusters in the mouse: emphasis on primary motor cortex.

    PubMed

    Lev, D L; White, E L

    1997-02-01

    It has been proposed that neurons in sensory cortices are organized into modules that centre on clusters of apical dendrites belonging to layer V pyramidal neurons. In the present study, sections reacted for microtubule-associated protein (MAP2) were examined in order to determine the three-dimensional inter-relationships of pyramidal cell dendrites in mouse primary motor cortex (MsI) cortex. Results indicate that pyramidal cell dendrites in MsI cortex can be interpreted to be arranged in a modular fashion, and that these modules are organized similarly to those in the sensory areas of the cortex. Also included in the present study are experiments designed to determine if the clusters of apical dendrites, around which the modules are centred, are composed of dendrites belonging to one or to more than one type of projection cell. Callosal neurons in MsI cortex were labelled by the retrograde transport of horseradish peroxidase deposited onto severed callosal fibres in the contralateral hemisphere. Examination of tangential thin sections through layer IV of MsI cortex shows clusters of apical dendrites in which every dendrite is labelled with horseradish peroxidase. Adjacent clusters are composed of unlabelled dendrites, suggesting that the apical dendrites of callosal neurons aggregate to form clusters that are composed exclusively of dendrites belonging to this type of projection cell. These findings suggest a hitherto unsuspected degree of specificity in the cellular composition of cortical modules.

  4. Clusters of synaptic inputs on dendrites of layer 5 pyramidal cells in mouse visual cortex

    PubMed Central

    Gökçe, Onur; Bonhoeffer, Tobias; Scheuss, Volker

    2016-01-01

    The spatial organization of synaptic inputs on the dendritic tree of cortical neurons plays a major role for dendritic integration and neural computations, yet, remarkably little is known about it. We mapped the spatial organization of glutamatergic synapses between layer 5 pyramidal cells by combining optogenetics and 2-photon calcium imaging in mouse neocortical slices. To mathematically characterize the organization of inputs we developed an approach based on combinatorial analysis of the likelihoods of specific synapse arrangements. We found that the synapses of intralaminar inputs form clusters on the basal dendrites of layer 5 pyramidal cells. These clusters contain 4 to 14 synapses within ≤30 µm of dendrite. According to the spatiotemporal characteristics of synaptic summation, these numbers suggest that there will be non-linear dendritic integration of synaptic inputs during synchronous activation. DOI: http://dx.doi.org/10.7554/eLife.09222.001 PMID:27431612

  5. DSCAM promotes refinement in the mouse retina through cell death and restriction of exploring dendrites.

    PubMed

    Li, Shuai; Sukeena, Joshua M; Simmons, Aaron B; Hansen, Ethan J; Nuhn, Renee E; Samuels, Ivy S; Fuerst, Peter G

    2015-04-08

    In this study we develop and use a gain-of-function mouse allele of the Down syndrome cell adhesion molecule (Dscam) to complement loss-of-function models. We assay the role of Dscam in promoting cell death, spacing, and laminar targeting of neurons in the developing mouse retina. We find that ectopic or overexpression of Dscam is sufficient to drive cell death. Gain-of-function studies indicate that Dscam is not sufficient to increase spatial organization, prevent cell-to-cell pairing, or promote active avoidance in the mouse retina, despite the similarity of the Dscam loss-of-function phenotype in the mouse retina to phenotypes observed in Drosophila Dscam1 mutants. Both gain- and loss-of-function studies support a role for Dscam in targeting neurites; DSCAM is necessary for precise dendrite lamination, and is sufficient to retarget neurites of outer retinal cells after ectopic expression. We further demonstrate that DSCAM guides dendrite targeting in type 2 dopaminergic amacrine cells, by restricting the stratum in which exploring retinal dendrites stabilize, in a Dscam dosage-dependent manner. Based on these results we propose a single model to account for the numerous Dscam gain- and loss-of-function phenotypes reported in the mouse retina whereby DSCAM eliminates inappropriately placed cells and connections.

  6. Nectin-1 spots as a novel adhesion apparatus that tethers mitral cell lateral dendrites in a dendritic meshwork structure of the developing mouse olfactory bulb.

    PubMed

    Inoue, Takahito; Fujiwara, Takeshi; Rikitake, Yoshiyuki; Maruo, Tomohiko; Mandai, Kenji; Kimura, Kazushi; Kayahara, Tetsuro; Wang, Shujie; Itoh, Yu; Sai, Kousyoku; Mori, Masahiro; Mori, Kensaku; Mizoguchi, Akira; Takai, Yoshimi

    2015-08-15

    Mitral cells project lateral dendrites that contact the lateral and primary dendrites of other mitral cells and granule cell dendrites in the external plexiform layer (EPL) of the olfactory bulb. These dendritic structures are critical for odor information processing, but it remains unknown how they are formed. In immunofluorescence microscopy, the immunofluorescence signal for the cell adhesion molecule nectin-1 was concentrated on mitral cell lateral dendrites in the EPL of the developing mouse olfactory bulb. In electron microscopy, the immunogold particles for nectin-1 were symmetrically localized on the plasma membranes at the contacts between mitral cell lateral dendrites, which showed bilateral darkening without dense cytoskeletal undercoats characteristic of puncta adherentia junctions. We named the contacts where the immunogold particles for nectin-1 were symmetrically accumulated "nectin-1 spots." The nectin-1 spots were 0.21 μm in length on average and the distance between the plasma membranes was 20.8 nm on average. In 3D reconstruction of serial sections, clusters of the nectin-1 spots formed a disc-like structure. In the mitral cell lateral dendrites of nectin-1-knockout mice, the immunogold particles for nectin-1 were undetectable and the plasma membrane darkening was electron-microscopically normalized, but the plasma membranes were partly separated from each other. The nectin-1 spots were further identified between mitral cell lateral and primary dendrites and between mitral cell lateral dendrites and granule cell dendritic spine necks. These results indicate that the nectin-1 spots constitute a novel adhesion apparatus that tethers mitral cell dendrites in a dendritic meshwork structure of the developing mouse olfactory bulb.

  7. Epithelial basal cells are distinct from dendritic cells and macrophages in the mouse epididymis.

    PubMed

    Shum, Winnie W; Smith, Tegan B; Cortez-Retamozo, Virna; Grigoryeva, Lubov S; Roy, Jeremy W; Hill, Eric; Pittet, Mikael J; Breton, Sylvie; Da Silva, Nicolas

    2014-05-01

    The epithelium that lines the epididymal duct establishes the optimal milieu in which spermatozoa mature, acquire motility, and are stored. This finely tuned environment also protects antigenic sperm against pathogens and autoimmunity, which are potential causes of transient or permanent infertility. The epididymal epithelium is pseudostratified and contains basal cells (BCs) that are located beneath other epithelial cells. Previous studies showed that in the mouse epididymis, BCs possess macrophage-like characteristics. However, we previously identified a dense population of cells belonging to the mononuclear phagocyte (MP) system (comprised of macrophages and dendritic cells) in the basal compartment of the mouse epididymis and showed that a subset of MPs express the macrophage marker F4/80. In the present study, we evaluate the distribution of BCs and MPs in the epididymis of transgenic CD11c-EYFP mice, in which EYFP is expressed exclusively in MPs, using antibodies against the BC marker keratin 5 (KRT5) and the macrophage marker F4/80. Immunofluorescence labeling for laminin, a basement membrane marker, showed that BCs and most MPs are located in the basal region of the epithelium. Confocal microscopy showed that in the initial segment, both BCs and MPs project intraepithelial extensions and establish a very intricate network. Flow cytometry experiments demonstrated that epididymal MPs and BCs are phenotypically distinct. BCs do not express F4/80, and MPs do not express KRT5. Therefore, despite their proximity and some morphological similarities with peritubular macrophages and dendritic cells, BCs do not belong to the MP system.

  8. Effects of CHO-expressed recombinant lactoferrins on mouse dendritic cell presentation and function.

    PubMed

    Hwang, Shen-An; Kruzel, Marian L; Actor, Jeffrey K

    2015-07-01

    Lactoferrin (LF), a natural iron-binding protein, has previously demonstrated effectiveness in enhancing the Bacillus Calmette-Guérin (BCG) tuberculosis vaccine. This report investigates immune modulatory effects of Chinese hamster ovary (CHO) cell-expressed recombinant mouse and human LFs on mouse bone marrow-derived dendritic cells (BMDCs), comparing homologous and heterologous functions. BCG-infected BMDCs were cultured with LF, and examined for class II presentation molecule expression. Culturing of BCG-infected BMDCs with either LF decreased the class II molecule-expressing population. Mouse LF significantly increased the production of IL-12p40, IL-1β and IL-10, while human LF-treated BMDCs increased only IL-1β and IL-10. Overlaying naïve CD4 T-cells onto BCG-infected BMDCs cultured with mouse LF increased IFN-γ, whereas the human LF-exposed group increased IFN-γ and IL-17 from CD4 T cells. Overlay of naïve CD8 T cells onto BCG-infected BMDCs treated with mouse LF increased the production of IFN-γ and IL-17, while similar experiments using human LF only increased IL-17. This report is the first to examine mouse and human recombinant LFs in parallel experiments to assess murine DC function. These results detail the efficacy of the human LF counterpart used in a heterologous system to understand LF-mediated events that confer BCG efficacy against Mycobacterium tuberculosis challenge.

  9. Establishment of a cell line with features of early dendritic cell precursors from fetal mouse skin.

    PubMed

    Girolomoni, G; Lutz, M B; Pastore, S; Assmann, C U; Cavani, A; Ricciardi-Castagnoli, P

    1995-08-01

    During ontogeny, the skin is progressively populated by major histocompatibility complex class II-negative dendritic cell (DC) precursors that then mature into efficient antigen-presenting cells (APC). To characterize these DC progenitors better, we generated myeloid cell lines from fetal mouse skin by infecting cell suspensions with a retroviral vector carrying an envAKR-mycMH2 fusion gene. These cells, represented by the line FSDC, displayed a dendritic morphology and their proliferation in serum-free medium was promoted by granulocyte/macrophage colony-stimulating factor (GM-CSF), but not macrophage-CSF. FSDC expressed strong surface-membrane ATP/ADPase activity, intracellular staining for 2A1 antigen, and a surface phenotype consistent with a myeloid precursor: H-2d,b+, I-Ad,b+, CD54+, CD11b+, CD11c+, 2.4G2+, F4/80+, CD44+, 2F8+, ER-MP 12-, Sca-1+, Sca-2+, NLDC-145-, B7.2+, B7.1-, J11d-, B220-, Thy-1-, and CD3-. FSDC stimulated poorly allogeneic or syngeneic T cells in the primary mixed-leukocyte reaction, and markedly increased this function after treatment with GM-CSF, GM-CSF and interleukin (IL)-4 or interferon-gamma (IFN-gamma); in contrast, stem cell factor, IL-1 alpha and tumor necrosis factor-alpha had no effect. Preculture with IFN-gamma was required for presentation of haptens to primed T cells in vitro. However, FSDC, even after cytokine activation, were less potent APC than adult epidermal Langerhans cells in both of the above assays. Finally, FSDC derivatized with haptens and injected either intravenously or subcutaneously could efficiently induce contact sensitivity responses in naive syngeneic mice. The results indicate that fetal mouse skin is colonized by myeloid precursors possessing a macrophage/immature DC-like surface phenotype and priming capacity in vivo. These cells need further differentiation and activation signals (e.g. cytokines) to express their antigen presenting potential in vitro.

  10. Dendritic Calcium Signaling in ON and OFF Mouse Retinal Ganglion Cells

    PubMed Central

    Margolis, David J.; Gartland, Andrew J.; Euler, Thomas; Detwiler, Peter B.

    2010-01-01

    Retinal ganglion cells (RGCs) are the output cells of the retina; they convert synaptic input into spike output that carries visual information to the brain. Synaptic inputs are received, integrated and communicated to the spike initiation zone of the axon by dendrites whose properties are poorly understood. Here simultaneous patch clamp recording and 2-photon Ca2+ imaging are used to study voltage- and light-evoked Ca2+ signals in the dendrites of identified types of mouse RGCs from parallel ON and OFF pathways, which encode the onset and offset of light, respectively. The results show pathway-specific differences in voltage-dependent Ca2+ signaling. While both ON and OFF cells express high-voltage-activated (HVA) Ca2+ channels, only OFF RGCs also express low-voltage-activated (LVA) Ca2+ channels. LVA Ca2+ channels in OFF cells are de-inactivated by hyperpolarization from the resting potential and give rise to rebound excited Ca2+ spikes at the termination of a step of either hyperpolarizing current or light. This suggests that the differential expression of voltage-gated Ca2+ channels in ON and OFF RGC dendrites contribute to differences in the way the two cell types process visual stimuli. PMID:20505081

  11. The Change of Immunoactivity of Dendritic Cells Induced by Mouse 4-1BBL Recombinant Adenovirus

    PubMed Central

    Youlin, Kuang; Xiaodong, Weng; Zhiyuan, Chen; Hengcheng, Zhu; Hui, Chen; Botao, Jiang

    2010-01-01

    Purpose The purpose of this study is to construct a recombinant adenovirus vector carrying mouse 4-1BBL and observe its effects in dendritic cells. Materials and Methods Mouse 4-1BBL cDNA was taken from the plasmid pcDNA3-m4-1BBL and subcloned into adenovirus shuttle plasmid pAdTrack-CMV, and then transformed into competent BJ5183 with plasmid pAdEasy-1. After recombination in E. coli, Ad-4-1BBL was packaged and amplified in HEK 293 cells. The expression of 4-1BBL in Ad-4-1BBL-transfected mouse prostate cancer cell line RM-1 was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. After the co-culture of dendritic cells (DCs) with Ad-4-1BBL-transfected RM-1 cells, interleukin (IL)-6 and IL-12 production were assessed by enzyme-linked immunosorbent assay (ELISA) and co-stimulatary moleculs (CD80 and CD86) on DCs were analyzed by flow cytometry. Results The levels of IL-6 (3,960 pg/mL) and IL-12 (249 pg/mL) production in Ad-m4-1BBL-pulsed DCs were more than those in none-pulsed DCs. The differences were statistically significant (p < 0.05). The expression of co-stimulatary molecules (CD80 and CD86) was up-regulated in Ad-m4-1BBL-pulsed DCs. Conclusion The results indicated the recombinant mouse 4-1BBL can effectively activate DCs. PMID:20499429

  12. Morphine inhibits Purkinje cell survival and dendritic differentiation in organotypic cultures of the mouse cerebellum

    PubMed Central

    Hauser, Kurt F.; Gurwell, Julie A.; Turbek, Carol S.

    2015-01-01

    The effects of morphine on the morphogenesis and survival of calbindin-D28kimmunoreactive Purkinje cells was studied in organotypic explant cultures isolated from 1- or 7-day-old mouse cerebella. To reduce experimental variability, bilaterally matched pairs of organotypic cultures were used to compare the effects of opiate drug treatment. One explant within each pair was untreated, while the remaining explant was continuously treated for 7 to 10 days with morphine, morphine plus naloxone, or naloxone alone. In explants derived from 1-day-old mice, morphine treatment significantly reduced Purkinje cell dendritic length compared to symmetrically-matched untreated control explants. The concentration of morphine estimated to cause a half-maximal reduction (EC50) in dendritic length was 4.9 × 10−8 M. At higher concentrations (EC50 = 3.6 × 10−6 M), morphine also significantly decreased the number of Purkinje cells in explants from 1-day-old mice compared to untreated explants. Electron microscopy identified increased numbers of degenerating Purkinje cells in explants derived from 1-day-old mice. This showed that high concentrations (10−5 M) of morphine reduced Purkinje cell numbers by decreasing their rate of survival. In explants derived from 7-day-old mice, morphine (10−5 M) neither affected Purkinje cell dendritic length nor cell numbers compared to symmetrically-matched untreated (control) explants. Collectively, these findings suggest that morphine per se, through a direct action on the cerebellum, can affect Purkinje cell differentiation and survival. The results additionally suggest there is a critical period during development when Purkinje cells are especially vulnerable to the effects of morphine. PMID:7821399

  13. Brucella β 1,2 Cyclic Glucan Is an Activator of Human and Mouse Dendritic Cells

    PubMed Central

    Martirosyan, Anna; Pérez-Gutierrez, Camino; Banchereau, Romain; Dutartre, Hélène; Lecine, Patrick; Dullaers, Melissa; Mello, Marielle; Pinto Salcedo, Suzana; Muller, Alexandre; Leserman, Lee; Levy, Yves; Zurawski, Gerard; Zurawski, Sandy; Moreno, Edgardo; Moriyón, Ignacio; Klechevsky, Eynav; Banchereau, Jacques; Oh, SangKon; Gorvel, Jean-Pierre

    2012-01-01

    Bacterial cyclic glucans are glucose polymers that concentrate within the periplasm of alpha-proteobacteria. These molecules are necessary to maintain the homeostasis of the cell envelope by contributing to the osmolarity of Gram negative bacteria. Here, we demonstrate that Brucella β 1,2 cyclic glucans are potent activators of human and mouse dendritic cells. Dendritic cells activation by Brucella β 1,2 cyclic glucans requires TLR4, MyD88 and TRIF, but not CD14. The Brucella cyclic glucans showed neither toxicity nor immunogenicity compared to LPS and triggered antigen-specific CD8+ T cell responses in vivo. These cyclic glucans also enhanced antigen-specific CD4+ and CD8+ T cell responses including cross-presentation by different human DC subsets. Brucella β 1,2 cyclic glucans increased the memory CD4+ T cell responses of blood mononuclear cells exposed to recombinant fusion proteins composed of anti-CD40 antibody and antigens from both hepatitis C virus and Mycobacterium tuberculosis. Thus cyclic glucans represent a new class of adjuvants, which might contribute to the development of effective antimicrobial therapies. PMID:23166489

  14. Brucella β 1,2 cyclic glucan is an activator of human and mouse dendritic cells.

    PubMed

    Martirosyan, Anna; Pérez-Gutierrez, Camino; Banchereau, Romain; Dutartre, Hélène; Lecine, Patrick; Dullaers, Melissa; Mello, Marielle; Salcedo, Suzana Pinto; Muller, Alexandre; Leserman, Lee; Levy, Yves; Zurawski, Gerard; Zurawski, Sandy; Moreno, Edgardo; Moriyón, Ignacio; Klechevsky, Eynav; Banchereau, Jacques; Oh, Sangkon; Gorvel, Jean-Pierre

    2012-01-01

    Bacterial cyclic glucans are glucose polymers that concentrate within the periplasm of alpha-proteobacteria. These molecules are necessary to maintain the homeostasis of the cell envelope by contributing to the osmolarity of Gram negative bacteria. Here, we demonstrate that Brucella β 1,2 cyclic glucans are potent activators of human and mouse dendritic cells. Dendritic cells activation by Brucella β 1,2 cyclic glucans requires TLR4, MyD88 and TRIF, but not CD14. The Brucella cyclic glucans showed neither toxicity nor immunogenicity compared to LPS and triggered antigen-specific CD8(+) T cell responses in vivo. These cyclic glucans also enhanced antigen-specific CD4(+) and CD8(+) T cell responses including cross-presentation by different human DC subsets. Brucella β 1,2 cyclic glucans increased the memory CD4(+) T cell responses of blood mononuclear cells exposed to recombinant fusion proteins composed of anti-CD40 antibody and antigens from both hepatitis C virus and Mycobacterium tuberculosis. Thus cyclic glucans represent a new class of adjuvants, which might contribute to the development of effective antimicrobial therapies.

  15. Dendritic Cells Cause Bone Lesions in a New Mouse Model of Histiocytosis

    PubMed Central

    Grosjean, Frédéric; Nasi, Sonia; Schneider, Pascal; Chobaz, Véronique; Liu, Alexandra; Mordasini, Vanessa; Moullec, Kristell; Vezzoni, Paolo; Lavanchy, Christine; Busso, Nathalie; Acha-Orbea, Hans; Ehirchiou, Driss

    2015-01-01

    Langerhans cell histiocytosis (LCH) is a rare disease caused by the clonal accumulation of dendritic Langerhans cells, which is often accompanied by osteolytic lesions. It has been reported that osteoclast-like cells play a major role in the pathogenic bone destruction seen in patients with LCH and these cells are postulated to originate from the fusion of DCs. However, due to the lack of reliable animal models the pathogenesis of LCH is still poorly understood. In this study, we have established a mouse model of histiocytosis- recapitulating human disease for osteolytic lesions seen in LCH patients. At 12 weeks after birth, severe bone lesions were observed in our multisystem histiocytosis (Mushi) model, when CD8α conventional dendritic cells (DCs) are transformed (MuTuDC) and accumulate. Most importantly, our study demonstrates that bone loss in LCH can be accounted for the transdifferentiation of MuTuDCs into functional osteoclasts both in vivo and in vitro. Moreover, we have shown that injected MuTuDCs reverse the osteopetrotic phenotype of oc/oc mice in vivo. In conclusion, our results support a crucial role of DCs in bone lesions in histiocytosis patients. Furthermore, our new model of LCH based on adoptive transfer of MuTuDC lines, leading to bone lesions within 1–2 weeks, will be an important tool for investigating the pathophysiology of this disease and ultimately for evaluating the potential of anti-resorptive drugs for the treatment of bone lesions. PMID:26247358

  16. Circadian expression of clock genes in mouse macrophages, dendritic cells, and B cells

    PubMed Central

    Silver, Adam C.; Arjona, Alvaro; Hughes, Michael E.; Nitabach, Michael N.; Fikrig, Erol

    2012-01-01

    In mammals, circadian and daily rhythms influence nearly all aspects of physiology, ranging from behavior to gene expression. Functional molecular clocks have been described in the murine spleen and splenic NK cells. The aim of our study was to investigate the existence of molecular clock mechanisms in other immune cells. Therefore, we measured the circadian changes in gene expression of clock genes (Per1, Per2, Bmal1, and Clock) and clock-controlled transcription factors (Rev-erbα and Dbp) in splenic enriched macrophages, dendritic cells, and B cells in both mice entrained to a light-dark cycle and under constant environmental conditions. Our study reveals the existence of functional molecular clock mechanisms in splenic macrophages, dendritic cells, and B cells. PMID:22019350

  17. Role of Dendritic Cells in the Immune Response Induced by Mouse Mammary Tumor Virus Superantigen

    PubMed Central

    Baribaud, Frédéric; Maillard, Ivan; Vacheron, Sonia; Brocker, Thomas; Diggelmann, Heidi; Acha-Orbea, Hans

    1999-01-01

    After mouse mammary tumor virus (MMTV) infection, B lymphocytes present a superantigen (Sag) and receive help from the unlimited number of CD4+ T cells expressing Sag-specific T-cell receptor Vβ elements. The infected B cells divide and differentiate, similarly to what occurs in classical B-cell responses. The amplification of Sag-reactive T cells can be considered a primary immune response. Since B cells are usually not efficient in the activation of naive T cells, we addressed the question of whether professional antigen-presenting cells such as dendritic cells (DCs) are responsible for T-cell priming. We show here, using MMTV(SIM), a viral isolate which requires major histocompatibility complex class II I-E expression to induce a strong Sag response in vivo, that transgenic mice expressing I-E exclusively on DCs (I-EαDC tg) reveal a strong Sag response. This Sag response was dependent on the presence of B cells, as indicated by the absence of stimulation in I-EαDC tg mice lacking B cells (I-EαDC tg μMT−/−), even if these B cells lack I-E expression. Furthermore, the involvement of either residual transgene expression by B cells or transfer of I-E from DCs to B cells was excluded by the use of mixed bone marrow chimeras. Our results indicate that after priming by DCs in the context of I-E, the MMTV(SIM) Sag can be recognized on the surface of B cells in the context of I-A. The most likely physiological relevance of the lowering of the antigen threshold required for T-cell/B-cell collaboration after DC priming is to allow B cells with a low affinity for antigen to receive T-cell help in a primary immune response. PMID:10482591

  18. Effects of mesenchymal stromal cells on human myeloid dendritic cell differentiation and maturation in a humanized mouse model.

    PubMed

    Chen, Ping; Huang, Yanfei; Womer, Karl L

    2015-12-01

    Mesenchymal stromal cells (MSCs) have shown promise as cellular therapy in allogeneic transplantation, although the precise mechanisms underlying their benefit in clinical trials are difficult to study. We previously demonstrated that MSCs exert immunoregulatory effects in mouse bone marrow-derived dendritic cell (DC) culture. Since mouse studies do not reliably reproduce human events, we used a humanized mouse model to study the immunomodulatory effects of human MSCs on human DC immunobiology. Humanized mice were established by injection of cord blood CD34(+) cells into NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl/SzJ) (NOD scid gamma, NSG) mice. Human cells were detected in the mouse bone marrow, blood, and spleen 12weeks after transplantation. Human DCs were differentiated from humanized mouse bone marrow cells during human MSC co-culture. MSCs inhibited DC differentiation and kept DCs in an immature state as demonstrated by phenotype and function. In conclusion, humanized mouse models represent a useful method to study the function of human MSCs on human DC immunobiology.

  19. Barley low molecular weight β-glucan potently induces maturation of mouse dendritic cells.

    PubMed

    Tanioka, Asuka; An, Wei-Wei; Kuge, Takao; Tsubaki, Kazufumi; Nakaya, Kazuyasu

    2011-05-01

    Accumulating evidence indicates that non-toxic immunostimulants with strong differentiation/maturation-inducing activity for dendritic cells (DCs) might be useful for preventing or even curing cancer. Mouse bone marrow (BM) cells were cultured in the presence of various glucans and their differentiation/maturation-inducing activities were compared by measuring cytokines secreted in the culture medium. Barley-derived β-glucan with an average molecular weight of 2 kDa (BBG-Low) remarkably stimulated the formation of mature DCs from immature mouse DCs. The amount of interleukin-6 produced by sequential treatment of BM cells with granulocyte-macrophage colony-stimulating factor and 10 μg/mL of BBG-Low was approximately 30 times higher than that obtained by a similar sequential treatment using barley β-glucan of 40-70 kDa instead of BBG-Low. BBG-Low induces the formation of mature DCs from immature DCs and suggests that BBG-Low will be useful as a potent nontoxic immunostimulator.

  20. Altered lymph node composition in diphtheria toxin receptor-based mouse models to ablate dendritic cells

    PubMed Central

    van Blijswijk, Janneke; Schraml, Barbara U.; Rogers, Neil C.; Whitney, Paul G.; Zelenay, Santiago; Acton, Sophie E.; Sousa, Caetano Reis e

    2014-01-01

    Dendritic cells (DCs) are key regulators of innate and adaptive immunity. Our understanding of immune function has benefited greatly from mouse models allowing for selective ablation of DCs. Many such models rely on transgenic diphtheria toxin receptor (DTR) expression driven by DC-restricted promoters. This renders DCs sensitive to DT but is otherwise thought to have no effect on immune physiology. Here, we report that, unexpectedly, mice in which DTR is expressed on conventional DCs display marked lymph node (LN) hypocellularity and reduced frequency of DCs in the same organs but not in spleen or non-lymphoid tissues. Intriguingly, in mixed bone marrow (BM) chimeras the phenotype conferred by DTR-expressing DCs is dominant over control BM-derived cells, leading to small LNs and an overall paucity of DCs independently of the genetic ability to express DTR. The finding of alterations in LN composition and size independently of diphtheria toxin challenge suggests that caution must be exercised when interpreting results of experiments obtained with mouse models to inducibly deplete DCs. It further indicates that DTR, a member of the epidermal growth factor family, is biologically active in mice. Its use in cell ablation experiments needs to be considered in light of this activity. PMID:25411201

  1. Dendritic cells and macrophages in the uveal tract of the normal mouse eye

    PubMed Central

    McMenamin, P.

    1999-01-01

    BACKGROUND/AIMS—Dendritic cells (DC) and macrophages are components of the immune cell populations in the uveal tract whose density, distribution, turnover, and function may play a role in the maintenance of immunological homeostasis in the eye. Little is known of these cells in the mouse eye despite this being the predominant experimental model in many studies of ocular immune responses and immunoinflammatory mediated eye diseases. The aim of the present study was to obtain further immunophenotypic data on resident tissue macrophages and DC populations in the mouse uveal tract.
METHODS—Pieces of iris, ciliary body, and choroid dissected from perfusion fixed BALB/c mice were incubated whole in a variety of anti-macrophage and DC monoclonal antibodies (mAbs). Labelled cells were visualised using either single or double immunoperoxidase techniques.
RESULTS—Quantitative analysis and double immunolabelling revealed that 80% of F4/80+ cells (a mAb that recognises both DC and macrophages) in the iris are macrophages (SER4+). The iris contained a network of Ia+ cells (412 (SD 130) cells/mm2) of which two thirds appear to be DC. A similar pattern was observed in the ciliary body and choroid. Only a few DC in the uveal tract were very weakly reactive for mAbs which recognise B7-1 (CD80), B7-2 (CD86), β2 integrin (mAb N418), and multivesicular bodies associated with antigen presentation (mAb M342).
CONCLUSIONS—The present study reveals that the mouse uveal tract, like the rat, contains rich networks of DC and resident tissue macrophages. The networks of resident tissue macrophages in the mouse uveal tract closely resemble similar networks in non-ocular tissues. The phenotype of uveal tract DC suggests they are in the "immature" phase of their life cycle, similar to Langerhans cells of the skin, thus implying their role in situ within the eye is antigen capture and not antigen presentation.

 PMID:10216062

  2. Expression patterns of H2-O in mouse B cells and dendritic cells correlate with cell function.

    PubMed

    Fallas, Jennifer L; Yi, Woelsung; Draghi, Nicole A; O'Rourke, Helen M; Denzin, Lisa K

    2007-02-01

    In the endosomes of APCs, the MHC class II-like molecule H2-M catalyzes the exchange of class II-associated invariant chain peptides (CLIP) for antigenic peptides. H2-O is another class II-like molecule that modulates the peptide exchange activity of H2-M. Although the expression pattern of H2-O in mice has not been fully evaluated, H2-O is expressed by thymic epithelial cells, B cells, and dendritic cells (DCs). In this study, we investigated H2-O, H2-M, and I-A(b)-CLIP expression patterns in B cell subsets during B cell development and activation. H2-O was first detected in the transitional 1 B cell subset and high levels were maintained in marginal zone and follicular B cells. H2-O levels were down-regulated specifically in germinal center B cells. Unexpectedly, we found that mouse B cells may have a pool of H2-O that is not associated with H2-M. Additionally, we further evaluate H2-O and H2-M interactions in mouse DCs, as well as H2-O expression in bone marrow-derived DCs. We also evaluated H2-O, H2-M, I-A(b), and I-A(b)-CLIP expression in splenic DC subsets, in which H2-O expression levels varied among the splenic DC subsets. Although it has previously been shown that H2-O modifies the peptide repertoire, H2-O expression did not alter DC presentation of a number of endogenous and exogenous Ags. Our further characterization of H2-O expression in DCs, as well as the identification of a potential free pool of H2-O in mouse splenic B cells, suggest that H2-O may have a yet to be elucidated role in immune responses.

  3. Synaptogenesis and synaptic protein localization in the postnatal development of rod bipolar cell dendrites in mouse retina.

    PubMed

    Anastassov, Ivan A; Wang, Weiwei; Dunn, Felice A

    2017-05-25

    Retinal responses to photons originate in rod photoreceptors and are transmitted to the ganglion cell output of the retina through the primary rod bipolar pathway. At the first synapse of this pathway, input from multiple rods is pooled into individual rod bipolar cells. This architecture is called convergence. Convergence serves to improve sensitivity of rod vision when photons are sparse. Establishment of convergence depends on the development of a proper complement of dendritic tips and transduction proteins in rod bipolar cells. How the dendrites of rod bipolar cells develop and contact the appropriate number of rods is unknown. To answer this question we visualized individual rod bipolar cells in mouse retina during postnatal development and quantified the number of dendritic tips, as well as the expression of transduction proteins within dendrites. Our findings show that the number of dendritic tips in rod bipolar cells increases monotonically during development. The number of tips at P21, P30, and P82 exceeds the previously reported rod convergence ratios, and the majority of these tips are proximal to a presynaptic rod release site, suggesting more rods provide input to a rod bipolar cell. We also show that dendritic transduction cascade members mGluR6 and TRPM1 appear in tips with different timelines. These finding suggest that (a) rod bipolar cell dendrites elaborate without pruning during development, (b) the convergence ratio between rods and rod bipolar cells may be higher than previously reported, and (c) mGluR6 and TRPM1 are trafficked independently during development. © 2017 Wiley Periodicals, Inc.

  4. Immunomodulatory properties of Brucella melitensis lipopolysaccharide determinants on mouse dendritic cells in vitro and in vivo.

    PubMed

    Zhao, Yun; Hanniffy, Sean; Arce-Gorvel, Vilma; Conde-Alvarez, Raquel; Oh, SangKon; Moriyón, Ignacio; Mémet, Sylvie; Gorvel, Jean-Pierre

    2017-10-02

    The lipopolysaccharide (LPS) is a major virulence factor of Brucella, a facultative intracellular pathogenic Gram-negative bacterium. Brucella LPS exhibits a low toxicity and its atypical structure was postulated to delay the host immune response, favouring the establishment of chronic disease. Here we carried out an in-depth in vitro and in vivo characterisation of the immunomodulatory effects of Brucella LPS on different dendritic cell (DC) subpopulations. By using LPSs from bacteria that share some of Brucella LPS structural features, we demonstrated that the core component of B. melitensis wild-type (Bm-wt) LPS accounts for the low activation potential of Brucella LPS in mouse GM-CSF-derived (GM-) DCs. Contrary to the accepted dogma considering Brucella LPS a poor TLR4 agonist and DC activator, Bm-wt LPS selectively induced expression of surface activation markers and cytokine secretion from Flt3-Ligand-derived (FL-) DCs in a TLR4-dependent manner. It also primed in vitro T cell proliferation by FL-DCs. In contrast, modified LPS with a defective core purified from Brucella carrying a mutated wadC gene (Bm-wadC), efficiently potentiated mouse and human DC activation and T cell proliferation in vitro. In vivo, Bm-wt LPS promoted scant activation of splenic DC subsets and limited recruitment of monocyte- DC like cells in the spleen, conversely to Bm-wadC LPS. Bm-wadC live bacteria drove high cytokine secretion levels in sera of infected mice. Altogether, these results illustrate the immunomodulatory properties of Brucella LPS and the enhanced DC activation ability of the wadC mutation with potential for vaccine development targeting Brucella core LPS structure.

  5. Plasmacytoid dendritic cells alter the antitumor activity of CpG-oligodeoxynucleotides in a mouse model of lung carcinoma.

    PubMed

    Sorrentino, Rosalinda; Morello, Silvana; Luciano, Antonio; Crother, Timothy R; Maiolino, Piera; Bonavita, Eduardo; Arra, Claudio; Adcock, Ian M; Arditi, Moshe; Pinto, Aldo

    2010-10-15

    The effect of CpG-oligodeoxynucleotides (CpG) has been studied on a number of tumors. Although CpG may facilitate tumor regression in mouse models of melanoma, its activity in lung cancer is unclear. The aim of our study was to elucidate the effect of CpG (0.5-50 μg/mouse) in a mouse model of Lewis lung carcinoma cell-induced lung cancer. Lung tumor growth increased at 3 and 7 d after a single administration of CpG. This was associated with a greater influx of plasmacytoid dendritic cells (pDCs), immature myeloid dendritic cells, and greater recruitment of regulatory T cells. Depletion of pDCs using a specific Ab (m927) reversed the immune-suppressive environment and resulted in a decreased lung tumor burden, accompanied by a greater influx of active myeloid dendritic cells and CD8(+) T cells, and a higher production of Th1- and Th17-like cytokines. Furthermore, the rate of apoptosis in the lungs of mice treated with CpG increased following the depletion of pDCs. CpG treatment alone does not lead to tumor regression in the lung. However, ablation of pDCs renders CpG a good adjuvant for lung cancer chemotherapy in this experimental model.

  6. Constitutive activation of neuronal Src causes aberrant dendritic morphogenesis in mouse cerebellar Purkinje cells.

    PubMed

    Kotani, Takenori; Morone, Nobuhiro; Yuasa, Shigeki; Nada, Shigeyuki; Okada, Masato

    2007-02-01

    Src family tyrosine kinases are essential for neural development, but their in vivo functions remain elusive because of functional compensation among family members. To elucidate the roles of individual Src family members in vivo, we generated transgenic mice expressing the neuronal form of c-Src (n-Src), Fyn, and their constitutively active forms in cerebellar Purkinje cells using the L7 promoter. The expression of the constitutively active n-Src retarded the postnatal development of Purkinje cells and disrupted dendritic morphogenesis, whereas the wild-type n-Src had only moderate effects. Neither wild-type nor constitutively active Fyn over-expression significantly affected Purkinje-cell morphology. The aberrant Purkinje cells in n-Src transgenic mice retained multiple dendritic shafts extending in non-polarized directions and were located heterotopically in the molecular layer. Ultrastructural observation of the dendritic shafts revealed that the microtubules of n-Src transgenic mice were more densely and irregularly arranged, and had structural deformities. In primary culture, Purkinje cells from n-Src transgenic mice developed abnormally thick dendritic shafts and large growth-cone-like structures with poorly extended dendrites, which could be rescued by treatment with a selective inhibitor of Src family kinases, PP2. These results suggest that n-Src activity regulates the dendritic morphogenesis of Purkinje cells through affecting microtubule organization.

  7. 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.

  8. Inhibition of Protease-Activated Receptor 1 Does not Affect Dendritic Homeostasis of Cultured Mouse Dentate Granule Cells

    PubMed Central

    Schuldt, Gerlind; Galanis, Christos; Strehl, Andreas; Hick, Meike; Schiener, Sabine; Lenz, Maximilian; Deller, Thomas; Maggio, Nicola; Vlachos, Andreas

    2016-01-01

    Protease-activated receptors (PARs) are widely expressed in the central nervous system (CNS). While a firm link between PAR1-activation and functional synaptic and intrinsic neuronal properties exists, studies on the role of PAR1 in neural structural plasticity are scarce. The physiological function of PAR1 in the brain remains not well understood. We here sought to determine whether prolonged pharmacologic PAR1-inhibition affects dendritic morphologies of hippocampal neurons. To address this question we employed live-cell microscopy of mouse dentate granule cell dendrites in 3-week old entorhino-hippocampal slice cultures prepared from Thy1-GFP mice. A subset of cultures were treated with the PAR1-inhibitor SCH79797 (1 μM; up to 3 weeks). No major effects of PAR1-inhibition on static and dynamic parameters of dentate granule cell dendrites were detected under control conditions. Granule cells of PAR1-deficient slice cultures showed unaltered dendritic morphologies, dendritic spine densities and excitatory synaptic strength. Furthermore, we report that PAR1-inhibition does not prevent dendritic retraction following partial deafferentation in vitro. Consistent with this finding, no major changes in PAR1-mRNA levels were detected in the denervated dentate gyrus (DG). We conclude that neural PAR1 is not involved in regulating the steady-state dynamics or deafferentation-induced adaptive changes of cultured dentate granule cell dendrites. These results indicate that drugs targeting neural PAR1-signals may not affect the stability and structural integrity of neuronal networks in healthy brain regions. PMID:27378862

  9. Maturation Stages of Mouse Dendritic Cells in Growth Factor–dependent Long-Term Cultures

    PubMed Central

    Winzler, Claudia; Rovere, Patrizia; Rescigno, Maria; Granucci, Francesca; Penna, Giuseppe; Adorini, Luciano; Zimmermann, Valerie S.; Davoust, Jean; Ricciardi-Castagnoli, Paola

    1997-01-01

    The signals controlling the checkpoints of dendritic cells (DC) maturation and the correlation between phenotypical and functional maturational stages were investigated in a defined model system of growth factor–dependent immature mouse DC. Three sequential stages of DC maturation (immature, mature, and apoptotic) were defined and characterized. Immature DC (stage 1) had low expression of costimulatory molecules, highly organized cytoskeleton, focal adhesion plaques, and slow motility; accordingly, they were very efficient in antigen uptake and processing of soluble proteins. Further, at this stage most of major histocompatibility complex class II molecules were within cytoplasmic compartments consistent with a poor allostimulatory capacity. Bacteria or cytokines were very efficient in inducing progression from stage 1 towards stage 2 (mature). Morphological changes were observed by confocal analysis including depolymerization of F-actin and loss of vinculin containing adhesive structures which correlates with acquisition of high motility. Antigen uptake and presentation of native protein antigen was reduced. In contrast, presentation of immunogenic peptides and allostimulatory activity became very efficient and secretion of IL-12 p75 was detectable after antigen presentation. This functional DC maturation ended by apoptotic cell death, and no reversion to the immature phenotype was observed. PMID:9016880

  10. Sustained Ocular Hypertension Induces Dendritic Degeneration of Mouse Retinal Ganglion Cells That Depends on Cell Type and Location

    PubMed Central

    Feng, Liang; Zhao, Yan; Yoshida, Miho; Chen, Hui; Yang, Jessica F.; Kim, Ted S.; Cang, Jianhua; Troy, John B.; Liu, Xiaorong

    2013-01-01

    Purpose. Glaucoma is characterized by retinal ganglion cell (RGC) death and frequently associated with elevated IOP. How RGCs degenerate before death is little understood, so we sought to investigate RGC degeneration in a mouse model of ocular hypertension. Methods. A laser-induced mouse model of chronic ocular hypertension mimicked human high-tension glaucoma. Immunohistochemistry was used to characterize overall RGC loss and an optomotor behavioral test to measure corresponding changes in visual capacity. Changes in RGC functional properties were characterized by a large-scale multielectrode array (MEA). The transgenic Thy-1-YFP mouse line, in which a small number of RGCs are labeled with yellow fluorescent protein (YFP), permitted investigation of whether subtypes of RGCs or RGCs from particular retinal areas were differentially vulnerable to elevated IOP. Results. Sustained IOP elevation in mice was achieved by laser photocoagulation. We confirmed RGC loss and decreased visual acuity in ocular hypertensive mice. Furthermore, these mice had fewer visually responsive cells with smaller receptive field sizes compared to controls. We demonstrated that RGC dendritic shrinkage started from the vertical axis of hypertensive eyes and that mono-laminated ON cells were more susceptible to IOP elevation than bi-laminated ON-OFF cells. Moreover, a subgroup of ON RGCs labeled by the SMI-32 antibody exhibited significant dendritic atrophy in the superior quadrant of the hypertensive eyes. Conclusions. RGC degeneration depends on subtype and location in hypertensive eyes. This study introduces a valuable model to investigate how the structural and functional degeneration of RGCs leads to visual impairments. PMID:23322576

  11. Mannan derivatives induce phenotypic and functional maturation of mouse dendritic cells

    PubMed Central

    Sheng, Kuo-Ching; Pouniotis, Dodie S; Wright, Mark D; Kit Tang, Choon; Lazoura, Eliada; Pietersz, Geoffrey A; Apostolopoulos, Vasso

    2006-01-01

    Mannan, a polysaccharide isolated from yeast binds to C-type lectins of the mannose receptor family, expressed by antigen-presenting cells (APCs) including dendritic cells (DCs) and macrophages. As these receptors mediate endocytosis, they have been targeted with ligands to deliver antigens into APCs to initiate immune responses. Immunization with tumour antigen MUC1 conjugated to oxidized mannan (OM) or reduced mannan (RM) induced differential immune responses in mice, and only mice immunized with OM-MUC1 elicited strong MUC1-specific cytotoxic T lymphocyte responses and protected mice from a MUC1 tumour challenge. In this study, the adjuvant effect of mannan and its derivatives including OM and RM, in comparison to lipopolysaccharide, on DCs were investigated. Mannan, OM and RM were capable of stimulating mouse bone marrow-derived DC in vitro, eliciting enhanced allogeneic T-cell proliferation and enhancing OTI/OTII peptide-specific T-cell responses. Injection of mice with mannan, OM and RM induced a mature phenotype of lymph node and splenic DCs. Analysis by reverse transcription—polymerase chain reaction indicated that Manna, OM and RM also stimulated up-regulation of inflammatory cytokines including interleukin-1β and tumour necrosis factor-α, and differential T helper 1 (Th1)/Th2 cytokines. Subsequent experiments demonstrated that activation of DCs was Toll-like receptor-4-dependent. The data presented here, together with evidence reported previously on OM and RM in induction of immune responses in vivo, suggest that OM and RM exert a dual capacity to target antigen to APCs as well as mature DCs. PMID:16827898

  12. EVIDENCE OF CELL-NONAUTONOMOUS CHANGES IN DENDRITE AND DENDRITIC SPINE MORPHOLOGY IN THE MET-SIGNALING DEFICIENT MOUSE FOREBRAIN

    PubMed Central

    Judson, Matthew C.; Eagleson, Kathie L.; Wang, Lily; Levitt, Pat

    2010-01-01

    Human genetic findings and murine neuroanatomical expression mapping have intersected to implicate Met receptor tyrosine kinase signaling in the development of forebrain circuits controlling social and emotional behaviors that are atypical in autism spectrum disorders (ASD). To clarify roles for Met signaling during forebrain circuit development in vivo, we generated mutant mice (Emx1Cre/Metfx/fx) with an Emx1-Cre-driven deletion of signaling-competent Met in dorsal pallially-derived forebrain neurons. Morphometric analyses of Lucifer Yellow-injected pyramidal neurons in postnatal day 40 anterior cingulate cortex (ACC) revealed no statistically significant changes in total dendritic length, but a selective reduction in apical arbor length distal to the soma in Emx1Cre/Metfx/fx neurons relative to wild type, consistent with a decrease in the total tissue volume sampled by individual arbors in the cortex. The effects on dendritic structure appear to be circuit-selective, as basal arbor length was increased in Emx1Cre/Metfx/fx layer 2/3 neurons. Spine number was not altered on Emx1Cre/Metfx/fx pyramidal cell populations studied, but spine head volume was significantly increased (~20%). Cell-nonautonomous, circuit-level influences of Met signaling on dendritic development were confirmed by studies of medium spiny neurons (MSN), which do not express Met, but receive Met-expressing corticostriatal afferents during development. Emx1Cre/Metfx/fx MSN exhibited robust increases in total arbor length (~20%). Like in the neocortex, average spine head volume was also increased (~12%). These data demonstrate that a developmental loss of presynaptic Met receptor signaling can affect postsynaptic morphogenesis and suggest a mechanism whereby attenuated Met signaling could disrupt both local and long-range connectivity within circuits relevant to ASD. PMID:20853516

  13. Cross-Presentation of Cell-Associated Antigens by Mouse Splenic Dendritic Cell Populations

    PubMed Central

    Thacker, Robert I.; Janssen, Edith M.

    2012-01-01

    Cross-presentation of cell-associated antigens (Ag) plays an important role in the induction of anti-tumor responses, autoimmune diseases, and transplant rejection. While several dendritic cell (DC) populations can induce pro-inflammatory CD8+ T cell responses to cell-associated Ag during infection, in the absence of infection, cross-priming of naïve CD8+ T cells is highly restricted. Comparison of the main splenic DC populations in mice – including the classic, cross-presenting CD8α DC and the recently described merocytic DC (mcDC) – reveals that cross-priming DCs display a distinct phenotype in cell-associated Ag uptake, endosomal/lysosomal trafficking, lysosomal acidification, and Ag persistence compared to non-cross-priming DC populations. Although the CD8α DC and mcDC subsets utilize similar processing pathways to cross-present cell-associated Ag, cross-priming by CD8α DCs is associated with IL-12 production, while the superior priming of the mcDC is critically dependent on type I IFN production. This discussion illustrates how subtle differences in internal processing pathways and their signaling sequelae significantly affect the duration of Ag cross-presentation and cytokine production by DCs, thereby shaping the ensuing CD8+ T cell response. PMID:22566924

  14. Levels of dendritic cell populations and regulatory T cells vary significantly between two commonly used mouse strains.

    PubMed

    Vogelsang, Petra; Hovden, Arnt-Ove; Jonsson, Roland; Appel, Silke

    2009-12-01

    Dendritic cells (DC) are a heterogeneous group of professional antigen-presenting cells (APC) involved in both initiating immune responses and maintaining tolerance. Roughly, DC can be divided into plasmacytoid DC (pDC) and conventional DC (cDC). By controlling regulatory T cells (Treg), DC can influence the outcome of both immunity and autoimmunity. Since the use of mice as in vivo models became a practical tool for researchers studying pathological events in all kind of human diseases, we decided to compare levels of cDC, pDC and Treg in both spleen and blood between two inbred mouse strains. Here we show that two commonly used mouse strains, BALB/c and C57BL/10J mice, have significantly different levels of distinct CD11c(+)/CD4(-)/CD8a(+), CD11c(+)/CD4(+)/CD8a(-) and CD11c(+)/CD4(-)/CD8a(-) cDC populations, pDC and Treg. Therefore, we emphasize the importance of considering the proper model when comparing data sets from different mouse strains.

  15. Dendritic Cells are Critical Accessory Cells for Thymus-Dependent Antibody Responses in Mouse and in Man

    NASA Astrophysics Data System (ADS)

    Inaba, Kayo; Steinman, Ralph M.; van Voorhis, Wesley C.; Muramatsu, Shigeru

    1983-10-01

    We report that dendritic cells (DC) are necessary and potent accessory cells for anti-sheep erythrocyte responses in both mouse and man. In mice, a small number of DC (0.3-1% of the culture) restores the response of B/T-lymphocyte mixtures to that observed in unfractionated spleen. An even lower dose (0.03-0.1% DC) is needed if the T cells have been primed to antigen. Responses are both antigen and T cell dependent. Selective depletion of DC from unfractionated spleen with the monoclonal antibody 33D1 and complement ablates the antibody response. In contrast to DC, purified spleen macrophages are weak or inactive stimulators. However, when mixed with DC, macrophages can increase the yield of antibody-secreting cells about 2-fold. In man, small numbers (0.3-1%) of blood DC stimulate antibody formation in vitro. Purified human monocytes do not stimulate but in low doses (1% of the culture) inhibit the antibody response. Likewise, selective removal of human monocytes with antibody and complement enhances or accelerates the development of antibody-secreting cells. We conclude that DC are required for the development of T-dependent antibody responses by mouse and human lymphocytes in vitro.

  16. Soluble TNF Regulates TACE via AP-2α Transcription Factor in Mouse Dendritic Cells.

    PubMed

    Ge, Lisheng; Vujanovic, Nikola L

    2017-01-01

    Dendritic cells (DCs), the essential immunoregulatory and APCs, are major producers of the central mediator of inflammation, soluble TNF-α (sTNF). sTNF is generated by TNF-α converting enzyme (TACE) proteolytic release of the transmembrane TNF (tmTNF) ectodomain. The mechanisms of TACE and sTNF regulation in DCs remain elusive. This study newly defines that sTNF regulates TACE in mouse DCs by engaging the AP-2α transcription factor. We found that the expression of AP-2α was higher, whereas the expression and activity of TACE were lower, in wild-type DCs (wtDCs) than in TNF knockout (TNFko) DCs. Exogenous sTNF rapidly and simultaneously induced increases of AP-2α expression and decreases of TACE expression and activity in wtDCs and TNFko DCs, indicating that AP-2α and TACE are inversely dependent on sTNF and are functionally associated. To define this functional association, we identified an AP-2α binding site in TACE promoter and demonstrated, using EMSAs and chromatin immunoprecipitation assays, that AP-2α could bind to TACE promoter in a TNF-dependent manner. Additionally, sTNF simultaneously enhanced AP-2α expression and decreased TACE promoter luciferase activity in DCs. Similarly, transfection of AP-2α cDNA decreased TACE promoter luciferase activity, TACE expression, and TACE enzymatic activity in wtDCs or TNFko DCs. In contrast, transfection of AP-2α small interfering RNA increased TACE promoter luciferase activity, TACE expression, and TACE enzymatic activity in wtDCs. These results show that TACE is a target of, and is downregulated by, sTNF-induced AP-2α transcription factor in DCs.

  17. Network of dendritic cells within the muscular layer of the mouse intestine

    PubMed Central

    Flores-Langarica, Adriana; Meza-Perez, Selene; Calderon-Amador, Juana; Estrada-Garcia, Teresa; MacPherson, Gordon; Lebecque, Serge; Saeland, Sem; Steinman, Ralph M.; Flores-Romo, Leopoldo

    2005-01-01

    Dendritic cells (DCs) are located at body surfaces such as the skin, respiratory and genital tracts, and intestine. To further analyze intestinal DCs, we adapted an epidermal sheet separation technique and obtained two intestinal layers, facing the lumen and serosa. Unexpectedly, immunolabeling of the layer toward the serosa revealed a regular, dense, planar network of cells with prominent dendritic morphology within the external muscular layer and with increasing frequency along the length of the intestine. Direct examination of the serosal-disposed layers showed a significant fraction of the DCs to express DEC-205/CD205, CD11c, Langerin/CD207, Fcγ receptor/CD16/32, CD14, and low levels of activation markers, CD25, CD80, CD86, and CD95. By more sensitive FACS analyses, cells from this layer contained two CD11c+ populations of CD45+ CD205+, CD19- leukocytes, MHC II+ and MHC II-. When ovalbumin conjugated to an anti-DEC-205 antibody was injected into mice, the conjugate targeted to these DCs, which upon isolation were able to stimulate ovalbumin-specific, CD4+ and CD8+ T cell antigen receptor-transgenic T cells. In vivo, these DCs responded to two microbial stimuli, systemic LPS and oral live bacteria, by up-regulating CD80, CD86, DEC-205, and Langerin within 12 h. This network of DCs thus represents a previously unrecognized antigen-presenting cell system in the intestine. PMID:16361439

  18. The Role of Plasmacytoid and Myeloid Dendritic Cells in Induction of Asthma in a Mouse Model and the Effect of a TLR9 Agonist on Dendritic Cells.

    PubMed

    Mo, Ji-Hun; Chung, Young-Jun; Hayashi, Tomoko; Lee, Jongdae; Raz, Eyal

    2011-07-01

    To determine the role of plasmacytoid dendritic cells (pDC) and myeloid dendritic cells (mDC) in priming effector T cells to induce allergy, and to evaluate the effect of immunostimulatory sequences (ISS, TLR9 agonist) on dendritic cells. Cultured mDC and pDC with/without ISS were injected intratracheally into sensitized Balb/C mice. Mice were sacrificed, and then pulmonary function tests, bronchoalveolar lavage (BAL), cell counts, and cytokine levels were evaluated. Migration of dendritic cells was also evaluated after ISS administration. In mice injected with mDC, airway hyperresponsiveness, eosinophil counts, and Th2 cytokine levels in BAL increased with increasing numbers of mDC injected. However, in mice injected with pDC, none of these changed, suggesting poor priming of T cells by pDC. In addition, mDC pulsed with ISS inhibited asthmatic reactions, and ISS administration inhibited migration of DC to the lung. We suggest that pDC played a limited role in priming T cells in this asthma model and that mDC played a major role in inducing asthma. In addition, ISS inhibited migration of DC to the lung.

  19. Novel insights into the relationships between dendritic cell subsets in human and mouse revealed by genome-wide expression profiling

    PubMed Central

    Robbins, Scott H; Walzer, Thierry; Dembélé, Doulaye; Thibault, Christelle; Defays, Axel; Bessou, Gilles; Xu, Huichun; Vivier, Eric; Sellars, MacLean; Pierre, Philippe; Sharp, Franck R; Chan, Susan; Kastner, Philippe; Dalod, Marc

    2008-01-01

    Background Dendritic cells (DCs) are a complex group of cells that play a critical role in vertebrate immunity. Lymph-node resident DCs (LN-DCs) are subdivided into conventional DC (cDC) subsets (CD11b and CD8α in mouse; BDCA1 and BDCA3 in human) and plasmacytoid DCs (pDCs). It is currently unclear if these various DC populations belong to a unique hematopoietic lineage and if the subsets identified in the mouse and human systems are evolutionary homologs. To gain novel insights into these questions, we sought conserved genetic signatures for LN-DCs and in vitro derived granulocyte-macrophage colony stimulating factor (GM-CSF) DCs through the analysis of a compendium of genome-wide expression profiles of mouse or human leukocytes. Results We show through clustering analysis that all LN-DC subsets form a distinct branch within the leukocyte family tree, and reveal a transcriptomal signature evolutionarily conserved in all LN-DC subsets. Moreover, we identify a large gene expression program shared between mouse and human pDCs, and smaller conserved profiles shared between mouse and human LN-cDC subsets. Importantly, most of these genes have not been previously associated with DC function and many have unknown functions. Finally, we use compendium analysis to re-evaluate the classification of interferon-producing killer DCs, lin-CD16+HLA-DR+ cells and in vitro derived GM-CSF DCs, and show that these cells are more closely linked to natural killer and myeloid cells, respectively. Conclusion Our study provides a unique database resource for future investigation of the evolutionarily conserved molecular pathways governing the ontogeny and functions of leukocyte subsets, especially DCs. PMID:18218067

  20. Inhibitory and immunological effects induced by the combination of photodynamic therapy and dendritic cells on mouse transplanted hepatoma.

    PubMed

    Zhang, Nan-zheng; Bai, Shuang; Cai, Xiao-jun; Li, Li-bo

    2016-03-01

    To investigate the anti-tumor and immune efficacy of photodynamic immune-therapy (PIT), the combination of photodynamic therapy and dendritic cells (DC), on murine Heps hepatoma. DCs were derived from syngeneic mouse bone marrow and then labeled with DAPI in vitro. The hepatoma model was established by subcutaneous inoculation with Heps cells in one hundred and twenty-eight mice. They were then divided into four groups at random: control group, PDT group, DC group and PIT group. Tumors in the control group were injected with normal saline. Mice in the PDT group were injected with the photosensitizer Deuteporfin 24 h before irradiation. Mice in the DC group were injected with DAPI labeled dendritic cells intratumorally. Mice in the PIT group were further given an injection of DCs after photoirradiation. Tumor growth and survival time were recorded after treatment. Fluorescence of tumor draining lymph nodes was evaluated under fluorescence microscope. Cytotoxic activity of splenocytes was tested by standard lactate dehydrogenase (lactate dehydrogenase, LDH) release assay. (1) Tumor growth was significantly slowed down in the PDT and PIT group compared to the control group (P<0.01). (2) The mean survival time was significantly prolonged in the PDT and PIT group. (3) The number of fluorescent cells in the draining lymph nodes from DC group was higher than that of the PIT group. (4) The anti-tumor activity of splenocytes in the PDT and PIT group was significantly higher than that of the DC and control groups (P<0.01, P<0.01). The present study suggests that PDT can inhibit tumor growth and induce anti-tumour immune response. The combination of PDT induced by Deuteporfiin and dendritic cell is capable of amplifying the antitumor immune response. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Effect of Matrix Metallopeptidase 13 on the Function of Mouse Bone Marrow-derived Dendritic Cells

    PubMed Central

    Li, Xiao-Dong; Zhang, Xin-Rui; Li, Zhi-Hao; Yang, Yang; Zhang, Duo; Zheng, Heng; Dong, Shu-Ying; Chen, Juan; Zeng, Xian-Dong

    2017-01-01

    Background: Dendritic cells are professional antigen-presenting cells found in an immature state in epithelia and interstitial space, where they capture antigens such as pathogens or damaged tissue. Matrix metallopeptidase 13 (MMP-13), a member of the collagenase subfamily, is involved in many different cellular processes and is expressed in murine bone marrow-derived dendritic cells (DCs). The function of MMP-13 in DCs is not well understood. Here, we investigated the effect of MMP-13 on DC maturation, apoptosis, and phagocytosis. Methods: Bone marrow-derived dendritic cells were obtained from C57BL/6 mice. One short-interfering RNA specific for MMP-13 was used to transfect DCs. MMP-13-silenced DCs and control DCs were prepared, and apoptosis was measured using real-time polymerase chain reaction and Western blotting. MMP-13-silenced DCs and control DCs were analyzed for surface expression of CD80 and CD86 and phagocytosis capability using flow cytometry. Results: Compared to the control DCs, MMP-13-silenced DCs increased expression of anti-apoptosis-related genes, BAG1 (control group vs. MMP-13-silenced group: 4.08 ± 0.60 vs. 6.11 ± 0.87, P = 0.008), BCL-2 (control group vs. MMP-13-silenced group: 7.54 ± 0.76 vs. 9.54 ± 1.29, P = 0.036), and TP73 (control group vs. MMP-13-silenced group: 4.33 ± 0.29 vs. 5.60 ± 0.32, P = 0.001) and decreased apoptosis-related genes, CASP1 (control group vs. MMP-13-silenced group: 3.79 ± 0.67 vs. 2.54 ± 0.39, P = 0.019), LTBR (control group vs. MMP-13-silenced group: 9.23 ± 1.25 vs. 6.24 ± 1.15, P = 0.012), and CASP4 (control group vs. MMP-13-silenced group: 2.07 ± 0.56 vs. 0.35 ± 0.35, P = 0.002). Protein levels confirmed the same expression pattern. MMP-13-silenced groups decreased expression of CD86 on DCs; however, there was no statistical difference in CD80 surface expression. Furthermore, MMP-13-silenced groups exhibited weaker phagocytosis capability. Conclusion: These results indicate that MMP-13 inhibition

  2. Stimulatory effect of Echinacea purpurea extract on the trafficking activity of mouse dendritic cells: revealed by genomic and proteomic analyses.

    PubMed

    Yin, Shu-Yi; Wang, Wen-Hsin; Wang, Bi-Xue; Aravindaram, Kandan; Hwang, Pei-Ing; Wu, Han-Ming; Yang, Ning-Sun

    2010-11-01

    Several Echinacea species have been used as nutraceuticals or botanical drugs for "immunostimulation", but scientific evidence supporting their therapeutic use is still controversial. In this study, a phytocompound mixture extracted from the butanol fraction (BF) of a stem and leaf (S+L) extract of E. purpurea ([BF/S+L/Ep]) containing stringently defined bioactive phytocompounds was obtained using standardized and published procedures. The transcriptomic and proteomic effects of this phytoextract on mouse bone marrow-derived dendritic cells (BMDCs) were analyzed using primary cultures. Treatment of BMDCs with [BF/S+L/Ep] did not significantly influence the phenotypic maturation activity of dendritic cells (DCs). Affymetrix DNA microarray and bioinformatics analyses of genes differentially expressed in DCs treated with [BF/S+L/Ep] for 4 or 12 h revealed that the majority of responsive genes were related to cell adhesion or motility (Cdh10, Itga6, Cdh1, Gja1 and Mmp8), or were chemokines (Cxcl2, Cxcl7) or signaling molecules (Nrxn1, Pkce and Acss1). TRANSPATH database analyses of gene expression and related signaling pathways in treated-DCs predicted the JNK, PP2C-α, AKT, ERK1/2 or MAPKAPK pathways as the putative targets of [BF/S+L/Ep]. In parallel, proteomic analysis showed that the expressions of metabolic-, cytoskeleton- or NF-κB signaling-related proteins were regulated by treatment with [BF/S+L/Ep]. In vitro flow cytometry analysis of chemotaxis-related receptors and in vivo cell trafficking assay further showed that DCs treated with [BF/S+L/Ep] were able to migrate more effectively to peripheral lymph node and spleen tissues than DCs treated as control groups. Results from this study suggest that [BF/S+L/Ep] modulates DC mobility and related cellular physiology in the mouse immune system. Moreover, the signaling networks and molecules highlighted here are potential targets for nutritional or clinical application of Echinacea or other candidate medicinal

  3. Brucella discriminates between mouse dendritic cell subsets upon in vitro infection.

    PubMed

    Papadopoulos, Alexia; Gagnaire, Aurélie; Degos, Clara; de Chastellier, Chantal; Gorvel, Jean-Pierre

    2016-01-01

    Brucella is a Gram-negative bacterium responsible for brucellosis, a worldwide re-emerging zoonosis. Brucella has been shown to infect and replicate within Granulocyte macrophage colony-stimulating factor (GMCSF) in vitro grown bone marrow-derived dendritic cells (BMDC). In this cell model, Brucella can efficiently control BMDC maturation. However, it has been shown that Brucella infection in vivo induces spleen dendritic cells (DC) migration and maturation. As DCs form a complex network composed by several subpopulations, differences observed may be due to different interactions between Brucella and DC subsets. Here, we compare Brucella interaction with several in vitro BMDC models. The present study shows that Brucella is capable of replicating in all the BMDC models tested with a high infection rate at early time points in GMCSF-IL15 DCs and Flt3l DCs. GMCSF-IL15 DCs and Flt3l DCs are more activated than the other studied DC models and consequently intracellular bacteria are not efficiently targeted to the ER replicative niche. Interestingly, GMCSF-DC and GMCSF-Flt3l DC response to infection is comparable. However, the key difference between these 2 models concerns IL10 secretion by GMCSF DCs observed at 48 h post-infection. IL10 secretion can explain the weak secretion of IL12p70 and TNFα in the GMCSF-DC model and the low level of maturation observed when compared to GMCSF-IL15 DCs and Flt3l DCs. These models provide good tools to understand how Brucella induce DC maturation in vivo and may lead to new therapeutic design using DCs as cellular vaccines capable of enhancing immune response against pathogens.

  4. Infection of mouse bone marrow-derived immature dendritic cells with classical swine fever virus C-strain promotes cells maturation and lymphocyte proliferation.

    PubMed

    Zheng, Fu-Ying; Qiu, Chang-Qing; Jia, Huai-Jie; Chen, Guo-Hua; Zeng, Shuang; He, Xiao-Bing; Fang, Yong-Xiang; Lin, Guo-Zhen; Jing, Zhi-Zhong

    2013-12-01

    In this study, the interactions of classical swine fever virus (CSFV) C-strain and the virulent GSLZ strain with mouse bone marrow-derived immature dendritic cells (BM-imDCs) were investigated for the first time. Both the C-strain and the virulent GSLZ strain could effectively infect and replicate in mouse BM-imDCs. C-strain-infected BM-imDCs showed a greatly enhanced degree of maturation, and could effectively promote the expansion and proliferation of allogeneic naive T cells. The C-strain induced a stronger Th1 response. Infection with the virulent GSLZ strain had no obvious influence on cell maturation or lymphocyte proliferation, and failed to induce any obvious immune response. The results of this study provided initial information for research of the immunologic mechanisms of CSFV using mouse DCs as the model cells.

  5. Mechanism of transfer of functional microRNAs between mouse dendritic cells via exosomes.

    PubMed

    Montecalvo, Angela; Larregina, Adriana T; Shufesky, William J; Stolz, Donna Beer; Sullivan, Mara L G; Karlsson, Jenny M; Baty, Catherine J; Gibson, Gregory A; Erdos, Geza; Wang, Zhiliang; Milosevic, Jadranka; Tkacheva, Olga A; Divito, Sherrie J; Jordan, Rick; Lyons-Weiler, James; Watkins, Simon C; Morelli, Adrian E

    2012-01-19

    Dendritic cells (DCs) are the most potent APCs. Whereas immature DCs down-regulate T-cell responses to induce/maintain immunologic tolerance, mature DCs promote immunity. To amplify their functions, DCs communicate with neighboring DCs through soluble mediators, cell-to-cell contact, and vesicle exchange. Transfer of nanovesicles (< 100 nm) derived from the endocytic pathway (termed exosomes) represents a novel mechanism of DC-to-DC communication. The facts that exosomes contain exosome-shuttle miRNAs and DC functions can be regulated by exogenous miRNAs, suggest that DC-to-DC interactions could be mediated through exosome-shuttle miRNAs, a hypothesis that remains to be tested. Importantly, the mechanism of transfer of exosome-shuttle miRNAs from the exosome lumen to the cytosol of target cells is unknown. Here, we demonstrate that DCs release exosomes with different miRNAs depending on the maturation of the DCs. By visualizing spontaneous transfer of exosomes between DCs, we demonstrate that exosomes fused with the target DCs, the latter followed by release of the exosome content into the DC cytosol. Importantly, exosome-shuttle miRNAs are functional, because they repress target mRNAs of acceptor DCs. Our findings unveil a mechanism of transfer of exosome-shuttle miRNAs between DCs and its role as a means of communication and posttranscriptional regulation between DCs.

  6. Mechanism of transfer of functional microRNAs between mouse dendritic cells via exosomes

    PubMed Central

    Montecalvo, Angela; Larregina, Adriana T.; Shufesky, William J.; Beer Stolz, Donna; Sullivan, Mara L. G.; Karlsson, Jenny M.; Baty, Catherine J.; Gibson, Gregory A.; Erdos, Geza; Wang, Zhiliang; Milosevic, Jadranka; Tkacheva, Olga A.; Divito, Sherrie J.; Jordan, Rick; Lyons-Weiler, James; Watkins, Simon C.

    2012-01-01

    Dendritic cells (DCs) are the most potent APCs. Whereas immature DCs down-regulate T-cell responses to induce/maintain immunologic tolerance, mature DCs promote immunity. To amplify their functions, DCs communicate with neighboring DCs through soluble mediators, cell-to-cell contact, and vesicle exchange. Transfer of nanovesicles (< 100 nm) derived from the endocytic pathway (termed exosomes) represents a novel mechanism of DC-to-DC communication. The facts that exosomes contain exosome-shuttle miRNAs and DC functions can be regulated by exogenous miRNAs, suggest that DC-to-DC interactions could be mediated through exosome-shuttle miRNAs, a hypothesis that remains to be tested. Importantly, the mechanism of transfer of exosome-shuttle miRNAs from the exosome lumen to the cytosol of target cells is unknown. Here, we demonstrate that DCs release exosomes with different miRNAs depending on the maturation of the DCs. By visualizing spontaneous transfer of exosomes between DCs, we demonstrate that exosomes fused with the target DCs, the latter followed by release of the exosome content into the DC cytosol. Importantly, exosome-shuttle miRNAs are functional, because they repress target mRNAs of acceptor DCs. Our findings unveil a mechanism of transfer of exosome-shuttle miRNAs between DCs and its role as a means of communication and posttranscriptional regulation between DCs. PMID:22031862

  7. Ectopic expression of HLA-DO in mouse dendritic cells diminishes MHC class II antigen presentation.

    PubMed

    Fallas, Jennifer L; Tobin, Helen M; Lou, Olivia; Guo, Donglin; Sant'Angelo, Derek B; Denzin, Lisa K

    2004-08-01

    The MHC class II-like molecule HLA-DM (DM) (H-2M in mice) catalyzes the exchange of CLIP for antigenic peptides in the endosomes of APCs. HLA-DO (DO) (H-2O in mice) is another class II-like molecule that is expressed in B cells, but not in other APCs. Studies have shown that DO impairs or modifies the peptide exchange activity of DM. To further evaluate the role of DO in Ag processing and presentation, we generated transgenic mice that expressed the human HLA-DOA and HLA-DOB genes under the control of a dendritic cell (DC)-specific promoter. Our analyses of DCs from these mice showed that as DO levels increased, cell surface levels of A(b)-CLIP also increased while class II-peptide levels decreased. The presentation of some, but not all, exogenous Ags to T cells or T hybridomas was significantly inhibited by DO. Surprisingly, H-2M accumulated in DO-expressing DCs and B cells, suggesting that H-2O/DO prolongs the half-life of H-2M. Overall, our studies showed that DO expression impaired H-2M function, resulting in Ag-specific down-modulation of class II Ag processing and presentation.

  8. The HPV16 E7 Oncoprotein Disrupts Dendritic Cell Function and Induces the Systemic Expansion of CD11b+Gr1+ Cells in a Transgenic Mouse Model

    PubMed Central

    Damian-Morales, Gabriela; Serafín-Higuera, Nicolás; Moreno-Eutimio, Mario Adán; Cortés-Malagón, Enoc M.; Bonilla-Delgado, José; Rodríguez-Uribe, Genaro; Ocadiz-Delgado, Rodolfo; Lambert, Paul F.

    2016-01-01

    Objective. The aim of this study was to analyze the effects of the HPV16 E7 oncoprotein on dendritic cells (DCs) and CD11b+Gr1+ cells using the K14E7 transgenic mouse model. Materials and Methods. The morphology of DCs was analyzed in male mouse skin on epidermal sheets using immunofluorescence and confocal microscopy. Flow cytometry was used to determine the percentages of DCs and CD11b+Gr1+ cells in different tissues and to evaluate the migration of DCs. Results. In the K14E7 mouse model, the morphology of Langerhans cells and the migratory activity of dendritic cells were abnormal. An increase in CD11b+Gr1+ cells was observed in the blood and skin of K14E7 mice, and molecules related to CD11b+Gr1+ chemoattraction (MCP1 and S100A9) were upregulated. Conclusions. These data suggest that the HPV16 E7 oncoprotein impairs the function and morphology of DCs and induces the systemic accumulation of CD11b+Gr1+ cells. PMID:27478837

  9. The Isolation and Enrichment of Large Numbers of Highly Purified Mouse Spleen Dendritic Cell Populations and Their In Vitro Equivalents.

    PubMed

    Vremec, David

    2016-01-01

    Dendritic cells (DCs) form a complex network of cells that initiate and orchestrate immune responses against a vast array of pathogenic challenges. Developmentally and functionally distinct DC subtypes differentially regulate T-cell function. Importantly it is the ability of DC to capture and process antigen, whether from pathogens, vaccines, or self-components, and present it to naive T cells that is the key to their ability to initiate an immune response. Our typical isolation procedure for DC from murine spleen was designed to efficiently extract all DC subtypes, without bias and without alteration to their in vivo phenotype, and involves a short collagenase digestion of the tissue, followed by selection for cells of light density and finally negative selection for DC. The isolation procedure can accommodate DC numbers that have been artificially increased via administration of fms-like tyrosine kinase 3 ligand (Flt3L), either directly through a series of subcutaneous injections or by seeding with an Flt3L secreting murine melanoma. Flt3L may also be added to bone marrow cultures to produce large numbers of in vitro equivalents of the spleen DC subsets. Total DC, or their subsets, may be further purified using immunofluorescent labeling and flow cytometric cell sorting. Cell sorting may be completely bypassed by separating DC subsets using a combination of fluorescent antibody labeling and anti-fluorochrome magnetic beads. Our procedure enables efficient separation of the distinct DC subsets, even in cases where mouse numbers or flow cytometric cell sorting time is limiting.

  10. A microRNA expression atlas of mouse dendritic cell development.

    PubMed

    Johanson, Timothy M; Cmero, Marek; Wettenhall, James; Lew, Andrew M; Zhan, Yifan; Chong, Mark M W

    2015-01-01

    Dendritic cells (DCs) are sentinel cells of the immune system and are essential for inducing a proper immune response. The mechanisms driving the development of DCs are not fully understood. Although the roles of cytokines and transcription factors have been a major focus, there is now substantial interest in the role of microRNAs (miRNAs). miRNAs are small RNAs that regulate gene expression by targeting messenger RNAs for translational repression and ultimately degradation. By means of deep sequencing, we have assembled a comprehensive and quantitative resource of miRNA expression during DC development. We show that mature DCs and their hematopoietic progenitors can be distinguished based on miRNA expression profiles. On the other hand, we show that functionally distinct conventional and plasmacytoid DC subsets are indistinguishable based on miRNA profile. In addition, we identify differences between ex vivo purified conventional DCs and their in vitro Flt3L-generated counterparts. This miRNA expression atlas will provide a valuable resource for the study of miRNAs in DC development and function.

  11. Tumor cells prevent mouse dendritic cell maturation induced by TLR ligands.

    PubMed

    Idoyaga, Juliana; Moreno, José; Bonifaz, Laura

    2007-08-01

    Tumor cells can evade the immune system through several mechanisms, one of which is to block DC maturation. It has been suggested that signaling via Toll-like receptors (TLR) may be involved in the induction of prophylactic anti-cancer immunity and in the treatment of established tumors. In the present study we found that high numbers of tumor cells interfere with BMDC activation induced by the TLR ligands LPS and poly IC. Tumor cells blocked TLR3- and TLR4-mediated induction of MHCII and the co-stimulatory molecules CD40 and CD86, as well as the cytokines IL-12, TNF-alpha and IL-6. Importantly, tumor cells induced inhibitory molecules (B7-DC, B7-H1 and CD80) on spleen DC in vivo and on BMDC, even in the presence of TLR ligands. Moreover, after a long exposure with tumor cells, purified BMDC were unable to respond to a second challenge with TLR ligands. The failure of tumor exposed-BMDC to express co-stimulatory molecules and cytokines in the presence of TLR ligands has implications for the future development of DC-based cancer immune therapies using TLR ligands as adjuvants for the activation of DC.

  12. Effects of Foxp3 gene modified dendritic cells on mouse corneal allograft rejection

    PubMed Central

    Gong, Yu-Bo; Hu, Lian-Na; Liu, Yong; Han, Gen-Cheng; Guo, Hui-Ling; Luo, Ling; Wang, Li-Qiang; Li, Yan; Huang, Yi-Fei

    2015-01-01

    Objective: To investigate the effect of Foxp3 gene modified dendritic cells (Foxp3 + DC) on allogeneic T cells proliferation and to study the effect of Foxp3 + DC on corneal allograft rejection. Methods: Lentivirus-Foxp3 was transfected into DC2.4 cells, as Foxp3 + DC cells. 42 BALB/c mice were randomly divided into: Group A (n = 6), normal group; Group B (n = 12), Group C (n = 12) and Group D (n = 12), allograft groups, were treated with normal saline, DC2.4, Foxp3 + DC by intraperitoneal injection, respectively. Results: Compared with the control group, Foxp3 protein in the Foxp3 + DC cells increased significantly (P < 0.05); the expressions of CD80 and CD86 immunophenotypes of Foxp3 + DC cells decreased significantly (P < 0.05); IL-12 secretion reduced (P < 0.05), but IL-10 secretion was promoted (P < 0.05). The average transplant survival time in Group B was (14.833 ± 1.472) d, and Group C and Group D led to a statistically significant prolongation of transplant survival to (17.667 ± 1.366, 23.000 ± 2.000) d (P < 0.05) respectively. 14 d after transplantation, as compared with Group C and D, the expressions of IFN-γ in grafts markedly increased in Group B. 14 d after transplantation, as compared with Group B, the expressions of Foxp3 mRNA, IDO mRNA in grafts decreased remarkably in Group C and D (P < 0.05); as compared with Group C, the expressions of Foxp3 mRNA, IDO mRNA in grafts decreased remarkably in Group D (P < 0.05). Conclusion: Foxp3 + DC cells reduce the expression of costimulatory factors, reduce the secretion of IL-12, promote IL-10 production and inhibit the stimulation of alloreactive T cell proliferation response capacity. Foxp3 + DC cells play important roles in inhibiting corneal allograft immune response and prolonging graft survival time. PMID:26064298

  13. Chromatin loop organization of the junb locus in mouse dendritic cells

    PubMed Central

    Salem, Tamara; Gomard, Tiphanie; Court, Franck; Moquet-Torcy, Gabriel; Brockly, Frédérique; Forné, Thierry; Piechaczyk, Marc

    2013-01-01

    The junb gene behaves as an immediate early gene in bacterial lipopolysaccharide (LPS)-stimulated dendritic cells (DCs), where its transient transcriptional activation is necessary for the induction of inflammatory cytokines. junb is a short gene and its transcriptional activation by LPS depends on the binding of NF-κB to an enhancer located just downstream of its 3′ UTR. Here, we have addressed the mechanisms underlying the transcriptional hyper-reactivity of junb. Using transfection and pharmacological assays to complement chromatin immunoprecipitation analyses addressing the localization of histones, polymerase II, negative elongation factor (NELF)-, DRB sensitivity-inducing factor (DSIF)- and Positive Transcription Factor b complexes, we demonstrate that junb is a RNA Pol II-paused gene where Pol II is loaded in the transcription start site domain but poorly active. Moreover, High salt-Recovered Sequence, chromosome conformation capture (3C)- and gene transfer experiments show that (i) junb is organized in a nuclear chromatin loop bringing into close spatial proximity the upstream promoter region and the downstream enhancer and (ii) this configuration permits immediate Pol II release on the junb body on binding of LPS-activated NF-κB to the enhancer. Thus, our work unveils a novel topological framework underlying fast junb transcriptional response in DCs. Moreover, it also points to a novel layer of complexity in the modes of action of NF-κB. PMID:23921639

  14. Chromatin loop organization of the junb locus in mouse dendritic cells.

    PubMed

    Salem, Tamara; Gomard, Tiphanie; Court, Franck; Moquet-Torcy, Gabriel; Brockly, Frédérique; Forné, Thierry; Piechaczyk, Marc

    2013-10-01

    The junb gene behaves as an immediate early gene in bacterial lipopolysaccharide (LPS)-stimulated dendritic cells (DCs), where its transient transcriptional activation is necessary for the induction of inflammatory cytokines. junb is a short gene and its transcriptional activation by LPS depends on the binding of NF-κB to an enhancer located just downstream of its 3' UTR. Here, we have addressed the mechanisms underlying the transcriptional hyper-reactivity of junb. Using transfection and pharmacological assays to complement chromatin immunoprecipitation analyses addressing the localization of histones, polymerase II, negative elongation factor (NELF)-, DRB sensitivity-inducing factor (DSIF)- and Positive Transcription Factor b complexes, we demonstrate that junb is a RNA Pol II-paused gene where Pol II is loaded in the transcription start site domain but poorly active. Moreover, High salt-Recovered Sequence, chromosome conformation capture (3C)- and gene transfer experiments show that (i) junb is organized in a nuclear chromatin loop bringing into close spatial proximity the upstream promoter region and the downstream enhancer and (ii) this configuration permits immediate Pol II release on the junb body on binding of LPS-activated NF-κB to the enhancer. Thus, our work unveils a novel topological framework underlying fast junb transcriptional response in DCs. Moreover, it also points to a novel layer of complexity in the modes of action of NF-κB.

  15. A Mouse Model of Adoptive Immunotherapeutic Targeting of Autoimmune Arthritis Using Allo-Tolerogenic Dendritic Cells

    PubMed Central

    Yang, Jie; Yang, Yiming; Ren, Yana; Xie, Rufeng; Zou, Hejian; Fan, Huahua

    2013-01-01

    Objective Tolerogenic dendritic cells (tDCs) are immunosuppressive cells with potent tolerogenic ability and are promising immunotherapeutic tools for treating rheumatoid arthritis (RA). However, it is currently unknown whether allogeneic tDCs (allo-tDCs) induce tolerance in RA, and whether the numbers of adoptively transferred allo-tDCs, or the requirement for pulsing with relevant auto-antigens are important. Methods tDCs were derived from bone marrow precursors of C57BL/B6 mice, which were induced in vitro by GM-CSF, IL-10 and TGF-β1. Collagen-induced arthritis (CIA) was modeled in D1 mice by immunization with type II collagen (CII) to test the therapeutic ability of allo-tDCs against CIA. Clinical and histopathologic scores, arthritic incidence, cytokine and anti-CII antibody secretion, and CD4+Th subsets were analyzed. Results tDCs were characterized in vitro by a stable immature phonotype and a potent immunosuppressive ability. Following adoptive transfer of low doses (5×105) of CII-loaded allo-tDCs, a remarkable anti-arthritic activity, improved clinical scores and histological end-points were found. Serological levels of inflammatory cytokines and anti-CII antibodies were also significantly lower in CIA mice treated with CII-pulsed allo-tDCs as compared with allo-tDCs. Moreover, treatment with allo-tDCs altered the proportion of Treg/Th17 cells. Conclusion These findings suggested that allo-tDCs, especially following antigen loading, reduced the severity of CIA in a dose-dependent manner. The dampening of CIA was associated with modulated cytokine secretion, Treg/Th17 polarization and inhibition of anti-CII secretion. This study highlights the potential therapeutic utility of allo-tDCs in autoimmune arthritis and should facilitate the future design of allo-tDC immunotherapeutic strategies against RA. PMID:24204938

  16. Rapamycin Promotes Mouse 4T1 Tumor Metastasis that Can Be Reversed by a Dendritic Cell-Based Vaccine.

    PubMed

    Lin, Tien-Jen; Liang, Wen-Miin; Hsiao, Pei-Wen; M S, Pradeep; Wei, Wen-Chi; Lin, Hsin-Ting; Yin, Shu-Yi; Yang, Ning-Sun

    2015-01-01

    Suppression of tumor metastasis is a key strategy for successful cancer interventions. Previous studies indicated that rapamycin (sirolimus) may promote tumor regression activity or enhance immune response against tumor targets. However, rapamycin also exhibits immunosuppressant effects and is hence used clinically as an organ transplantation drug. We hypothesized that the immunosuppressive activities of rapamycin might also negatively mediate host immunity, resulting in promotion of tumor metastasis. In this study, the effects of rapamycin and phytochemical shikonin were investigated in vitro and in vivo in a 4T1 mouse mammary tumor model through quantitative assessment of immunogenic cell death (ICD), autophagy, tumor growth and metastasis. Tumor-bearing mice were immunized with test vaccines to monitor their effect on tumor metastasis. We found that intraperitoneal (ip) administration of rapamycin after a tumor-resection surgery drastically increased the metastatic activity of 4T1 tumors. Possible correlation of this finding to human cancers was suggested by epidemiological analysis of data from Taiwan's National Health Insurance Research Database (NHIRD). Since our previous studies showed that modified tumor cell lysate (TCL)-pulsed, dendritic cell (DC)-based cancer vaccines can effectively suppress metastasis in mouse tumor models, we assessed whether such vaccines may help offset this rapamycin-promoted metastasis. We observed that shikonin efficiently induced ICD of 4T1 cells in culture, and DC vaccines pulsed with shikonin-treated TCL (SK-TCL-DC) significantly suppressed rapamycin-enhanced metastasis and Treg cell expansion in test mice. In conclusion, rapamycin treatment in mice (and perhaps in humans) promotes metastasis and the effect may be offset by treatment with a DC-based cancer vaccine.

  17. Dendritic cells serve as a “Trojan horse” for oncolytic adenovirus delivery in the treatment of mouse prostate cancer

    PubMed Central

    Li, Zhao-lun; Liang, Xuan; Li, He-cheng; Wang, Zi-ming; Chong, Tie

    2016-01-01

    Aim: Adenovirus-mediated gene therapy is a novel therapeutic approach for the treatment of cancer, in which replication of the virus itself is the anticancer method. However, the success of this novel therapy is limited due to inefficient delivery of the virus to the target sites. In this study, we used dendritic cells (DCs) as carriers for conditionally replicating adenoviruses (CRAds) in targeting prostate carcinoma (PCa). Methods: Four types of CRAds, including Ad-PC (without PCa-specific promoter and a recombinant human tumor necrosis factor, rmhTNF, sequence), Ad-PC-rmhTNF (without PCa-specific promoter), Ad-PPC-NCS (without an rmhTNF sequence) and Ad-PPC-rmhTNF, were constructed. The androgen-insensitive mouse PCa RM-1 cells were co-cultured with CRAd-loading DCs, and the viability of RM-1 cells was examined using MTT assay. The in vivo effects of CRAd-loading DCs on PCa were evaluated in RM-1 xenograft mouse model. Results: Two PCa-specific CRAds (Ad-PPC-NCS, Ad-PPC-rmhTNF) exhibited more potent suppression on the viability of RM-1 cells in vitro than the PCa-non-specific CRAds (Ad-PC, Ad-PC-rmhTNF). In PCa-bearing mice, intravenous injection of the PCa-specific CRAd-loading DCs significantly inhibited the growth of xenografted tumors, extended the survival time, and induced T-cell activation. Additionally, the rmhTNF-containing CRAds exhibited greater tumor killing ability than CRAds without rmhTNF. Conclusion: DCs may be an effective vector for the delivery of CRAds in the treatment of PCa. PMID:27345628

  18. Stimulatory effect of Echinacea purpurea extract on the trafficking activity of mouse dendritic cells: revealed by genomic and proteomic analyses

    PubMed Central

    2010-01-01

    Background Several Echinacea species have been used as nutraceuticals or botanical drugs for "immunostimulation", but scientific evidence supporting their therapeutic use is still controversial. In this study, a phytocompound mixture extracted from the butanol fraction (BF) of a stem and leaf (S+L) extract of E. purpurea ([BF/S+L/Ep]) containing stringently defined bioactive phytocompounds was obtained using standardized and published procedures. The transcriptomic and proteomic effects of this phytoextract on mouse bone marrow-derived dendritic cells (BMDCs) were analyzed using primary cultures. Results Treatment of BMDCs with [BF/S+L/Ep] did not significantly influence the phenotypic maturation activity of dendritic cells (DCs). Affymetrix DNA microarray and bioinformatics analyses of genes differentially expressed in DCs treated with [BF/S+L/Ep] for 4 or 12 h revealed that the majority of responsive genes were related to cell adhesion or motility (Cdh10, Itga6, Cdh1, Gja1 and Mmp8), or were chemokines (Cxcl2, Cxcl7) or signaling molecules (Nrxn1, Pkce and Acss1). TRANSPATH database analyses of gene expression and related signaling pathways in treated-DCs predicted the JNK, PP2C-α, AKT, ERK1/2 or MAPKAPK pathways as the putative targets of [BF/S+L/Ep]. In parallel, proteomic analysis showed that the expressions of metabolic-, cytoskeleton- or NF-κB signaling-related proteins were regulated by treatment with [BF/S+L/Ep]. In vitro flow cytometry analysis of chemotaxis-related receptors and in vivo cell trafficking assay further showed that DCs treated with [BF/S+L/Ep] were able to migrate more effectively to peripheral lymph node and spleen tissues than DCs treated as control groups. Conclusion Results from this study suggest that [BF/S+L/Ep] modulates DC mobility and related cellular physiology in the mouse immune system. Moreover, the signaling networks and molecules highlighted here are potential targets for nutritional or clinical application of Echinacea or

  19. Human dendritic cells in the severe combined immunodeficiency mouse model: their potentiating role in the allergic reaction.

    PubMed

    Hammad, H; Duez, C; Fahy, O; Tsicopoulos, A; André, C; Wallaert, B; Lebecque, S; Tonnel, A B; Pestel, J

    2000-04-01

    Dendritic cells (DCs) are present in the lungs and airways of healthy and allergic subjects where they are exposed to inhaled antigens. After the uptake of antigens, DCs migrate to lymphoid organs where T cells initiate and control the immune response. The migratory properties of DCs are an essential component of their function but remain unclear in the situation of allergic diseases. To better understand the role of DCs in response to allergens, we first investigated their presence in an original experimental model of allergic asthma: the humanized severe combined immunodeficiency (SCID) mouse reconstituted with peripheral blood mononuclear cells from patients sensitive to Dermatophagoides pteronyssinus (Dpt). Human DCs were detected in lungs of mice developing an inflammatory pulmonary infiltrate and appeared to be mainly located in the alveolar spaces. In a second step, human DCs were generated in vitro from monocytes and injected into naive SCID mice exposed or not exposed to Dpt aerosols. Their migratory behavior was explored, as well as their potential role in modulating the IgE production after exposure to Dpt. After exposure to Dpt, the number of DCs present in airways decreased, while it increased into the spleen and thymus of the mice. The IgE production increased in the presence of DCs as compared with mice not injected with DCs. These results suggest that DCs may play a role in the pulmonary allergic reaction developed in response to Dpt in SCID mice.

  20. Effect of thymoquinone on cytosolic pH and Na+/H+ exchanger activity in mouse dendritic cells.

    PubMed

    Yang, Wenting; Bhandaru, Madhuri; Pasham, Venkanna; Bobbala, Diwakar; Zelenak, Christine; Jilani, Kashif; Rotte, Anand; Lang, Florian

    2012-01-01

    The anti-inflammatory Nigella sativa component thymoquinone compromises the function of dendritic cells (DCs), key players in the regulation of innate and adaptive immunity. DC function is regulated by the Na(+)/H(+) exchanger (NHE), which is stimulated by lipopolysaccharides (LPS) and required for LPS-induced cell swelling, reactive oxygen species (ROS) production, TNF-α release and migration. Here we explored, whether thymoquinone influences NHE activity in DCs. To this end, bone marrow derived mouse DCs were treated with LPS in the absence and presence of thymoquinone (10 μM). Cytosolic pH (pH(i)) was determined from 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fluorescence, NHE activity from the Na(+)-dependent realkalinization following an ammonium pulse, cell volume from forward scatter in FACS analysis, ROS production from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, TNF-α production utilizing ELISA and DC migration with transwell migration assays. As a result, exposure of DCs to LPS (1 μg/ml) led within 4 hours to transient increase of NHE activity. Thymoquinone did not significantly modify cytosolic pH or cellular NHE activity in the absence of LPS, but abrogated the effect of LPS on NHE activity. Accordingly, in the presence of thymoquinone LPS-treatment resulted in cytosolic acidification. LPS further increased forward scatter and ROS formation, effects similarly abrogated by thymoquinone. Again, in the absence of LPS, thymoquinone did not significantly modify ROS formation and cell volume. LPS further triggered TNF-α release and migration, effects again blunted in the presence of thymoquinone. NHE1 inhibitor cariporide (10 μM) blunted LPS induced TNF-α release and migration. The effects of thymoquinone on NHE activity and migration were reversed upon treatment of the cells with t-butyl hydroperoxide (TBOOH, 5 μM). In conclusion, thymoquinone blunts LPS induced NHE activity, cell swelling, oxidative burst

  1. The XC chemokine receptor 1 is a conserved selective marker of mammalian cells homologous to mouse CD8α+ dendritic cells

    PubMed Central

    Crozat, Karine; Guiton, Rachel; Contreras, Vanessa; Feuillet, Vincent; Dutertre, Charles-Antoine; Ventre, Erwan; Vu Manh, Thien-Phong; Baranek, Thomas; Storset, Anne K.; Marvel, Jacqueline; Boudinot, Pierre; Hosmalin, Anne; Schwartz-Cornil, Isabelle

    2010-01-01

    Human BDCA3+ dendritic cells (DCs) were suggested to be homologous to mouse CD8α+ DCs. We demonstrate that human BDCA3+ DCs are more efficient than their BDCA1+ counterparts or plasmacytoid DCs (pDCs) in cross-presenting antigen and activating CD8+ T cells, which is similar to mouse CD8α+ DCs as compared with CD11b+ DCs or pDCs, although with more moderate differences between human DC subsets. Yet, no specific marker was known to be shared between homologous DC subsets across species. We found that XC chemokine receptor 1 (XCR1) is specifically expressed and active in mouse CD8α+, human BDCA3+, and sheep CD26+ DCs and is conserved across species. The mRNA encoding the XCR1 ligand chemokine (C motif) ligand 1 (XCL1) is selectively expressed in natural killer (NK) and CD8+ T lymphocytes at steady-state and is enhanced upon activation. Moreover, the Xcl1 mRNA is selectively expressed at high levels in central memory compared with naive CD8+ T lymphocytes. Finally, XCR1−/− mice have decreased early CD8+ T cell responses to Listeria monocytogenes infection, which is associated with higher bacterial loads early in infection. Therefore, XCR1 constitutes the first conserved specific marker for cell subsets homologous to mouse CD8α+ DCs in higher vertebrates and promotes their ability to activate early CD8+ T cell defenses against an intracellular pathogenic bacteria. PMID:20479118

  2. Mouse ChemR23 is expressed in dendritic cell subsets and macrophages, and mediates an anti-inflammatory activity of chemerin in a lung disease model.

    PubMed

    Luangsay, Souphalone; Wittamer, Valérie; Bondue, Benjamin; De Henau, Olivier; Rouger, Laurie; Brait, Maryse; Franssen, Jean-Denis; de Nadai, Patricia; Huaux, François; Parmentier, Marc

    2009-11-15

    Chemerin is the ligand of the ChemR23 receptor and a chemoattractant factor for human immature dendritic cells (DCs), macrophages, and NK cells. In this study, we characterized the mouse chemerin/ChemR23 system in terms of pharmacology, structure-function, distribution, and in vivo biological properties. Mouse chemerin is synthesized as an inactive precursor (prochemerin) requiring, as in human, the precise processing of its C terminus for generating an agonist of ChemR23. Mouse ChemR23 is highly expressed in immature plasmacytoid DCs and at lower levels in myeloid DCs, macrophages, and NK cells. Mouse prochemerin is expressed in most epithelial cells acting as barriers for pathogens but not in leukocytes. Chemerin promotes calcium mobilization and chemotaxis on DCs and macrophages and these functional responses were abrogated in ChemR23 knockout mice. In a mouse model of acute lung inflammation induced by LPS, chemerin displayed potent anti-inflammatory properties, reducing neutrophil infiltration and inflammatory cytokine release in a ChemR23-dependent manner. ChemR23 knockout mice were unresponsive to chemerin and displayed an increased neutrophil infiltrate following LPS challenge. Altogether, the mouse chemerin/ChemR23 system is structurally and functionally conserved between human and mouse, and mouse can therefore be considered as a good model for studying the anti-inflammatory role of this system in the regulation of immune responses and inflammatory diseases.

  3. The mouse dendritic cell marker CD11c is down-regulated upon cell activation through Toll-like receptor triggering.

    PubMed

    Singh-Jasuja, Harpreet; Thiolat, Allan; Ribon, Matthieu; Boissier, Marie-Christophe; Bessis, Natacha; Rammensee, Hans-Georg; Decker, Patrice

    2013-01-01

    Dendritic cells (DC) play a key role in regulating immune responses and are the best professional antigen-presenting cells. Two major DC populations are defined in part according to cell surface CD11c expression levels. Unexpectedly, we observed that mouse DC strongly down-regulate the typical DC marker CD11c upon activation. To better characterize DC responses, we have analyzed CD11c expression on mouse and human myeloid DC after Toll-like receptor (TLR) triggering. Here we show that mouse bone marrow-derived DC (BMDC) as well as spleen DC down-regulate cell surface CD11c upon activation by TLR3/4/9 agonists. In all cases, full DC activation was reached, as determined by cytokine secretion, cell stimulation in mixed leukocyte reactions (MLR), and CD40/CD86/major histocompatibility complex (MHC) up-regulation. Interestingly, membrane CD11c down-regulation correlated with increased cytoplasmic pools of CD11c. In contrast to the up-regulation of CD40 and MHC class II molecules, lipopolysaccharide (LPS)-induced CD11c down-regulation was MyD88-dependent. Polyinosinic-polycytidylic acid (poly I:C), which does not signal through MyD88, also induced cell surface CD11c down-regulation. Notably, CD11c down-regulation was not observed upon activation of human DC, either through TLR-dependent or -independent cell activation. Thus, activated mouse DC may be transiently CD11c-negative in vivo, hampering the identification of those cells. On the other hand, cell surface CD11c down-regulation may serve as a new activation marker for mouse DC. Copyright © 2012 Elsevier GmbH. All rights reserved.

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

    PubMed

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

    2015-01-01

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

  5. Evaluation of an α synuclein sensitized dendritic cell based vaccine in a transgenic mouse model of Parkinson disease.

    PubMed

    Ugen, Kenneth E; Lin, Xiaoyang; Bai, Ge; Liang, Zhanhua; Cai, Jianfeng; Li, Kunyun; Song, Shijie; Cao, Chuanhai; Sanchez-Ramos, Juan

    2015-01-01

    In order to develop a cell-based vaccine against the Parkinson disease (PD) associated protein α-synuclein (α-Syn) 3 peptides were synthesized based upon predicted B cell epitopes within the full length α-Syn protein sequence. These peptide fragments as well as the full length recombinant human α-Syn (rh- α-Syn) protein were used to sensitize mouse bone marrow-derived dendritic cells (DC) ex vivo, followed by intravenous delivery of these sensitized DCs into transgenic (Tg) mice expressing the human A53T variant of α-Syn. ELISA analysis and testing of behavioral locomotor function by rotometry were performed on all mice after the 5th vaccination as well as just prior to euthanasia. The results indicated that vaccination with peptide sensitized DCs (PSDC) as well as DCs sensitized by rh-α-Syn induced specific anti-α-Syn antibodies in all immunized mice. In terms of rotometry performance, a measure of locomotor activity correlated to brain dopamine levels, mice vaccinated with PSDC or rh- α-Syn sensitized DCs performed significantly better than non-vaccinated Tg control mice during the final assessment (i.e. at 17 months of age) before euthanasia. As well, measurement of levels of brain IL-1α, a cytokine hypothesized to be associated with neuroinflammation, demonstrated that this proinflammatory molecule was significantly reduced in the PSDC and rh- α-Syn sensitized DC vaccinated mice compared to the non-vaccinated Tg control group. Overall, α-Syn antigen-sensitized DC vaccination was effective in generating specific anti- α-Syn antibodies and improved locomotor function without eliciting an apparent general inflammatory response, indicating that this strategy may be a safe and effective treatment for PD.

  6. Induction of specific antitumor immunity in the mouse with the electrofusion product of tumor cells and dendritic cells.

    PubMed

    Siders, William M; Vergilis, Kristin L; Johnson, Carrie; Shields, Jacqueline; Kaplan, Johanne M

    2003-04-01

    Dendritic cells (DCs) are potent antigen-presenting cells capable of inducing primary T-cell responses. Several immunotherapy treatment strategies involve manipulation of DCs, both in vivo and ex vivo, to promote the immunogenic presentation of tumor-associated antigens. In this study, an electrofusion protocol was developed to induce fusion between tumor cells and allogeneic bone marrow-derived DCs. Preimmunization with irradiated electrofusion product was found to provide partial to complete protection from tumor challenge in the murine Renca renal cell carcinoma model and the B16 and M3 melanoma models. Vaccinated survivors developed specific immunological memory and were able to reject a subsequent rechallenge with the same tumor cells but not a syngeneic unrelated tumor line. Antitumor protection in the B16 model was accompanied by the development of a polyclonal cytotoxic T-lymphocyte response against defined melanoma-associated antigens. The therapeutic potential of this type of approach was suggested by the ability of a Renca-DC electrofusion product to induce tumor rejection in a substantial percentage of hosts (60%) bearing pre-established tumor cells. These results indicate that treatment with electrofused tumor cells and allogeneic DCs is capable of inducing a potent antitumor response and could conceivably be applied to a wide range of cancer indications for which tumor-associated antigens have not been identified.

  7. Efficient generation of canine bone marrow-derived dendritic cells.

    PubMed

    Isotani, Mayu; Katsuma, Kensuke; Tamura, Kyoichi; Yamada, Misato; Yagihara, Hiroko; Azakami, Daigo; Ono, Kenichiro; Washizu, Tsukimi; Bonkobara, Makoto

    2006-08-01

    Because of their unsurpassed potency in presenting antigens to naive T cells, dendritic cells are considered to be an important candidate in the development of immunotherapeutic strategies. Despite the high potential of dendritic cell-based immunotherapy, as a so-called dendritic cell vaccination, few clinical approaches using dendritic cell vaccination have been performed in the dog because of very limited information regarding the generation of canine dendritic cells and their functional properties. We therefore established a protocol for the efficient generation of dendritic cells from canine bone marrow cells using recombinant feline granulocyte-macrophage colony-stimulating factor and canine interleukin-4. Dendritic cells were generated efficiently: a yield of 1-9 x 10(6) cells per approximately 0.5 ml of canine bone marrow aspiration was achieved. These dendritic cells showed features shared with mouse and human dendritic cells: dendrite morphology, expression of surface markers MHC class II and CD11c, and up-regulation of molecules related to antigen presentation (MHC class II, B7-1, and B7-2) by activation with lipopolysaccharide. Moreover, the dendritic cells demonstrated phagocytic activity, processing activity of pinocytosed proteins, and activation of allogeneic T cells far more potent than that by macrophages. Our findings suggest that the bone marrow-derived dendritic cells are functional for the capturing and processing of antigens and the initiation of T cell responses.

  8. Human dendritic cell subsets

    PubMed Central

    Collin, Matthew; McGovern, Naomi; Haniffa, Muzlifah

    2013-01-01

    Summary Dendritic cells are highly adapted to their role of presenting antigen and directing immune responses. Developmental studies indicate that DCs originate independently from monocytes and tissue macrophages. Emerging evidence also suggests that distinct subsets of DCs have intrinsic differences that lead to functional specialisation in the generation of immunity. Comparative studies are now allowing many of these properties to be more fully understood in the context of human immunology. PMID:23621371

  9. Transcriptional regulation of the mouse CD11c promoter by AP-1 complex with JunD and Fra2 in dendritic cells.

    PubMed

    Hara, Mutsuko; Yokoyama, Hokuto; Fukuyama, Kanako; Kitamura, Nao; Shimokawa, Naomi; Maeda, Keiko; Kanada, Shunsuke; Ito, Tomonobu; Usui, Yoshihiko; Ogawa, Hideoki; Okumura, Ko; Nishiyama, Makoto; Nishiyama, Chiharu

    2013-03-01

    CD11c, a member of the β(2) integrin family of adhesion molecule, is expressed on the surface of myeloid lineages and activated lymphoid cells and forms a heterodimeric receptor with CD18. We analyzed the mouse CD11c promoter structure to elucidate the transcriptional regulation in dendritic cells (DCs). By reporter assay, the -84/-65 region was identified to be essential for activity of the mouse CD11c promoter in the mouse bone marrow-derived (BM) DCs and monocyte cell line RAW264.7. An electrophoretic mobility shift assay using a number of antibodies against transcription factors revealed that the target region was recognized by a complex including JunD and Fra2, which are transcription factors belonging to the AP-1 family. The direct interaction of JunD and Fra2 with the CD11c promoter was further confirmed by a chromatin immunoprecipitation assay using CD11c-positive cells purified from BMDCs. Finally, mouse JunD and/or Fra2 siRNA was introduced into BMDCs to evaluate the involvement of these factors against CD11c transcription and found that Fra2 siRNA reduced cell surface expression level of CD11c. These results indicate that AP-1 composed with JunD and Fra2 protein plays a primary role in enhancing the transcription level of the CD11c gene in DC. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Mucosal and systemic anti-HIV immunity controlled by A20 in mouse dendritic cells.

    PubMed

    Hong, Bangxing; Song, Xiao-Tong; Rollins, Lisa; Berry, Lindsey; Huang, Xue F; Chen, Si-Yi

    2011-02-01

    Both mucosal and systemic immune responses are required for preventing or containing HIV transmission and chronic infection. However, currently described vaccination approaches are largely ineffective in inducing both mucosal and systemic responses. In this study, we found that the ubiquitin-editing enzyme A20--an inducible feedback inhibitor of the TNFR, RIG-I, and TLR signaling pathways that broadly controls the maturation, cytokine production, and immunostimulatory potency of DCs--restricted systemically immunized DCs to induce both robust mucosal and systemic HIV-specific cellular and humoral responses. Mechanistic studies revealed that A20 regulated DC production of retinoic acid and proinflammatory cytokines, inhibiting the expression of gut-homing receptors on T and B cells. Furthermore, A20-silenced, hyperactivated DCs exhibited an enhanced homing capacity to draining and gut-associated lymphoid tissues (GALTs) after systemic administration. Thus, this study provides insights into the role of A20 in innate immunity. This work may allow the development of an efficient HIV vaccination strategy that is capable of inducing both robust systemic and mucosal anti-HIV cellular and humoral responses.

  11. Mucosal and systemic anti-HIV immunity controlled by A20 in mouse dendritic cells

    PubMed Central

    Hong, Bangxing; Song, Xiao-Tong; Rollins, Lisa; Berry, Lindsey; Huang, Xue F.; Chen, Si-Yi

    2011-01-01

    Both mucosal and systemic immune responses are required for preventing or containing HIV transmission and chronic infection. However, currently described vaccination approaches are largely ineffective in inducing both mucosal and systemic responses. In this study, we found that the ubiquitin-editing enzyme A20 — an inducible feedback inhibitor of the TNFR, RIG-I, and TLR signaling pathways that broadly controls the maturation, cytokine production, and immunostimulatory potency of DCs — restricted systemically immunized DCs to induce both robust mucosal and systemic HIV-specific cellular and humoral responses. Mechanistic studies revealed that A20 regulated DC production of retinoic acid and proinflammatory cytokines, inhibiting the expression of gut-homing receptors on T and B cells. Furthermore, A20-silenced, hyperactivated DCs exhibited an enhanced homing capacity to draining and gut-associated lymphoid tissues (GALTs) after systemic administration. Thus, this study provides insights into the role of A20 in innate immunity. This work may allow the development of an efficient HIV vaccination strategy that is capable of inducing both robust systemic and mucosal anti-HIV cellular and humoral responses. PMID:21206085

  12. Characterization of chicken dendritic cell markers

    USDA-ARS?s Scientific Manuscript database

    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 ...

  13. [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.

  14. Endostatin enhances antitumor effect of tumor antigen-pulsed dendritic cell therapy in mouse xenograft model of lung carcinoma

    PubMed Central

    Liang, Jing; Liu, Xiaolin; Xie, Qi; Chen, Guoling; Li, Xingyu; Jia, Yanrui; Yin, Beibei; Qu, Xun; Li, Yan

    2016-01-01

    Objective To investigate the antitumor effect of endostatin combined with tumor antigen-pulsed dendritic cell (DC)-T cell therapy on lung cancer. Methods Transplanted Lewis lung cancer (LLC) models of C57BL/6 mice were established by subcutaneous injection of LLC cells in left extremity axillary. Tumor antigen-pulsed DC-T cells from spleen cells and bone of mice were cultured in vitro. Tumor-bearing mice were randomly divided into three groups, including DC-T+endostatin group, DC-T group, and phosphate-buffered saline (PBS) control group. Microvessel density (MVD) of tumor tissue in tumor-bearing mice was determined by immunohistochemistry (IHC). The expressions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) were determined by Western blotting and IHC staining. The proportions of CD8+ T cells, mature dendritic cells (mDC), tumor-associated macrophages [TAM (M1/M2)], and myeloid-derived suppressor cells (MDSC) in suspended cells of tumor tissue were determined by flow cytometry. The expressions of interleukin (IL)-6, IL-10, IL-17, transforming growth factor-β (TGF-β) and interferon-γ (IFN-γ) in suspended cells of tumor tissue were detected by enzyme-linked immune sorbent assay (ELISA). Results DC-T cells combined with endostatin remarkably suppressed tumor growth. MVD of mice in DC-T+endostatin group was significantly lower than that of the control group and DC-T monotherapy group. The expressions of VEGF, IL-6 and IL-17 in tumors were markedly decreased, but IFN-γ and HIF-1α increased after treating with DC-T cells combined with endostatin, compared to control group and DC-T group. In the DC-T+endostatin group, the proportions of MDSC and TAM (M2 type) were significantly decreased, mDC and TAM (M1 type) were up-regulated, and CD8+ T cells were recruited to infiltrate tumors, in contrast to PBS control and DC-T monotherapy. DC-T cells combined with endostatin potently reduced the expressions of IL-6, IL-10, TGF-β and

  15. Graft-infiltrating PD-L1(hi) cross-dressed dendritic cells regulate anti-donor T cell responses in mouse liver transplant tolerance.

    PubMed

    Ono, Yoshihiro; Perez-Gutierrez, Angelica; Nakao, Toshimasa; Dai, Helong; Camirand, Geoffrey; Yoshida, Osamu; Yokota, Shinichiro; Stolz, Donna Beer; Ross, Mark A; Morelli, Adrian E; Geller, David A; Thomson, Angus W

    2017-09-16

    While a key role of cross-dressing has been established in immunity to viral infection and more recently in the instigation of transplant rejection, its role in tolerance is unclear. Here, we investigated the role of intra-graft dendritic cells (DC) and cross-dressing in mouse major histocompatibility complex (MHC)-mismatched liver transplant tolerance that occurs without therapeutic immunosuppression. While donor interstitial DC diminished rapidly following transplantation, they were replaced in the liver by host DC that peaked on postoperative day (POD) 7 and persisted indefinitely. About 60% of these recipient DC displayed donor MHC class I, indicating cross-dressing. By contrast, only a very minor fraction (0-2%) of cross-dressed DC (CD-DC) was evident in the spleen. CD-DC sorted from liver grafts expressed much higher levels of T cell inhibitory programed death ligand 1 (PD-L1) and high levels of IL-10 compared with non CD-DC (nCD-DC) isolated from the graft. Concomitantly, high incidences of programed death protein 1 (PD-1)(hi) T cell immunoglobulin and mucin domain containing-3 (TIM-3)(+) exhausted graft-infiltrating CD8(+) T cells were observed. Importantly, unlike nCD-DC, the CD-DC failed to stimulate proliferation of allogeneic T cells but markedly suppressed anti-donor host T cell proliferation. CD-DC were much less evident in allografts from DNAX-activating protein of 12kDa (DAP12)(-/-) donors that were rejected acutely. These findings suggest that graft-infiltrating PD-L1(hi) CD-DC may play a key role in the regulation of alloimmunity and in the induction of liver transplant tolerance. This article is protected by copyright. All rights reserved. © 2017 by the American Association for the Study of Liver Diseases.

  16. Can dendritic cells see light?

    NASA Astrophysics Data System (ADS)

    Chen, Aaron C.-H.; Huang, Ying-Ying; Sharma, Sulbha K.; Hamblin, Michael R.

    2010-02-01

    There are many reports showing that low-level light/laser therapy (LLLT) can enhance wound healing, upregulate cell proliferation and has anti-apoptotic effects by activating intracellular protective genes. In the field of immune response study, it is not known with any certainty whether light/laser is proinflammatory or anti-inflammatory. Increasingly in recent times dendritic cells have been found to play an important role in inflammation and the immunological response. In this study, we try to look at the impact of low level near infrared light (810-nm) on murine bone-marrow derived dendritic cells. Changes in surface markers, including MHC II, CD80 and CD11c and the secretion of interleukins induced by light may provide additional evidence to reveal the mystery of how light affects the maturation of dendritic cells as well how these light-induced mature dendritic cells would affect the activation of adaptive immune response.

  17. The human cancer antigen mesothelin is more efficiently presented to the mouse immune system when targeted to the DEC-205/CD205 receptor on dendritic cells

    PubMed Central

    Wang, Bei; Kuroiwa, Janelle M.Y.; He, Li-Zhen; Charalambous, Anna; Keler, Tibor; Steinman, Ralph M.

    2010-01-01

    To develop a tumor vaccine directly targeting tumor antigen to dendritic cells in situ, we engineered human mesothelin (MSLN) into an antibody specific for mouse DEC-205, a receptor for antigen presentation. We then characterized both T cell and humoral responses to human MSLN and compared immunizing efficacy of DEC-205-targeted MSLN to nontargeted protein after a single dose immunization. Targeting human MSLN to DEC-205 receptor induced stronger CD4+ T cell responses compared to high doses of mesothelin protein. ∼0.5% CD4+ T cells were primed to produce IFN-γ, TNF-α and IL-2 via intracellular cytokine staining, and the T cells also could proliferate rapidly. The immune response exhibited breadth because the primed CD4+ T cells responded to at least three epitopes in the H-2b background. Targeting MSLN protein to DEC-205 receptor also resulted in cross-presentation to CD8+ T cells. Antibody responses against human MSLN were also detected in serum from primed mice by ELISA assays. In summary, targeting of MSLN to DEC-205 improves the induction of CD4+ and CD8+ T cell immunity accompanied by an antibody response. DEC-205-targeting could be valuable to enhance immunity to MSLN in the setting of cancers where this nonmutated protein is expressed. PMID:19769731

  18. 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.

  19. Reconsideration of macrophage and dendritic cell classification.

    PubMed

    Kadowaki, Takeshi; Shimada, Misato; Inagawa, Hiroyuki; Kohchi, Chie; Hirashima, Mitsuomi; Soma, Gen-Ichiro

    2012-06-01

    It is well known that the activation of innate immune cells, especially antigen-presenting cells such as macrophages and dendritic cells, can ameliorate or exacerbate various diseases, including cancer. Currently, the macrophages and dendritic cells are categorized into several groups by their cell surface and intracellular molecules. However, the detailed classification of the differences between macrophages and dendritic cells has still not been established. Here, we summarized and reviewed the previous studies on the classification of macrophages and dendritic cells. In addition, the previous classification of monocytes, macrophages and dendritic cells is discussed based on our findings of macrophage activation, which has both conventional and plasmacytoid dendritic cell phenotype.

  20. MicroRNA-Mediated Down-Regulation of M-CSF Receptor Contributes to Maturation of Mouse Monocyte-Derived Dendritic Cells

    PubMed Central

    Riepsaame, Joey; van Oudenaren, Adri; den Broeder, Berlinda J. H.; van IJcken, Wilfred F. J.; Pothof, Joris; Leenen, Pieter J. M.

    2013-01-01

    Dendritic cell (DC) maturation is a tightly regulated process that requires coordinated and timed developmental cues. Here we investigate whether microRNAs are involved in this process. We identify microRNAs in mouse GM-CSF-generated, monocyte-related DC (GM-DC) that are differentially expressed during both spontaneous and LPS-induced maturation and characterize M-CSF receptor (M-CSFR), encoded by the Csf1r gene, as a key target for microRNA-mediated regulation in the final step toward mature DC. MicroRNA-22, -34a, and -155 are up-regulated in mature MHCIIhi CD86hi DC and mediate Csf1r mRNA and protein down-regulation. Experimental inhibition of Csf1r-targeting microRNAs in vitro results not only in sustained high level M-CSFR protein expression but also in impaired DC maturation upon stimulation by LPS. Accordingly, over-expression of Csf1r in GM-DC inhibits terminal differentiation. Taken together, these results show that developmentally regulated microRNAs control Csf1r expression, supplementing previously identified mechanisms that regulate its transcription and protein surface expression. Furthermore, our data indicate a novel function for Csf1r in mouse monocyte-derived DC, showing that down-regulation of M-CSFR expression is essential for final DC maturation. PMID:24198819

  1. MicroRNA-Mediated Down-Regulation of M-CSF Receptor Contributes to Maturation of Mouse Monocyte-Derived Dendritic Cells.

    PubMed

    Riepsaame, Joey; van Oudenaren, Adri; den Broeder, Berlinda J H; van Ijcken, Wilfred F J; Pothof, Joris; Leenen, Pieter J M

    2013-01-01

    Dendritic cell (DC) maturation is a tightly regulated process that requires coordinated and timed developmental cues. Here we investigate whether microRNAs are involved in this process. We identify microRNAs in mouse GM-CSF-generated, monocyte-related DC (GM-DC) that are differentially expressed during both spontaneous and LPS-induced maturation and characterize M-CSF receptor (M-CSFR), encoded by the Csf1r gene, as a key target for microRNA-mediated regulation in the final step toward mature DC. MicroRNA-22, -34a, and -155 are up-regulated in mature MHCII(hi) CD86(hi) DC and mediate Csf1r mRNA and protein down-regulation. Experimental inhibition of Csf1r-targeting microRNAs in vitro results not only in sustained high level M-CSFR protein expression but also in impaired DC maturation upon stimulation by LPS. Accordingly, over-expression of Csf1r in GM-DC inhibits terminal differentiation. Taken together, these results show that developmentally regulated microRNAs control Csf1r expression, supplementing previously identified mechanisms that regulate its transcription and protein surface expression. Furthermore, our data indicate a novel function for Csf1r in mouse monocyte-derived DC, showing that down-regulation of M-CSFR expression is essential for final DC maturation.

  2. Long-Term Depletion of Conventional Dendritic Cells Cannot Be Maintained in an Atherosclerotic Zbtb46-DTR Mouse Model

    PubMed Central

    Cools, Nathalie; Grootaert, Mandy O. J.; de Bakker, Flore; Van Brussel, Ilse; Wouters, An; De Meyer, Guido R. Y.; De Winter, Benedicte Y.; Schrijvers, Dorien M.

    2017-01-01

    Background and aims Increased evidence suggests a pro-atherogenic role for conventional dendritic cells (cDC). However, due to the lack of an exclusive marker for cDC, their exact contribution to atherosclerosis remains elusive. Recently, a unique transcription factor was described for cDC, namely Zbtb46, enabling us to selectively target this cell type in mice. Methods Low-density lipoprotein receptor-deficient (Ldlr-/-) mice were transplanted with bone marrow from Zbtb46-diphtheria toxin receptor (DTR) transgenic mice following total body irradiation. Zbtb46-DTR→Ldlr-/- chimeras were fed a Western-type diet for 18 weeks while cDC were depleted by administering diphtheria toxin (DT). Results Although we confirmed efficient direct induction of cDC death in vitro and in vivo upon DT treatment of Zbtb46-DTR mice, advanced atherosclerotic plaque size and composition was not altered. Surprisingly, however, analysis of Zbtb46-DTR→Ldlr-/- chimeras showed that depletion of cDC was not sustained following 18 weeks of DT treatment. In contrast, high levels of anti-DT antibodies were detected. Conclusions Because of the observed generation of anti-DT antibodies and consequently the partial depletion of cDC, no clear decision can be taken on the role of cDC in atherosclerosis. Our results underline the unsuitability of Zbtb46-DTR→Ldlr-/- mice for studying the involvement of cDC in maintaining the disease process of atherosclerosis, as well as of other chronic inflammatory diseases. PMID:28060909

  3. Acetylcorynoline Impairs the Maturation of Mouse Bone Marrow-Derived Dendritic Cells via Suppression of IκB Kinase and Mitogen-Activated Protein Kinase Activities

    PubMed Central

    Fu, Ru-Huei; Wang, Yu-Chi; Liu, Shih-Ping; Chu, Ching-Liang; Tsai, Rong-Tzong; Ho, Yu-Chen; Chang, Wen-Lin; Chiu, Shao-Chih; Harn, Horng-Jyh; Shyu, Woei-Cherng; Lin, Shinn-Zong

    2013-01-01

    Background Dendritic cells (DCs) are major modulators in the immune system. One active field of research is the manipulation of DCs as pharmacological targets to screen novel biological modifiers for the treatment of inflammatory and autoimmune disorders. Acetylcorynoline is the major alkaloid component derived from Corydalis bungeana herbs. We assessed the capability of acetylcorynoline to regulate lipopolysaccharide (LPS)-stimulated activation of mouse bone marrow-derived DCs. Methodology/Principal Findings Our experimental data showed that treatment with up to 20 µM acetylcorynoline does not cause cytotoxicity in cells. Acetylcorynoline significantly inhibited the secretion of tumor necrosis factor-α, interleukin-6, and interleukin-12p70 by LPS-stimulated DCs. The expression of LPS-induced major histocompatibility complex class II, CD40, and CD86 on DCs was also decreased by acetylcorynoline, and the endocytic capacity of LPS-stimulated DCs was restored by acetylcorynoline. In addition, LPS-stimulated DC-elicited allogeneic T-cell proliferation was blocked by acetylcorynoline, and the migratory ability of LPS-stimulated DCs was reduced by acetylcorynoline. Moreover, acetylcorynoline significantly inhibits LPS-induced activation of IκB kinase and mitogen-activated protein kinase. Importantly, administration of acetylcorynoline significantly attenuates 2,4-dinitro-1-fluorobenzene-induced delayed-type hypersensitivity. Conclusions/Significance Acetylcorynoline may be one of the potent immunosuppressive agents through the blockage of DC maturation and function. PMID:23472193

  4. Deficiency of Lymph Node-Resident Dendritic Cells (DCs) and Dysregulation of DC Chemoattractants in a Malnourished Mouse Model of Leishmania donovani Infection

    PubMed Central

    Ibrahim, Marwa K.; Barnes, Jeffrey L.; Osorio, E. Yaneth; Anstead, Gregory M.; Jimenez, Fabio; Osterholzer, John J.; Travi, Bruno L.; Ahuja, Seema S.; White, A. Clinton

    2014-01-01

    Malnutrition is thought to contribute to more than one-third of all childhood deaths via increased susceptibility to infection. Malnutrition is a significant risk factor for the development of visceral leishmaniasis, which results from skin inoculation of the intracellular protozoan Leishmania donovani. We previously established a murine model of childhood malnutrition and found that malnutrition decreased the lymph node barrier function and increased the early dissemination of L. donovani. In the present study, we found reduced numbers of resident dendritic cells (conventional and monocyte derived) but not migratory dermal dendritic cells in the skin-draining lymph nodes of L. donovani-infected malnourished mice. Expression of chemokines and their receptors involved in trafficking of dendritic cells and their progenitors to the lymph nodes was dysregulated. C-C chemokine receptor type 2 (CCR2) and its ligands (CCL2 and CCL7) were reduced in the lymph nodes of infected malnourished mice, as were CCR2-bearing monocytes/macrophages and monocyte-derived dendritic cells. However, CCR7 and its ligands (CCL19 and CCL21) were increased in the lymph node and CCR7 was increased in lymph node macrophages and dendritic cells. CCR2-deficient mice recapitulated the profound reduction in the number of resident (but not migratory dermal) dendritic cells in the lymph node but showed no alteration in the expression of CCL19 and CCL21. Collectively, these results suggest that the malnutrition-related reduction in the lymph node barrier to dissemination of L. donovani is related to insufficient numbers of lymph node-resident but not migratory dermal dendritic cells. This is likely driven by the altered activity of the CCR2 and CCR7 chemoattractant pathways. PMID:24818662

  5. Deficiency of lymph node-resident dendritic cells (DCs) and dysregulation of DC chemoattractants in a malnourished mouse model of Leishmania donovani infection.

    PubMed

    Ibrahim, Marwa K; Barnes, Jeffrey L; Osorio, E Yaneth; Anstead, Gregory M; Jimenez, Fabio; Osterholzer, John J; Travi, Bruno L; Ahuja, Seema S; White, A Clinton; Melby, Peter C

    2014-08-01

    Malnutrition is thought to contribute to more than one-third of all childhood deaths via increased susceptibility to infection. Malnutrition is a significant risk factor for the development of visceral leishmaniasis, which results from skin inoculation of the intracellular protozoan Leishmania donovani. We previously established a murine model of childhood malnutrition and found that malnutrition decreased the lymph node barrier function and increased the early dissemination of L. donovani. In the present study, we found reduced numbers of resident dendritic cells (conventional and monocyte derived) but not migratory dermal dendritic cells in the skin-draining lymph nodes of L. donovani-infected malnourished mice. Expression of chemokines and their receptors involved in trafficking of dendritic cells and their progenitors to the lymph nodes was dysregulated. C-C chemokine receptor type 2 (CCR2) and its ligands (CCL2 and CCL7) were reduced in the lymph nodes of infected malnourished mice, as were CCR2-bearing monocytes/macrophages and monocyte-derived dendritic cells. However, CCR7 and its ligands (CCL19 and CCL21) were increased in the lymph node and CCR7 was increased in lymph node macrophages and dendritic cells. CCR2-deficient mice recapitulated the profound reduction in the number of resident (but not migratory dermal) dendritic cells in the lymph node but showed no alteration in the expression of CCL19 and CCL21. Collectively, these results suggest that the malnutrition-related reduction in the lymph node barrier to dissemination of L. donovani is related to insufficient numbers of lymph node-resident but not migratory dermal dendritic cells. This is likely driven by the altered activity of the CCR2 and CCR7 chemoattractant pathways.

  6. 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.

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

    PubMed

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

    2009-03-01

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

  8. Synapse Loss and Dendrite Remodeling in a Mouse Model of Glaucoma.

    PubMed

    Berry, Ryan H; Qu, Juan; John, Simon W M; Howell, Gareth R; Jakobs, Tatjana C

    2015-01-01

    It has been hypothesized that synaptic pruning precedes retinal ganglion cell degeneration in glaucoma, causing early dysfunction to retinal ganglion cells. To begin to assess this, we studied the excitatory synaptic inputs to individual ganglion cells in normal mouse retinas and in retinas with ganglion cell degeneration from glaucoma (DBA/2J), or following an optic nerve crush. Excitatory synapses were labeled by AAV2-mediated transfection of ganglion cells with PSD-95-GFP. After both insults the linear density of synaptic inputs to ganglion cells decreased. In parallel, the dendritic arbors lost complexity. We did not observe any cells that had lost dendritic synaptic input while preserving a normal or near-normal morphology. Within the temporal limits of these observations, dendritic remodeling and synapse pruning thus appear to occur near-simultaneously.

  9. Running per se stimulates the dendritic arbor of newborn dentate granule cells in mouse hippocampus in a duration-dependent manner.

    PubMed

    Dostes, Sandrine; Dubreucq, Sarah; Ladevèze, Elodie; Marsicano, Giovanni; Abrous, Djoher N; Chaouloff, Francis; Koehl, Muriel

    2016-03-01

    Laboratory rodents provided chronic unlimited access to running wheels display increased neurogenesis in the hippocampal dentate gyrus. In addition, recent studies indicate that such an access to wheels stimulates dendritic arborization in newly formed neurons. However, (i) the presence of the running wheel in the housing environment might also bear intrinsic influences on the number and shape of new neurons and (ii) the dendritic arborization of new neurons might be insensitive to moderate daily running activity (i.e., several hours). In keeping with these uncertainties, we have examined neurogenesis and dendritic arborization in newly formed granular cells in adult C57Bl/6N male mice housed for 3 weeks under standard conditions, with a locked wheel, with a running wheel set free 3 h/day, or with a running wheel set permanently free. The results indicate that the presence of a blocked wheel in the home cage increased cell proliferation, but not the number of new neurons while running increased in a duration-dependent manner the number of newborn neurons, as assessed by DCX labeling. Morphological analyses of the dendritic tree of newborn neurons, as identified by BrdU-DCX co-staining, revealed that although the presence of the wheel stimulated their dendritic architecture, the amplitude of this effect was lower than that elicited by running activity, and was found to be running duration-dependent.

  10. Inhibition of dendrite formation in mouse melanocytes transiently transfected with antisense DNA to myosin Va

    PubMed Central

    EDGAR, ALASDAIR J.; BENNETT, JONATHAN P.

    1999-01-01

    In mice a molecular motor of the myosin V class (designated myosin Va) is known to be the product of the dilute locus, where a mutation prevents melanosome transport in melanocytes. There is conflicting evidence about whether it has a role in dendrite outgrowth. We investigated its role by transiently transfecting antisense oligonucleotides to inhibit its expression in a melanocyte cell line. We demonstrated mRNA and protein expression of myosin Va in 3 mouse melanocyte lines and 1 human melanoma cell line, using RT-PCR and immunoblotting. Two splice variants were found in human cells whilst only the longer transcript, containing an additional exon, was present in mouse melanocyte lines. The shorter variant was detected in other mouse tissues. Myosin Va protein levels were similar in 3 melanocyte lines with differing amounts of pigmentation, indicating that expression of myosin Va is not tightly coupled to expression of melanin. Immunocytochemistry showed 2 types of myosin Va localisation. A punctate pattern of staining concentrated in the perinuclear region was indicative of organelle association, and the observation of occasional linear punctate staining aligned with F-actin bundles supported the idea that myosin Va has a role in transporting melanosomes along actin filaments. Staining was also intense at tips of dendrites and at sites of dendrite-cell contact, consistent with a possible role in dendrite growth. Transient transfection of antisense phosphorothioate oligodeoxynucleotides targeted against myosin Va mRNA reduced expression of myosin Va protein in cultured mouse melan-a melanocytes by over 70% 20 h after transfection whereas a control (shuffled sequence) oligonucleotide did not. Upon trypsinisation and replating these cells the capacity of the transfected cells to extend new dendrites was reduced in the cells containing the specific antisense oligonucleotides but unaffected by the control oligonucleotide. Image analysis confirmed that the effect of

  11. 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

  12. Immune-modulating effects in mouse dendritic cells of lactobacilli and bifidobacteria isolated from individuals following omnivorous, vegetarian and vegan diets.

    PubMed

    Luongo, Diomira; Treppiccione, Lucia; Sorrentino, Alida; Ferrocino, Ilario; Turroni, Silvia; Gatti, Monica; Di Cagno, Raffaella; Sanz, Yolanda; Rossi, Mauro

    2017-09-01

    Lactobacilli and bifidobacteria play a primary role in modulation of gut immunity. By considering that microbiota composition depends on various factors, including diet, we asked whether functional differences could characterize faecal populations of lactobacilli and bifidobacteria isolated from individuals with different dietary habits. 155 healthy volunteers who followed omnivorous, ovo-lacto-vegetarian or vegan diets were recruited at four Italian centres (Turin, Parma, Bologna and Bari). Faecal samples were collected; lactobacilli and bifidobacteria were isolated on selective media and their immunomodulatory activity was tested in mouse dendritic cells (DCs). Pre-incubation with lactobacilli increased LPS-induced expression of the maturation markers CD80 and CD86, whereas pre-incubation with bifidobacteria decreased such expression. Analysis of the cytokine profile indicated that strains of both genera induced down-regulation of IL-12 and up-regulation of IL-10, whereas expression of TNF-α was not modulated. Notably, analysis of anti-inflammatory potential (IL-10/IL-12 ratio) showed that lactobacilli evoked a greater anti-inflammatory effect than did bifidobacteria in the omnivorous group (P<0.05). We also found significantly reduced anti-inflammatory potential in the bacterial strains isolated from Bari's volunteers in comparison with those from the cognate groups from the other centres. In conclusion, lactobacilli and bifidobacteria showed a genus-specific ability of modulating in vitro innate immunity associated with a specific dietary habit. Furthermore, the geographical area had a significant impact on the anti-inflammatory potential of some components of faecal microbiota. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Dendritic cell subsets digested: RNA sensing makes the difference!

    PubMed

    Buschow, Sonja I; Figdor, Carl G

    2010-02-26

    In this issue of Immunity, Luber et al. (2010) report a comprehensive quantitative proteome of in vivo mouse spleen dendritic cell (DC) subsets: a data set of encyclopedic value already revealing that DC subsets exploit different RNA sensors for virus recognition. Copyright 2010 Elsevier Inc. All rights reserved.

  14. 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.

  15. Functional specializations of intestinal dendritic cell and macrophage subsets that control Th17 and regulatory T cell responses are dependent on the T cell/APC ratio, source of mouse strain, and regional localization.

    PubMed

    Denning, Timothy L; Norris, Brian A; Medina-Contreras, Oscar; Manicassamy, Santhakumar; Geem, Duke; Madan, Rajat; Karp, Christopher L; Pulendran, Bali

    2011-07-15

    Although several subsets of intestinal APCs have been described, there has been no systematic evaluation of their phenotypes, functions, and regional localization to date. In this article, we used 10-color flow cytometry to define the major APC subsets in the small and large intestine lamina propria. Lamina propria APCs could be subdivided into CD11c(+)CD11b(-), CD11c(+)CD11b(+), and CD11c(dull)CD11b(+) subsets. CD11c(+)CD11b(-) cells were largely CD103(+)F4/80(-) dendritic cells (DCs), whereas the CD11c(+)CD11b(+) subset comprised CD11c(+)CD11b(+)CD103(+)F4/80(-) DCs and CD11c(+)CD11b(+)CD103(-)F4/80(+) macrophage-like cells. The majority of CD11c(dull)CD11b(+) cells were CD103(-)F4/80(+) macrophages. Although macrophages were more efficient at inducing Foxp3(+) regulatory T (T(reg)) cells than DCs, at higher T cell/APC ratios, all of the DC subsets efficiently induced Foxp3(+) T(reg) cells. In contrast, only CD11c(+)CD11b(+)CD103(+) DCs efficiently induced Th17 cells. Consistent with this, the regional distribution of CD11c(+)CD11b(+)CD103(+) DCs correlated with that of Th17 cells, with duodenum > jejunum > ileum > colon. Conversely, CD11c(+)CD11b(-)CD103(+) DCs, macrophages, and Foxp3(+) T(reg) cells were most abundant in the colon and scarce in the duodenum. Importantly, however, the ability of DC and macrophage subsets to induce Foxp3(+) T(reg) cells versus Th17 cells was strikingly dependent on the source of the mouse strain. Thus, DCs from C57BL/6 mice from Charles River Laboratories (that have segmented filamentous bacteria, which induce robust levels of Th17 cells in situ) were more efficient at inducing Th17 cells and less efficient at inducing Foxp3(+) T(reg) cells than DCs from B6 mice from The Jackson Laboratory. Thus, the functional specializations of APC subsets in the intestine are dependent on the T cell/APC ratio, regional localization, and source of the mouse strain.

  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. Mass spectrometry analysis and quantitation of peptides presented on the MHC II molecules of mouse spleen dendritic cells

    PubMed Central

    Bozzacco, Leonia; Yu, Haiqiang; Zebroski, Henry A.; Dengjel, Jörn; Deng, Haiteng; Mojsov, Svetlana; Steinman, Ralph M.

    2011-01-01

    Major histocompatibility complex class II (MHC II) molecules are expressed on the surface of antigen presenting cells and display short bound peptide fragments derived from self and nonself antigens. These peptide-MHC complexes function to maintain immunological tolerance in the case of self antigens and initiate the CD4+ T cell response in the case of foreign proteins. Here we report the application of LC-MS/MS analysis to identify MHC II peptides derived from endogenous proteins expressed in freshly isolated murine splenic DCs. The cell number was enriched in vivo upon treatment with Flt3L-B16 melanoma cells. In a typical experiment, starting with about 5× 108 splenic DCs, we were able to reliably identify a repertoire of over 100 MHC II peptides originating from about 55 proteins localized in membrane (23%), intracellular (26%), endo-lysosomal (12%), nuclear (14%) and extracellular (25%) compartments. Using synthetic isotopically labeled peptides corresponding to the sequences of representative bound MHC II peptides, we quantified by LC-MS relative peptide abundance. In a single experiment, peptides were detected in a wide concentration range spanning from 2.5 fmol/μL to 12 pmol/μL or from approximately 13 copies to 2×105 copies per DC. These peptides were found in similar amounts on B cells where we detected about 80 peptides originating from 55 proteins distributed homogenously within the same cellular compartments as in DCs. About 90 different binding motifs predicted by the epitope prediction algorithm were found within the sequences of the identified MHC II peptides. These results set a foundation for future studies to quantitatively investigate the MHC II repertoire on DCs generated under different immunization conditions. PMID:21913724

  18. 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.

  19. Lung dendritic cells and the inflammatory response.

    PubMed

    Grayson, Mitchell H

    2006-05-01

    To discuss the role of conventional and plasmacytoid dendritic cells in inducing and modulating immune responses in the lung. The primary literature and selected review articles studying the role of dendritic cells in both rodent and human lungs as identified via a PubMed/MEDLINE search using the keywords dendritic cell, antigen-presenting cell, viral airway disease, asthma, allergy, and atopy. The author's knowledge of the field was used to identify studies that were relevant to the stated objective. Dendritic cells are well positioned in the respiratory tract and other mucosal surfaces to respond to any foreign protein. These cells are crucial to the initiation of the adaptive immune response through induction of antigen specific T-cell responses. These cells also play an important role in the regulation of developing and ongoing immune responses, an area that is currently under intense investigation. This review discusses the various subsets of human and rodent dendritic cells and the pathways involved in antigen processing and subsequent immune regulation by dendritic cells in the lung using both viral and nonviral allergenic protein exposure as examples. Conventional and plasmacytoid dendritic cells are uniquely situated in the immune cascade to not only initiate but also modulate immune responses. Therapeutic interventions in allergic and asthmatic diseases will likely be developed to take advantage of this exclusive position of the dendritic cell.

  20. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro

    PubMed Central

    Carlsson, Johan A.; Wold, Agnes E.; Sandberg, Ann-Sofie; Östman, Sofia M.

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violetlow) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells. PMID:26619195

  1. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro.

    PubMed

    Carlsson, Johan A; Wold, Agnes E; Sandberg, Ann-Sofie; Östman, Sofia M

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violet low) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells.

  2. [Disseminated interdigitating dendritic cell sarcoma].

    PubMed

    Santarelli, Ignacio M; Veltri, Mariano; Manzella, Diego J; Avagnina, María Alejandra; Pereyra, Pablo M; Chavín, Hernán C

    2017-01-01

    A 70 year-old woman was admitted to our hospital with a 3-month history of abdominal pain, weight loss and night sweats. On physical examination, she presented with a 5 cm diameter abdominal mass extended from epigastrium to the left flank, and at least three bilateral supraclavicular adenopathies. A disseminated interdigitating dendritic cell sarcoma was diagnosed through a biopsy of the abdominal mass. After that, a CHOP regime (cyclophosphamide, doxorubicin, vincristine and prednisone) was iniciated. She died after completion of the first cycle of treatment, six months after diagnosis.

  3. 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

  4. VEGF-A promotes IL-17A-producing γδ T cell accumulation in mouse skin and serves as a chemotactic factor for plasmacytoid dendritic cells.

    PubMed

    Suzuki, Takahiro; Hirakawa, Satoshi; Shimauchi, Takatoshi; Ito, Taisuke; Sakabe, Jun-ichi; Detmar, Michael; Tokura, Yoshiki

    2014-05-01

    IL-17-producing CD4(+) T (Th17) cells and their cytokines, IL-17A and IL-22, are deeply involved in the pathogenesis of psoriasis by stimulating epidermal keratinocytes to proliferate and to produce cytokines/chemokines and vascular endothelial growth factor (VEGF)-A. Plasmacytoid dendritic cells (pDCs), infiltrating in psoriatic lesions, are known to exacerbate the Th17-mediated pathogenesis of psoriasis. To address the initiative role of VEGF-A in the development of psoriasis and the pDC accumulation. Numerical changes and VEGF receptor 1 (VEGFR1) and VEGFR2 expressions were investigated in skin-infiltrating T cells and pDCs of K14-VEGF-A transgenic (Tg) and wild type (WT) mice. The chemotactic properties of VEGF-A for purified splenic pDCs were also evaluated by real-time chemotaxis assay. By flow cytometry and immunohistochemistry, we observed that the number of dermal IL-17A(+) γδ T cells, but not CD4(+) T cells, was increased in VEGF-A Tg mice, suggesting that the main source of IL-17A was γδ T cells. Moreover, we identified pDCs as 440c(+) cells by immunohistochemistry and as PDCA-1(+)B220(+) cells by flow cytometry, and found that pDCs infiltrated at a higher frequency in VEGF-A Tg than WT mice. pDCs, but not γδ T cells, isolated from the skin expressed VEGFR1 and VEGFR2. Freshly isolated splenic pDCs expressed both receptors after 48-h cultivation. pDCs did not produce cytokines in response to VEGF-A, however, they had a strong velocity of chemotaxis toward VEGF-A at a comparable level to chemerin. These findings suggest that VEGF-A functions as not only a downstream enhancer but also an upstream initiator by chemoattracting pDCs in psoriatic lesions. Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Human macrophage and dendritic cell-specific silencing of high-mobility group protein B1 ameliorates sepsis in a humanized mouse model.

    PubMed

    Ye, Chunting; Choi, Jang-Gi; Abraham, Sojan; Wu, Haoquan; Diaz, Dolores; Terreros, Daniel; Shankar, Premlata; Manjunath, N

    2012-12-18

    Hypersecretion of cytokines by innate immune cells is thought to initiate multiple organ failure in murine models of sepsis. Whether human cytokine storm also plays a similar role is not clear. Here, we show that human hematopoietic cells are required to induce sepsis-induced mortality following cecal ligation and puncture (CLP) in the severely immunodeficient nonobese diabetic (NOD)/SCID/IL2Rγ(-/-) mice, and siRNA treatment to inhibit HMGB1 release by human macrophages and dendritic cells dramatically reduces sepsis-induced mortality. Following CLP, compared with immunocompetent WT mice, NOD/SCID/IL2Rγ(-/-) mice did not show high levels of serum HMGB1 or murine proinflammatory cytokines and were relatively resistant to sepsis-induced mortality. In contrast, NOD/SCID/IL2Rγ(-/-) mice transplanted with human hematopoietic stem cells [humanized bone marrow liver thymic mice (BLT) mice] showed high serum levels of HMGB1, as well as multiple human but not murine proinflammatory cytokines, and died uniformly, suggesting human cytokines are sufficient to induce organ failure in this model. Moreover, targeted delivery of HMGB1 siRNA to human macrophages and dendritic cells using a short acetylcholine receptor (AchR)-binding peptide [rabies virus glycoprotein (RVG)-9R] effectively suppressed secretion of HMGB1, reduced the human cytokine storm, human lymphocyte apoptosis, and rescued humanized mice from CLP-induced mortality. siRNA treatment was also effective when started after the appearance of sepsis symptoms. These results show that CLP in humanized mice provides a model to study human sepsis, HMGB1 siRNA might provide a treatment strategy for human sepsis, and RVG-9R provides a tool to deliver siRNA to human macrophages and dendritic cells that could potentially be used to suppress a variety of human inflammatory diseases.

  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. 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.

  8. Migration patterns of dendritic cells in the mouse. Traffic from the blood, and T cell-dependent and -independent entry to lymphoid tissues

    PubMed Central

    1988-01-01

    Dendritic cells (DC) are critical accessory cells for primary immune responses and they may be important stimulators of transplantation reactions, but little is known of their traffic into the tissues. We have studied the migration of purified splenic DC and T lymphocytes, labeled with 111Indium-tropolone, in syngeneic and allogeneic mice. First we demonstrate that DC can migrate from the blood into some lymphoid and nonlymphoid tissues. Immediately after intravenous administration, radio-labeled DC were sequestered in the lungs, but they actively migrated into the liver and spleen and reached equilibrium levels between 3 and 24 h after transfer. At least half of the radiolabel accumulated in the liver, but the spleen was the principal site of DC localization in terms of specific activity (radiolabel per weight of tissue). DC were unable to enter Peyer's patches, or mesenteric and other peripheral lymph nodes from the bloodstream. This was also true in splenectomized recipients, where the otherwise spleen-seeking DC were quantitatively diverted to the liver. In contrast, T cells homed readily to the spleen and lymph nodes of normal mice and increased numbers were present in these tissues in splenectomized mice. Thus, unlike T cells, DC cannot recirculate from blood to lymph via the nodes. We then show that migration of DC from the blood into the spleen is dependent on the presence of T cells: DC did not enter the spleens of nude mice, but when they were reconstituted with T cells the numbers entering the spleen resembled those in euthymic mice. In nude mice, as in splenectomized recipients, the DC that would normally enter the spleen were quantitatively diverted to the liver. These findings suggest that there is a spleen- liver equilibrium for DC, that may be akin to that existing between spleen and lymph node for T cells. Finally, we followed the traffic of radiolabeled DC via the afferent lymphatics after subcutaneous footpad inoculation. DC accumulated in the

  9. Blockade of excitatory synaptogenesis with proximal dendrites of dentate granule cells following rapamycin treatment in a mouse model of temporal lobe epilepsy

    PubMed Central

    Yamawaki, Ruth; Thind, Khushdev; Buckmaster, Paul S.

    2014-01-01

    Inhibiting the mTOR signaling pathway with rapamycin blocks granule cell axon (mossy fiber) sprouting after epileptogenic injuries, including pilocarpine-induced status epilepticus. However, it remains unclear whether axons from other types of neurons sprout into the inner molecular layer and synapse with granule cell dendrites despite rapamycin treatment. If so, other aberrant positive-feedback networks might develop. To test this possibility stereological electron microscopy was used to estimate numbers of excitatory synapses in the inner molecular layer per hippocampus in pilocarpine-treated control mice, in mice 5 d after pilocarpine-induced status epilepticus, and after status epilepticus and daily treatment beginning 24 h later with rapamycin or vehicle for 2 months. The optical fractionator method was used to estimate numbers of granule cells in Nissl-stained sections so that numbers of excitatory synapses in the inner molecular layer per granule cell could be calculated. Control mice had an average of 2280 asymmetric synapses in the inner molecular layer per granule cell, which was reduced to 63% of controls 5 d after status epilepticus, recovered to 93% of controls in vehicle-treated mice 2 months after status epilepticus, but remained at only 63% of controls in rapamycin-treated mice. These findings reveal that rapamycin prevented excitatory axons from synapsing with proximal dendrites of granule cells and raise questions about the recurrent excitation hypothesis of temporal lobe epilepsy. PMID:25234294

  10. Production of interferons by dendritic cells, plasmacytoid cells, natural killer cells, and interferon-producing killer dendritic cells.

    PubMed

    Vremec, David; O'Keeffe, Meredith; Hochrein, Hubertus; Fuchsberger, Martina; Caminschi, Irina; Lahoud, Mireille; Shortman, Ken

    2007-02-01

    The capacity of mouse spleen conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) to produce interferon-gamma (IFN-gamma) or IFN-alpha was assessed, and compared with that of natural killer (NK) cells and the recently identified interferon-producing killer dendritic cells (IKDCs), both of which are frequent contaminants in DC preparations. Fully developed cDCs or pDCs, if free of NK cells or IKDCs, showed little capacity for IFN-gamma production. However, an early developmental form of the CD4-8+ cDC subtype, and the Ly6C- Ly49Q- pDC subtype, both were able to produce moderate amounts of IFN-gamma, although less than IKDCs. In response to toll-like receptor 9 stimuli, both the Ly6C+ Ly49Q+ and the Ly6C- Ly49Q- pDC subtypes were effective producers of IFN-alpha. However, IKDCs, which efficiently produced IFN-gamma and showed immediate cytotoxicity on NK target cells, did not produce IFN-alpha under these conditions.

  11. Dendritic cells in hematological malignancies.

    PubMed

    Galati, Domenico; Corazzelli, Gaetano; De Filippi, Rosaria; Pinto, Antonio

    2016-12-01

    Dendritic cells (DCs) are bone-marrow-derived immune cells accounted for a crucial role in initiating and modulating the adaptive immune response and supporting the innate immune response independently from T cells. While functioning as the most effective antigen-presenting cells within the immune system, DCs can otherwise induce tolerance in central and peripheral lymphoid organs acting therefore as suppressors rather than stimulators of the immune response. Within mechanisms regulating antitumor immunity, DCs can capture antigens from viable or damaged tumor cells and present the processed peptides to T-cells to prompt the generation and maintenance of an effective tumor-specific T-cell response. Upon a complex cross-talk with other cellular components of the tumor microenvironment, DCs can, on the other hand, exert a potent antigen-dependent and -independent tolerogenic function by favoring the process of tumor immune evasion. Due to this dual-role in balancing antitumor immunity and tolerance, possibly linked to distinct developmental stages and functional subsets, several studies have addressed the regulatory significance of DCs in different types of malignancies. This review summarizes the most significant pieces of evidence highlighting the critical relevance of bone marrow-derived DCs within the immune pathways regulating pathogenesis and progression of hemopoietic tumors. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Triggering of dendritic cell apoptosis by xanthohumol.

    PubMed

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

    2010-07-01

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

  13. 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

  14. 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.

  15. [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.

  16. The impact of development and sensory deprivation on dendritic protrusions in the mouse barrel cortex.

    PubMed

    Chen, Chia-Chien; Bajnath, Adesh; Brumberg, Joshua C

    2015-06-01

    Dendritic protrusions (spines and filopodia) are structural indicators of synapses that have been linked to neuronal learning and memory through their morphological alterations induced by development and experienced-dependent activities. Although previous studies have demonstrated that depriving sensory experience leads to structural changes in neocortical organization, the more subtle effects on dendritic protrusions remain unclear, mostly due to focus on only one specific cell type and/or age of manipulation. Here, we show that sensory deprivation induced by whisker trimming influences the dendritic protrusions of basilar dendrites located in thalamocortical recipient lamina (IV and VI) of the mouse barrel cortex in a layer-specific manner. Following 1 month of whisker trimming after birth, the density of dendritic protrusions increased in layer IV, but decreased in layer VI. Whisker regrowth for 1 month returned protrusion densities to comparable level of age-matched controls in layer VI, but not in layer IV. In adults, chronic sensory deprivation led to an increase in protrusion densities in layer IV, but not in layer VI. In addition, chronic pharmacological blockade of N-methyl-d-aspartate receptors (NMDARs) increased protrusion density in both layers IV and VI, which returned to the control level after 1 month of drug withdrawal. Our data reveal that different cortical layers respond to chronic sensory deprivation in different ways, with more pronounced effects during developmental critical periods than adulthood. We also show that chronically blocking NMDARs activity during developmental critical period also influences the protrusion density and morphology in the cerebral cortex.

  17. 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

  18. Morphological properties of mouse retinal ganglion cells.

    PubMed

    Coombs, J; van der List, D; Wang, G-Y; Chalupa, L M

    2006-06-19

    The mouse retina offers an increasingly valuable model for vision research given the possibilities for genetic manipulation. Here we assess how the structural properties of mouse retinal ganglion cells relate to the stratification pattern of the dendrites of these neurons within the inner plexiform layer. For this purpose, we used 14 morphological measures to classify mouse retinal ganglion cells parametrically into different clusters. Retinal ganglion cells were labeled in one of three ways: Lucifer Yellow injection, 'DiOlistics' or transgenic expression of yellow fluorescent protein. The resulting analysis of 182 cells revealed 10 clusters of monostratified cells, with dendrites confined to either On or Off sublaminae of the inner plexiform layer, and four clusters of bistratified cells, dendrites spanning the On and Off sublaminae. We also sought to establish how these parametrically identified retinal ganglion cell clusters relate to cell types identified previously on the basis of immunocytochemical staining and the expression of yellow fluorescent protein. Cells labeled with an antibody against melanopsin were found to be located within a single cluster, while those labeled with the SMI-32 antibody were in four different clusters. Yellow fluorescent protein expressing cells were distributed within 13 of the 14 clusters identified here, which demonstrates that yellow fluorescent protein expression is a useful method for labeling virtually the entire population of mouse retinal ganglion cells. Collectively, these findings provide a valuable baseline for future studies dealing with the effects of genetic mutations on the morphological development of these neurons.

  19. 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.

  20. GM-CSF Mouse Bone Marrow Cultures Comprise a Heterogeneous Population of CD11c(+)MHCII(+) Macrophages and Dendritic Cells.

    PubMed

    Helft, Julie; Böttcher, Jan; Chakravarty, Probir; Zelenay, Santiago; Huotari, Jatta; Schraml, Barbara U; Goubau, Delphine; Reis e Sousa, Caetano

    2015-06-16

    Dendritic cells (DCs) are key players in the immune system. Much of their biology has been elucidated via culture systems in which hematopoietic precursors differentiate into DCs under the aegis of cytokines. A widely used protocol involves the culture of murine bone marrow (BM) cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) to generate BM-derived DCs (BMDCs). BMDCs express CD11c and MHC class II (MHCII) molecules and share with DCs isolated from tissues the ability to present exogenous antigens to T cells and to respond to microbial stimuli by undergoing maturation. We demonstrate that CD11c(+)MHCII(+) BMDCs are in fact a heterogeneous group of cells that comprises conventional DCs and monocyte-derived macrophages. DCs and macrophages in GM-CSF cultures both undergo maturation upon stimulation with lipopolysaccharide but respond differentially to the stimulus and remain separable entities. These results have important implications for the interpretation of a vast array of data obtained with DC culture systems. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Interstitial dendritic cell guidance by haptotactic chemokine gradients.

    PubMed

    Weber, Michele; Hauschild, Robert; Schwarz, Jan; Moussion, Christine; de Vries, Ingrid; Legler, Daniel F; Luther, Sanjiv A; Bollenbach, Tobias; Sixt, Michael

    2013-01-18

    Directional guidance of cells via gradients of chemokines is considered crucial for embryonic development, cancer dissemination, and immune responses. Nevertheless, the concept still lacks direct experimental confirmation in vivo. Here, we identify endogenous gradients of the chemokine CCL21 within mouse skin and show that they guide dendritic cells toward lymphatic vessels. Quantitative imaging reveals depots of CCL21 within lymphatic endothelial cells and steeply decaying gradients within the perilymphatic interstitium. These gradients match the migratory patterns of the dendritic cells, which directionally approach vessels from a distance of up to 90-micrometers. Interstitial CCL21 is immobilized to heparan sulfates, and its experimental delocalization or swamping the endogenous gradients abolishes directed migration. These findings functionally establish the concept of haptotaxis, directed migration along immobilized gradients, in tissues.

  2. Identification and isolation of synovial dendritic cells.

    PubMed

    Pettit, Allison R; Cavanagh, Lois; Boyce, Amanda; Padmanabha, Jagadish; Peng, Judy; Thomas, Ranjeny

    2007-01-01

    In rheumatoid arthritis patients, three compartments need to be considered: peripheral blood, synovial fluid, and synovial tissue. Dendritic cells characterized from each compartment have different properties. The methods given are based on cell sorting for isolation of cells, and flow cytometry and immunohistochemical staining for analysis of cells in these compartments.

  3. Somatic translocation: a novel mechanism of granule cell dendritic dysmorphogenesis and dispersion

    PubMed Central

    Murphy, Brian L.; Danzer, Steve C.

    2011-01-01

    Pronounced neuronal remodeling is a hallmark of temporal lobe epilepsy. Here, we use real-time confocal imaging of tissue from mouse brain to demonstrate that remodeling can involve fully-differentiated granule cells following translocation of the soma into an existing apical dendrite. Somatic translocation converts dendritic branches into primary dendrites and shifts adjacent apical dendrites to the basal pole of the cell. Moreover, somatic translocation contributes to the dispersion of the granule cell body layer in vitro, and when granule cell dispersion is induced in vivo, the dispersed cells exhibit virtually identical derangements of their dendritic structures. Together, these findings identify novel forms of neuronal plasticity which contribute to granule cell dysmorphogenesis in the epileptic brain. PMID:21414917

  4. Administration of polysaccharides from Antrodia camphorata modulates dendritic cell function and alleviates allergen-induced T helper type 2 responses in a mouse model of asthma.

    PubMed

    Liu, Ko-Jiunn; Leu, Sy-Jye; Su, Ching-Hua; Chiang, Bor-Luen; Chen, Yi-Lien; Lee, Yueh-Lun

    2010-03-01

    Asthma is a chronic disease characterized by airway inflammation caused by the dysregulated production of cytokines secreted by allergen-specific type 2 T helper (Th2) cells. Antrodia camphorata is a commonly used fungus in Asian folk medicine, and A. camphorata polysaccharides are reported to possess anti-cancer activities. In this study, the immunomodulatory effects of purified fractionated polysaccharides (GF2) from A. camphorata on dendritic cells (DCs) and their potential preventive effects against ovalbumin (OVA) -induced asthma were investigated. In the presence of GF2, lipopolysaccharide (LPS) -activated DCs exhibited up-regulated expression of major histocompatibility complex (MHC) class II and co-stimulatory molecules, as well as enhanced interleukin-10 (IL-10) and IL-12 production. GF2 treatment on LPS-activated DCs suppressed naïve CD4(+) T-cell proliferation and Th2 cell polarization with IL-10 production in an allogeneic mixed lymphocyte reaction. In animal experiments, a high dose of GF2 efficiently reduced expression levels of OVA-specific immunoglobulin G1 (IgG1) and IgE. However, lower doses of GF2 significantly enhanced OVA-specific IgG2a production. Our data also showed that administration of GF2 dose-dependently inhibited the development of airway hyperresponsiveness, airway eosinophilia and Th2 responses. OVA-specific CD4(+) T cells from higher doses of GF2-treated mice had significantly lower proliferative capacities compared with control mice. Moreover, treatment with GF2 significantly increased the high levels of IL-10 and low levels of interferon-gamma produced by T cells. Taken together, these data indicate that administration of A. camphorata polysaccharides (GF2) may have therapeutic potential when used as an adjuvant for the immunomodulatory treatment of allergic asthma.

  5. The gene expression profile of CD11c+ CD8α- dendritic cells in the pre-diabetic pancreas of the NOD mouse.

    PubMed

    Beumer, Wouter; Welzen-Coppens, Jojanneke M C; van Helden-Meeuwsen, Cornelia G; Gibney, Sinead M; Drexhage, Hemmo A; Versnel, Marjan A

    2014-01-01

    Two major dendritic cell (DC) subsets have been described in the pancreas of mice: The CD11c+ CD8α- DCs (strong CD4+ T cell proliferation inducers) and the CD8α+ CD103+ DCs (T cell apoptosis inducers). Here we analyzed the larger subset of CD11c+ CD8α- DCs isolated from the pancreas of pre-diabetic NOD mice for genome-wide gene expression (validated by Q-PCR) to elucidate abnormalities in underlying gene expression networks. CD11c+ CD8α- DCs were isolated from 5 week old NOD and control C57BL/6 pancreas. The steady state pancreatic NOD CD11c+ CD8α- DCs showed a reduced expression of several gene networks important for the prime functions of these cells, i.e. for cell renewal, immune tolerance induction, migration and for the provision of growth factors including those for beta cell regeneration. A functional in vivo BrdU incorporation test showed the reduced proliferation of steady state pancreatic DC. The reduced expression of tolerance induction genes (CD200R, CCR5 and CD24) was supported on the protein level by flow cytometry. Also previously published functional tests on maturation, immune stimulation and migration confirm the molecular deficits of NOD steady state DC. Despite these deficiencies NOD pancreas CD11c+ CD8α- DCs showed a hyperreactivity to LPS, which resulted in an enhanced pro-inflammatory state characterized by a gene profile of an enhanced expression of a number of classical inflammatory cytokines. The enhanced up-regulation of inflammatory genes was supported by the in vitro cytokine production profile of the DCs. In conclusion, our data show that NOD pancreatic CD11c+ CD8α- DCs show various deficiencies in steady state, while hyperreactive when encountering a danger signal such as LPS.

  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. Time-Lapse Retinal Ganglion Cell Dendritic Field Degeneration Imaged in Organotypic Retinal Explant Culture

    PubMed Central

    Johnson, Thomas V.; Oglesby, Ericka N.; Steinhart, Matthew R.; Cone-Kimball, Elizabeth; Jefferys, Joan; Quigley, Harry A.

    2016-01-01

    Purpose To develop an ex vivo organotypic retinal explant culture system suitable for multiple time-point imaging of retinal ganglion cell (RGC) dendritic arbors over a period of 1 week, and capable of detecting dendrite neuroprotection conferred by experimental treatments. Methods Thy1-YFP mouse retinas were explanted and maintained in organotypic culture. Retinal ganglion cell dendritic arbors were imaged repeatedly using confocal laser scanning microscopy. Maximal projection z-stacks were traced by two masked investigators and dendritic fields were analyzed for characteristics including branch number, size, and complexity. One group of explants was treated with brain derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) added to the culture media. Changes in individual dendritic fields over time were detected using pair-wise comparison testing. Results Retinal ganglion cells in mouse retinal explant culture began to degenerate after 3 days with 52.4% surviving at 7 days. Dendritic field parameters showed minimal change over 8 hours in culture. Intra- and interobserver measurements of dendrite characteristics were strongly correlated (Spearman rank correlations consistently > 0.80). Statistically significant (P < 0.001) dendritic tree degeneration was detected following 7 days in culture including: 40% to 50% decreases in number of branch segments, number of junctions, number of terminal branches, and total branch length. Scholl analyses similarly demonstrated a significant decrease in dendritic field complexity. Treatment of explants with BDNF+CNTF significantly attenuated dendritic field degeneration. Conclusions Retinal explant culture of Thy1-YFP tissue provides a useful model for time-lapse imaging of RGC dendritic field degeneration over a course of several days, and is capable of detecting neuroprotective amelioration of dendritic pruning within individual RGCs. PMID:26811145

  8. ISOLATION OF CHICKEN FOLLICULAR DENDRITIC CELLS

    USDA-ARS?s Scientific Manuscript database

    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...

  9. Cells with dendritic cell morphology and immunophenotype, binuclear morphology, and immunosuppressive function in dendritic cell cultures.

    PubMed

    Dong, Rong; Moulding, Dale; Himoudi, Nourredine; Adams, Stuart; Bouma, Gerben; Eddaoudi, Ayad; Basu, B Piku; Derniame, Sophie; Chana, Prabhjoat; Duncan, Andrew; Anderson, John

    2011-01-01

    Culturing of human peripheral blood CD14 positive monocytes is a method for generation of dendritic cells (DCs) for experimental purposes or for use in clinical grade vaccines. When culturing human DCs in this manner for clinical vaccine production, we noticed that 5-10% of cells within the bulk culture were binuclear or multiple nuclear, but had typical dendritic cell morphology and immunophenotype. We refer to the cells as binuclear cells in dendritic cell cultures (BNiDCs). By using single cell PCR analysis of mitochondrial DNA polymorphisms we demonstrated that approximately 20-25% of cells in DC culture undergo a fusion event. Flow sorted BNiDC express low HLA-DR and IL-12p70, but high levels of IL-10. In mixed lymphocyte reactions, purified BNiDC suppressed lymphocyte proliferation. Blockade of dendritic cell-specific transmembrane protein (DC-STAMP) decreased the number of binuclear cells in DC cultures. BNiDC represent a potentially tolerogenic population within DC preparations for clinical use.

  10. Dendritic stratification differs among retinal OFF bipolar cell types in the absence of rod photoreceptors

    PubMed Central

    Puller, Christian; Arbogast, Patrick; Keeley, Patrick W.; Reese, Benjamin E.; Haverkamp, Silke

    2017-01-01

    Retinal OFF bipolar cells show distinct connectivity patterns with photoreceptors in the wild-type mouse retina. Some types are cone-specific while others penetrate further through the outer plexiform layer (OPL) to contact rods in addition to cones. To explore dendritic stratification of OFF bipolar cells in the absence of rods, we made use of the ‘cone-full’ Nrl-/- mouse retina in which all photoreceptor precursor cells commit to a cone fate including those which would have become rods in wild-type retinas. The dendritic distribution of OFF bipolar cell types was investigated by confocal and electron microscopic imaging of immunolabeled tissue sections. The cells’ dendrites formed basal contacts with cone terminals and expressed the corresponding glutamate receptor subunits at those sites, indicating putative synapses. All of the four analyzed cell populations showed distinctive patterns of vertical dendritic invasion through the OPL. This disparate behavior of dendritic extension in an environment containing only cone terminals demonstrates type-dependent specificity for dendritic outgrowth in OFF bipolar cells: rod terminals are not required for inducing dendritic extension into distal areas of the OPL. PMID:28257490

  11. 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

  12. Pplase of Dermatophagoides farinae promotes ovalbumin-induced airway allergy by modulating the functions of dendritic cells in a mouse model

    PubMed Central

    Wang, Hui; Mo, Lihua; Xiao, Xiaojun; An, Shu; Liu, Xiaoyu; Ba, Jinge; Wu, Weifang; Ran, Pixin; Yang, Pingchang; Liu, Zhigang

    2017-01-01

    Our previous studies revealed that many proteins in addition to the known allergens of D. farinae have not been fully characterized. We observed that Pplase did not respond to serum collected from patients sensitized to D. farinae. In a mouse model, Pplase significantly enhanced airway hyperresponsiveness (AHR) and Th2 responses induced by ovalbumin (OVA) compared with mice treated with OVA alone. Moreover, exposure to Pplase significantly increased the expression of IRF4, CD80, CD83, MHCII and TNF-α in DC2.4 cells, which was abolished in the presence of a TLR4 inhibitor. In vitro T cell polarization experiments revealed that Pplase alone could not induce T cell polarization but enhanced T cell polarization together with OVA. In addition, transfer of Pplase-primed bone marrow-derived DCs (BMDCs) to naïve mice enhanced AHR and Th2 immune responses in mice sensitized to OVA. In conclusion, Pplase is not an allergen of D. farinae but can activate DC cells to facilitate OVA-induced allergic responses. PMID:28240301

  13. Suppression of zinc dendrites in zinc electrode power cells

    NASA Technical Reports Server (NTRS)

    Damjanovic, A.; Diggle, J. W.

    1970-01-01

    Addition of various tetraalkyl quarternary ammonium salts, to alkaline zincate electrolyte of cell, prevents formation of zinc dendrites during charging of zinc electrode. Electrode capacity is not impaired and elimination of dendrites prolongs cell life.

  14. Dendritic vulnerability in neurodegenerative disease: insights from analyses of cortical pyramidal neurons in transgenic mouse models

    PubMed Central

    Weaver, Christina M.; Rocher, Anne B.; Rodriguez, Alfredo; Crimins, Johanna L.; Dickstein, Dara L.; Wearne, Susan L.; Hof, Patrick R.

    2011-01-01

    In neurodegenerative disorders, such as Alzheimer’s disease, neuronal dendrites and dendritic spines undergo significant pathological changes. Because of the determinant role of these highly dynamic structures in signaling by individual neurons and ultimately in the functionality of neuronal networks that mediate cognitive functions, a detailed understanding of these changes is of paramount importance. Mutant murine models, such as the Tg2576 APP mutant mouse and the rTg4510 tau mutant mouse have been developed to provide insight into pathogenesis involving the abnormal production and aggregation of amyloid and tau proteins, because of the key role that these proteins play in neurodegenerative disease. This review showcases the multidimensional approach taken by our collaborative group to increase understanding of pathological mechanisms in neurodegenerative disease using these mouse models. This approach includes analyses of empirical 3D morphological and electrophysiological data acquired from frontal cortical pyramidal neurons using confocal laser scanning microscopy and whole-cell patch-clamp recording techniques, combined with computational modeling methodologies. These collaborative studies are designed to shed insight on the repercussions of dystrophic changes in neocortical neurons, define the cellular phenotype of differential neuronal vulnerability in relevant models of neurodegenerative disease, and provide a basis upon which to develop meaningful therapeutic strategies aimed at preventing, reversing, or compensating for neurodegenerative changes in dementia. PMID:20177698

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

    PubMed Central

    Ottobrini, Luisa; Biasin, Mara; Borelli, Manuela; Lucignani, Giovanni; Trabattoni, Daria; Clerici, Mario

    2016-01-01

    Introduction Dendritic cells play a key role as initiators of T-cell responses, and even if tumour antigen-loaded dendritic cells can induce anti-tumour responses, their efficacy has been questioned, suggesting a need to enhance immunization strategies. Matherials & Methods We focused on the characterization of bone marrow-derived dendritic cells pulsed with whole tumour lysate (TAA-DC), as a source of known and unknown antigens, in a mouse model of breast cancer (MMTV-Ras). Dendritic cells were evaluated for antigen uptake and for the expression of MHC class I/II and costimulatory molecules and markers associated with maturation. Results Results showed that antigen-loaded dendritic cells are characterized by a phenotypically semi-mature/mature profile and by the upregulation of genes involved in antigen presentation and T-cell priming. Activated dendritic cells stimulated T-cell proliferation and induced the production of high concentrations of IL-12p70 and IFN-γ but only low levels of IL-10, indicating their ability to elicit a TH1-immune response. Furthermore, administration of Antigen loaded-Dendritic Cells in MMTV-Ras mice evoked a strong anti-tumour response in vivo as demonstrated by a general activation of immunocompetent cells and the release of TH1 cytokines. Conclusion Data herein could be useful in the design of antitumoral DC-based therapies, showing a specific activation of immune system against breast cancer. PMID:26795765

  16. Dendritic cells and immunotherapy for cancer.

    PubMed

    Chang, David H; Dhodapkar, Madhav V

    2003-06-01

    Dendritic cells, nature's adjuvant, are antigen-presenting cells specialized to initiate and regulate immunity. Their potent antigen-presenting function has encouraged targeting of dendritic cells (DCs) for harnessing the immune system against cancer. DCs are efficient at activating not only CD4+ helper T-cells and CD8+ killer T-cells but also B-cells and innate effectors such as natural killer and natural killer T-cells. Early studies of adoptive transfer of tumor antigen-loaded DCs have shown promise. However, DC vaccination is at an early stage, and several parameters still need to be established. The complexity of the DC system brings about the necessity for its rational manipulation for achieving protective and therapeutic immunity in patients.

  17. Dendritic Cell Subsets in Type 1 Diabetes: Friend or Foe?

    PubMed Central

    Morel, Penelope A.

    2013-01-01

    Type 1 diabetes (T1D) is a T cell mediated autoimmune disease characterized by immune mediated destruction of the insulin-producing β cells in the islets of Langerhans. Dendritic cells (DC) have been implicated in the pathogenesis of T1D and are also used as immunotherapeutic agents. Plasmacytoid (p)DC have been shown to have both protective and pathogenic effects and a newly described merocytic DC population has been shown to break tolerance in the mouse model of T1D, the non-obese diabetic (NOD) mouse. We have used DC populations to prevent the onset of T1D in NOD mice and clinical trials of DC therapy in T1D diabetes have been initiated. In this review we will critically examine the recent published literature on the role of DC subsets in the induction and regulation of the autoimmune response in T1D. PMID:24367363

  18. Olfactory Sensory Neurons Control Dendritic Complexity of Mitral Cells via Notch Signaling

    PubMed Central

    Saito, Tetsuichiro

    2016-01-01

    Mitral cells (MCs) of the mammalian olfactory bulb have a single primary dendrite extending into a single glomerulus, where they receive odor information from olfactory sensory neurons (OSNs). Molecular mechanisms for controlling dendritic arbors of MCs, which dynamically change during development, are largely unknown. Here we found that MCs displayed more complex dendritic morphologies in mouse mutants of Maml1, a crucial gene in Notch signaling. Similar phenotypes were observed by conditionally misexpressing a dominant negative form of MAML1 (dnMAML1) in MCs after their migration. Conversely, conditional misexpression of a constitutively active form of Notch reduced their dendritic complexity. Furthermore, the intracellular domain of Notch1 (NICD1) was localized to nuclei of MCs. These findings suggest that Notch signaling at embryonic stages is involved in the dendritic complexity of MCs. After the embryonic misexpression of dnMAML1, many MCs aberrantly extended dendrites to more than one glomerulus at postnatal stages, suggesting that Notch signaling is essential for proper formation of olfactory circuits. Moreover, dendrites in cultured MCs were shortened by Jag1-expressing cells. Finally, blocking the activity of Notch ligands in OSNs led to an increase in dendritic complexity as well as a decrease in NICD1 signals in MCs. These results demonstrate that the dendritic complexity of MCs is controlled by their presynaptic partners, OSNs. PMID:28027303

  19. Bortezomib as a new therapeutic approach for blastic plasmacytoid dendritic cell neoplasm.

    PubMed

    Philippe, Laure; Ceroi, Adam; Bôle-Richard, Elodie; Jenvrin, Alizée; Biichle, Sabeha; Perrin, Sophie; Limat, Samuel; Bonnefoy, Francis; Deconinck, Eric; Saas, Philippe; Garnache-Ottou, Francine; Angelot-Delettre, Fanny

    2017-08-10

    Blastic plasmacytoid dendritic cell neoplasm is an aggressive hematological malignancy with a poor prognosis. No consensus for optimal treatment modalities is available today. Targeting the NF-κB pathway is considered as a promising approach since blastic plasmacytoid dendritic cell neoplasm have been reported to exhibit a constitutive activation of the NF-κB pathway. Moreover, NF-κB inhibition in blastic plasmacytoid dendritic cell neoplasm cell lines using either an experimental specific inhibitor JSH23 or the clinical drug bortezomib interferes in vitro with leukemic cell proliferation and survival. We extended here these data by showing that primary blastic plasmacytoid dendritic cell neoplasm cells from 7 patients were sensitive to bortezomib-induced cell death. We confirmed that bortezomib inhibits efficiently the phosphorylation of the RelA NF-κB subunit in blastic plasmacytoid dendritic cell neoplasm cell lines and primary cells from patients in vitro and in vivo in a mouse model. Then, we demonstrated that bortezomib can be associated with other drugs used in different chemotherapy regimens to improve its impact on leukemic cell death. Indeed, when primary blastic plasmacytoid dendritic cell neoplasm cells from a patient were grafted, bortezomib treatment significantly increased mouse survival, and was associated with a significant decrease of circulating leukemic cells and RelA NF-κB subunit expression. Overall, our results provide a rationale for the use of bortezomib in combination with other chemotherapy for the treatment of blastic plasmacytoid dendritic cell neoplasm patients. Based on our data, a prospective clinical trial combining proteasome inhibitor with classical drugs could be envisaged. Copyright © 2017, Ferrata Storti Foundation.

  20. Dendritic Arborization Patterns of Small Juxtaglomerular Cell Subtypes within the Rodent Olfactory Bulb

    PubMed Central

    Bywalez, Wolfgang G.; Ona-Jodar, Tiffany; Lukas, Michael; Ninkovic, Jovica; Egger, Veronica

    2017-01-01

    Within the glomerular layer of the rodent olfactory bulb, numerous subtypes of local interneurons contribute to early processing of incoming sensory information. Here we have investigated dopaminergic and other small local juxtaglomerular cells in rats and mice and characterized their dendritic arborization pattern with respect to individual glomeruli by fluorescent labeling via patching and reconstruction of dendrites and glomerular contours from two-photon imaging data. Dopaminergic neurons were identified in a transgenic mouse line where the expression of dopamine transporter (DAT) was labeled with GFP. Among the DAT+ cells we found a small short-axon cell (SAC) subtype featuring hitherto undescribed dendritic specializations. These densely ramifying structures clasped mostly around somata of other juxtaglomerular neurons, which were also small, non-dopaminergic and to a large extent non-GABAergic. Clasping SACs were observed also in wild-type mice and juvenile rats. In DAT+ SAC dendrites, single backpropagating action potentials evoked robust calcium entry throughout both clasping and non-clasping compartments. Besides clasping SACs, most other small neurons either corresponded to the classical periglomerular cell type (PGCs), which was never DAT+, or were undersized cells with a small dendritic tree and low excitability. Aside from the presence of clasps in SAC dendrites, many descriptors of dendritic morphology such as the number of dendrites and the extent of branching were not significantly different between clasping SACs and PGCs. However, a detailed morphometric analysis in relation to glomerular contours revealed that the dendrites of clasping SACs arborized mostly in the juxtaglomerular space and never entered more than one glomerulus (if at all), whereas most PGC dendrites were restricted to their parent glomerulus, similar to the apical tufts of mitral cells. These complementary arborization patterns might underlie a highly complementary functional

  1. Dendritic cells in systemic lupus erythematosus.

    PubMed

    Seitz, Heather M; Matsushima, Glenn K

    2010-04-01

    Systemic lupus erythematosus (SLE) persists as a chronic inflammatory autoimmune disease and is characterized by the production of autoantibodies and immune complexes that affect multiple organs. The underlying mechanism that triggers and sustains disease are complex and involve certain susceptibility genes and environmental factors. There have been several immune mediators linked to SLE including cytokines and chemokines that have been reviewed elsewhere [ 1-3 ]. A number of articles have reviewed the role of B cells and T cells in SLE [ 4-10 ]. Here, we focus on the role of dendritic cells (DC) and innate immune factors that may regulate autoreactive B cells.

  2. Role of Dendritic Cells in Immune Dysfunction

    NASA Technical Reports Server (NTRS)

    Savary, Cherylyn A.

    1997-01-01

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

  3. Human dendritic cells - stars in the skin.

    PubMed

    Klechevsky, Eynav

    2013-12-01

    "A properly functioning adaptive immune system signifies the best features of life. It is diverse beyond compare, tolerant without fail, and capable of behaving appropriately with a myriad of infections and other challenges. Dendritic cells (DCs) are required to explain how this remarkable system is energized and directed." This is a quote by one of the greatest immunologists our community has ever known, and the father of dendritic cells, Ralph Steinman. Steinman's discovery of DCs in 1973 and his subsequent research opened a new field of study within immunology: DC biology and in particular the role of DCs in immune regulation in health and disease. Here, I review themes from our work and others on the complex network of dendritic cells in the skin and discuss the significance of skin DCs in understanding aspects of host defense against infections, the pathology of inflammatory skin diseases, and speculate on the future effective immune-based therapies. © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Dendritic cell therapy for oncology roundtable conference

    PubMed Central

    2011-01-01

    2-3 September 2010, Brussels, Belgium The Dendritic Cell Therapy for Oncology Roundtable Conference was organized by Reliable Cancer Therapies and moderated by Prof. Dr. Steven De Vleeschouwer. The organizer, Reliable Cancer Therapies, is a Swiss non-profit organization that provides information on evidence-based cancer treatments and funding for the development of a selection of promising cancer therapies. In order to be able to give valuable information about dendritic cell (DC) therapy to patients and physicians, the organizing committee felt it necessary to organize this conference to get an up-to-date status of the academic DC therapy field, collect ideas to guide patients towards clinical trials and to induce cross-fertilization for protocol optimization. In total, 31 experts participated to an in-depth discussion about the status and the future development path for dendritic cell vaccines. The conference started with general presentations about cancer immunotherapy, followed by comprehensive overview presentations about the progress in DC vaccine development achieved by each speaker. At the end of the meeting, a thorough general discussion focused on key questions about what is needed to improve DC vaccines. This report does not cover all presentations, but aims to highlight selected points of interest, particularly relating to possible limitations and potential approaches to improvement of DC therapies specifically, and also immunotherapeutic interventions in general terms. PMID:21226916

  5. Apa2H1, the first head domain of Apa2 trimeric autotransporter adhesin, activates mouse bone marrow-derived dendritic cells and immunization with Apa2H1 protects against Actinobacillus pleuropneumoniae infection.

    PubMed

    Qin, Wanhai; Wang, Lei; Zhai, Ruidong; Ma, Qiuyue; Liu, Jianfang; Bao, Chuntong; Sun, Diangang; Zhang, Hu; Sun, Changjiang; Feng, Xin; Gu, Jingmin; Du, Chongtao; Han, Wenyu; Langford, P R; Lei, Liancheng

    2017-01-01

    Actinobacillus pleuropneumoniae is the causative pathogen of porcine pleuropneumonia, which results in large economic losses in the pig industry worldwide. There are, however, no effective subunit vaccines are available in the market owing to the various serotypes and the absence of cross-protection against this pathogen. Therefore, the selection of protective components is of great significance for vaccine development. We previously showed that trimeric autotransporter adhesins are important virulence factors of A. pleuropneumoniae. To determine the potential role in vaccine development of the functional head domain (Apa2H1) of Apa2, a trimeric autotransporter adhesin found in A. pleuropneumoniae, we obtained nature-like trimeric Apa2H1 using a prokaryotic expression system and co-culture of Apa2H1 with bone marrow derived dendritic cells (BMDCs) in vitro resulted in maturation of BMDCs, characterised by the up-regulation of CD83, MHC-II, CCR7, ICAM-I and the increased expression of factors related to B lymphoid cells stimulation, such as proliferation-inducing ligand (APRIL), B lymphocyte stimulator (BLyS) and B cell activating factor (BAFF). The in vivo results showed that vaccination with Apa2H1 resulted in the robust production of antigen-specific antibodies, modestly induced mixed Th1 and Th2 immunity, impaired bacterial colonization and dissemination, and improved mouse survival rates. This study is the first to show that Apa2H1 is antigenic and can be used as a component of a subunit vaccine against A. pleuropneumoniae infection, providing valuable reference material for the development of an effective vaccine against A. pleuropneumoniae. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Adherent cells in granulocyte-macrophage colony-stimulating factor-induced bone marrow-derived dendritic cell culture system are qualified dendritic cells.

    PubMed

    Li, Gong-Bo; Lu, Guang-Xiu

    2010-01-01

    A widely-used method for generating dendritic cell (DC) is to culture bone marrow cells in granulocyte-macrophage colony-stimulating factor (GM-CSF)-containing medium for 6-10 days. Usually, non-adherent cells are used as qualified dendritic cells while the adherent ones are discarded as "non-dendritic cells" or macrophages. In this study, we show that the adherent cells are nearly identical to the non-adherent cells in both dendritic cell surface markers expression and main dendritic cell-related functions, hence to prove that these "junk cells" are actually qualified dendritic cells.

  7. Inducible expression of endomorphins in murine dendritic cells.

    PubMed

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

    2012-12-15

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

  8. Generation of regulatory dendritic cells after treatment with paeoniflorin.

    PubMed

    Chen, Dan; Li, Yingxi; Wang, Xiaodong; Li, Keqiu; Jing, Yaqing; He, Jinghua; Qiang, Zhaoyan; Tong, Jingzhi; Sun, Ke; Ding, Wen; Kang, Yi; Li, Guang

    2016-08-01

    Regulatory dendritic cells are a potential therapeutic tool for assessing a variety of immune overreaction diseases. Paeoniflorin, a bioactive glucoside extracted from the Chinese herb white paeony root, has been shown to be effective at inhibiting the maturation and immunostimulatory function of murine bone marrow-derived dendritic cells. However, whether paeoniflorin can program conventional dendritic cells toward regulatory dendritic cells and the underlying mechanism remain unknown. Here, our study demonstrates that paeoniflorin can induce the production of regulatory dendritic cells from human peripheral blood monocyte-derived immature dendritic cells in the absence or presence of lipopolysaccharide (LPS) but not from mature dendritic cells, thereby demonstrating the potential of paeoniflorin as a specific immunosuppressive drug with fewer complications and side effects. These regulatory dendritic cells treated with paeoniflorin exhibited high CD11b/c and low CD80, CD86 and CD40 expression levels as well as enhanced abilities to capture antigen and promote the proliferation of CD4(+)CD25(+) T cells and reduced abilities to migrate and promote the proliferation of CD4(+) T cells, which is associated with the upregulation of endogenous transforming growth factor (TGF)-β-mediated indoleamine 2,3-dioxygenase (IDO) expression. Collectively, paeoniflorin could program immature dendritic cells (imDCs) and imDCs stimulated with LPS toward a regulatory DC fate by upregulating the endogenous TGF-β-mediated IDO expression level, thereby demonstrating its potential as a specific immunosuppressive drug.

  9. Immunometabolism governs dendritic cell and macrophage function

    PubMed Central

    2016-01-01

    Recent studies on intracellular metabolism in dendritic cells (DCs) and macrophages provide new insights on the functioning of these critical controllers of innate and adaptive immunity. Both cell types undergo profound metabolic reprogramming in response to environmental cues, such as hypoxia or nutrient alterations, but importantly also in response to danger signals and cytokines. Metabolites such as succinate and citrate have a direct impact on the functioning of macrophages. Immunogenicity and tolerogenicity of DCs is also determined by anabolic and catabolic processes, respectively. These findings provide new prospects for therapeutic manipulation in inflammatory diseases and cancer. PMID:26694970

  10. Dendritic cells during Epstein Barr virus infection

    PubMed Central

    Christian, Münz

    2014-01-01

    Epstein Barr virus (EBV) causes persistent infection in more than 90% of the human adult population and is associated with 2% of all tumors in humans. This γ-herpes virus infects primarily human B and epithelial cells, but it has been reported to be sensed by dendritic cells (DCs) during primary infection. These activated DCs are thought to contribute to innate restriction of EBV infection and initiate EBV-specific adaptive immune responses via cross-priming. The respective evidence and their potential importance for EBV-specific vaccine development will be discussed in this review. PMID:24999343

  11. Stratum corneum targeting by dendritic core-multishell-nanocarriers in a mouse model of psoriasis.

    PubMed

    Pischon, Hannah; Radbruch, Moritz; Ostrowski, Anja; Volz, Pierre; Gerecke, Christian; Unbehauen, Michael; Hönzke, Stefan; Hedtrich, Sarah; Fluhr, Joachim W; Haag, Rainer; Kleuser, Burkhard; Alexiev, Ulrike; Gruber, Achim D; Mundhenk, Lars

    2017-01-01

    Inflammatory disorders of the skin pose particular therapeutic challenges due to complex structural and functional alterations of the skin barrier. Penetration of several anti-inflammatory drugs is particularly problematic in psoriasis, a common dermatitis condition with epidermal hyperplasia and hyperkeratosis. Here, we tested in vivo dermal penetration and biological effects of dendritic core-multishell-nanocarriers (CMS) in a murine skin model of psoriasis and compared it to healthy skin. In both groups, CMS exclusively localized to the stratum corneum of the epidermis with only very sporadic uptake by Langerhans cells. Furthermore, penetration into the viable epidermis of nile red as a model for lipophilic compounds was enhanced by CMS. CMS proved fully biocompatible in several in vitro assays and on normal and psoriatic mouse skin. The observations support the concept of CMS as promising candidates for drug delivery in inflammatory hyperkeratotic skin disorders in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. 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

  13. [Dendritic cells in cancer immunotherapy].

    PubMed

    Gato, M; Liechtenstein, T; Blanco-Luquín, I; Zudaire, M I; Kochan, G; Escors, D

    2015-01-01

    Since the beginning of the 20th century, biomedical scientists have tried to take advantage of the natural anti-cancer activities of the immune system. However, all the scientific and medical efforts dedicated to this have not resulted in the expected success. In fact, classical antineoplastic treatments such as surgery, radio and chemotherapy are still first line treatments. Even so, there is a quantity of experimental evidence demonstrating that cancer cells are immunogenic. However, the effective activation of anti-cancer T cell responses closely depends on an efficient antigen presentation carried out by professional antigen presenting cells such as DC. Although there are a number of strategies to strengthen antigen presentation by DC, anti-cancer immunotherapy is not as effective as we would expect according to preclinical data accumulated in recent decades. We do not aim to make an exhaustive review of DC immunotherapy here, which is an extensive research subject already dealt with in many specialised reviews. Instead, we present the experimental approaches undertaken by our group over the last decade, by modifying DC to improve their anti-tumour capacities.

  14. 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.

  15. Lipopolysaccharide-pretreated plasmacytoid dendritic cells ameliorate experimental chronic kidney disease.

    PubMed

    Zheng, Dong; Cao, Qi; Lee, Vincent W S; Wang, Ya; Zheng, Guoping; Wang, YuanMin; Tan, Thian Kui; Wang, Changqi; Alexander, Stephen I; Harris, David C H; Wang, Yiping

    2012-05-01

    Plasmacytoid dendritic cells play important roles in inducing immune tolerance, preventing allograft rejection, and regulating immune responses in both autoimmune disease and graft-versus-host disease. In order to evaluate a possible protective effect of plasmacytoid dendritic cells against renal inflammation and injury, we purified these cells from mouse spleens and adoptively transferred lipopolysaccharide (LPS)-treated cells, modified ex vivo, into mice with adriamycin nephropathy. These LPS-treated cells localized to the kidney cortex and the lymph nodes draining the kidney, and protected the kidney from injury during adriamycin nephropathy. Glomerulosclerosis, tubular atrophy, interstitial expansion, proteinuria, and creatinine clearance were significantly reduced in mice with adriamycin nephropathy subsequently treated with LPS-activated plasmacytoid dendritic cells as compared to the kidney injury in mice given naive plasmacytoid dendritic cells. In addition, LPS-pretreated cells, but not naive plasmacytoid dendritic cells, convert CD4+CD25- T cells into Foxp3+ regulatory T cells and suppress the proinflammatory cytokine production of endogenous renal macrophages. This may explain their ability to protect against renal injury in adriamycin nephropathy.

  16. Lipid antigen presentation through CD1d pathway in mouse lung epithelial cells, macrophages and dendritic cells and its suppression by poly-dispersed single-walled carbon nanotubes.

    PubMed

    Rizvi, Zaigham Abbas; Puri, Niti; Saxena, Rajiv K

    2015-09-01

    Effect of poly-dispersed acid-functionalized single-walled carbon nanotubes (AF-SWCNTs) was examined on lipid antigen presentation through CD1d pathway on three cell lines, LA4, MHS, and JAWSII used as prototype antigen presenting cells (APCs). CD1d molecule was expressed on 80-90% MHS (prototype macrophages) and JAWSII (prototype dendritic cells) cells whereas <5% LA4 cells (lung epithelial cells, non-classical APCs) expressed CD1d. Treatment with AF-SWCNTs but not with pristine SWCNTs resulted in a significant decline in the level of CD1d mRNA as well as mRNA levels of some other intracellular proteins involved in lipid antigen presentation pathway (MTP, ApoE, prosaposin, SR-BI and LDLr). Lipid antigen presentation was assessed by first incubating the cells with a prototype lipid antigen (α-Glactosylceramide or αGC) and then staining with L363 monoclonal antibody that detects αGC bound to CD1d molecule. While 100% MHS and JAWSII cells presented αGC, only 20% LA4 cells presented the CD1d antigen. Treatment with AF-SWCNTs resulted in a 30-40% decrease in αGC antigen presentation in all three cell lines. These results show that AF-SWCNT treatment down regulated the lipid antigen presentation pathway in all three cell lines and significantly lowered the ability of these cell lines to present αGC antigen.

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

    PubMed

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

    2015-07-01

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

  18. 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.

  19. Macrophages, dendritic cells, and regression of atherosclerosis

    PubMed Central

    Feig, Jonathan E.; Feig, Jessica L.

    2012-01-01

    Atherosclerosis is the number one cause of death in the Western world. It results from the interaction between modified lipoproteins and cells such as macrophages, dendritic cells (DCs), T cells, and other cellular elements present in the arterial wall. This inflammatory process can ultimately lead to the development of complex lesions, or plaques, that protrude into the arterial lumen. Ultimately, plaque rupture and thrombosis can occur leading to the clinical complications of myocardial infarction or stroke. Although each of the cell types plays roles in the pathogenesis of atherosclerosis, the focus of this review will be primarily on the macrophages and DCs. The role of these two cell types in atherosclerosis is discussed, with a particular emphasis on their involvement in atherosclerosis regression. PMID:22934038

  20. Homophilic Protocadherin Cell-Cell Interactions Promote Dendrite Complexity.

    PubMed

    Molumby, Michael J; Keeler, Austin B; Weiner, Joshua A

    2016-05-03

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

  1. Characterization of murine lung dendritic cells: similarities to Langerhans cells and thymic dendritic cells

    PubMed Central

    1990-01-01

    Dendritic cells (DC) are potent accessory cells (AC) for the initiation of primary immune responses. Although murine lymphoid DC and Langerhans cells have been extensively characterized, DC from murine lung have been incompletely described. We isolated cells from enzyme-digested murine lungs and bronchoalveolar lavages that were potent stimulators of a primary mixed lymphocyte response (MLR). The AC had a low buoyant density, were loosely adherent and nonphagocytic. AC function was unaffected by depletion of cells expressing the splenic DC marker, 33D1. In addition, antibody and complement depletion of cells bearing the macrophage marker F4/80, or removal of phagocytic cells with silica also failed to decrease AC activity. In contrast, AC function was decreased by depletion of cells expressing the markers J11d and the low affinity interleukin 2 receptor (IL-2R), both present on thymic and skin DC. AC function was approximately equal in FcR+ and FcR- subpopulations, indicating there was heterogeneity within the AC population. Consistent with the functional data, a combined two-color immunofluorescence and latex bead uptake technique revealed that lung cells high in AC activity were enriched in brightly Ia+ dendritic- shaped cells that (a) were nonphagocytic, (b) lacked specific T and B lymphocyte markers and the macrophage marker F4/80, but (c) frequently expressed C3biR, low affinity IL-2R, FcRII, and the markers NLDC-145 and J11d. Taken together, the functional and phenotypic data suggest the lung cells that stimulate resting T cells in an MLR and that might be important in local pulmonary immune responses are DC that bear functional and phenotypic similarity to other tissues DC, such as Langerhans cells and thymic DC. PMID:2162904

  2. Probiotics, dendritic cells and bladder cancer.

    PubMed

    Feyisetan, Oladapo; Tracey, Christopher; Hellawell, Giles O

    2012-06-01

    What's known on the subject? and What does the study add? The suppressor effect of probiotics on superficial bladder cancer is an observed phenomenon but the specific mechanism is poorly understood. The evidence strongly suggests natural killer (NK) cells are the anti-tumour effector cells involved and NK cell activity correlates with the observed anti-tumour effect in mice. It is also known that dendritic cells (DC) cells are responsible for the recruitment and mobilization of NK cells so therefore it may be inferred that DC cells are most likely to be the interphase point at which probiotics act. In support of this, purification of NK cells was associated with a decrease in NK cells activity. The current use of intravesical bacille Calmette-Guérin in the management of superficial bladder cancer is based on the effect of a localised immune response. In the same way, understanding the mechanism of action of probiotics and the role of DC may potentially offer another avenue via which the immune system may be manipulated to resist bladder cancer. Probiotic foods have been available in the UK since 1996 with the arrival of the fermented milk drink (Yakult) from Japan. The presence of live bacterial ingredients (usually lactobacilli species) may confer health benefits when present in sufficient numbers. The role of probiotics in colo-rectal cancer may be related in part to the suppression of harmful colonic bacteria but other immune mechanisms are involved. Anti-cancer effects outside the colon were suggested by a Japanese report of altered rates of bladder tumour recurrence after ingestion of a particular probiotic. Dendritic cells play a central role to the general regulation of the immune response that may be modified by probiotics. The addition of probiotics to the diet may confer benefit by altering rates of bladder tumour recurrence and also alter the response to immune mechanisms involved with the application of intravesical treatments (bacille Calmette-Guérin).

  3. Metamaterial absorber with random dendritic cells

    NASA Astrophysics Data System (ADS)

    Zhu, Weiren; Zhao, Xiaopeng

    2010-05-01

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

  4. Anomalous diffusion in Purkinje cell dendrites caused by spines

    PubMed Central

    Santamaria, Fidel; Wils, Stefan; De Schutter, Erik; Augustine, George J.

    2007-01-01

    We combined local photolysis of caged compounds with fluorescence imaging to visualize molecular diffusion within dendrites of cerebellar Purkinje cells. Diffusion of a volume marker, fluorescein dextran, within spiny dendrites was remarkably slow in comparison to its diffusion in smooth dendrites. Computer simulations indicate that this retardation is due to a transient trapping of molecules within dendritic spines, yielding anomalous diffusion. We considered the influence of spine trapping on the diffusion of calcium ions (Ca2+) and inositol-1,4,5-triphospate (IP3), two synaptic second messengers. Diffusion of IP3 was strongly influenced by the presence of dendritic spines while Ca2+ was removed so rapidly that it could not diffuse far enough to be trapped. We conclude that an important function of dendritic spines may be to trap chemical signals and thereby create slowed anomalous diffusion within dendrites. PMID:17114048

  5. Hematologic neoplasms: Dendritic cells vaccines in motion.

    PubMed

    Galati, Domenico; Zanotta, Serena

    2017-09-11

    Dendritic cells (DCs) are bone-marrow-derived immune cells accounted for a key role in cancer vaccination as potent antigen-presenting cells within the immune system. Cancer microenvironment can modulate DCs maturation resulting in their accumulation into functional states associated with a reduced antitumor immune response. In this regard, a successful cancer vaccine needs to mount a potent antitumor immune response able to overcome the immunosuppressive tumor milieu. As a consequence, DCs-based approaches are a safe and promising strategy for improving the therapeutic efficacy in hematological malignancies, particularly in combinations with additional treatments. This review summarizes the most significant evidence about the immunotherapeutic strategies performed to target hematologic neoplasms including the tumoral associated antigens (TAA) pulsed on DCs, whole tumor cell vaccines or leukemia-derived DCs. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. 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.

  7. 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.

  8. Lamin B1 protein is required for dendrite development in primary mouse cortical neurons.

    PubMed

    Giacomini, Caterina; Mahajani, Sameehan; Ruffilli, Roberta; Marotta, Roberto; Gasparini, Laura

    2016-01-01

    Lamin B1, a key component of the nuclear lamina, plays an important role in brain development and function. A duplication of the human lamin B1 (LMNB1) gene has been linked to adult-onset autosomal dominant leukodystrophy, and mouse and human loss-of-function mutations in lamin B1 are susceptibility factors for neural tube defects. In the mouse, experimental ablation of endogenous lamin B1 (Lmnb1) severely impairs embryonic corticogenesis. Here we report that in primary mouse cortical neurons, LMNB1 overexpression reduces axonal outgrowth, whereas deficiency of endogenous Lmnb1 results in aberrant dendritic development. In the absence of Lmnb1, both the length and complexity of dendrites are reduced, and their growth is unresponsive to KCl stimulation. This defective dendritic outgrowth stems from impaired ERK signaling. In Lmnb1-null neurons, ERK is correctly phosphorylated, but phospho-ERK fails to translocate to the nucleus, possibly due to delocalization of nuclear pore complexes (NPCs) at the nuclear envelope. Taken together, these data highlight a previously unrecognized role of lamin B1 in dendrite development of mouse cortical neurons through regulation of nuclear shuttling of specific signaling molecules and NPC distribution.

  9. Lamin B1 protein is required for dendrite development in primary mouse cortical neurons

    PubMed Central

    Giacomini, Caterina; Mahajani, Sameehan; Ruffilli, Roberta; Marotta, Roberto; Gasparini, Laura

    2016-01-01

    Lamin B1, a key component of the nuclear lamina, plays an important role in brain development and function. A duplication of the human lamin B1 (LMNB1) gene has been linked to adult-onset autosomal dominant leukodystrophy, and mouse and human loss-of-function mutations in lamin B1 are susceptibility factors for neural tube defects. In the mouse, experimental ablation of endogenous lamin B1 (Lmnb1) severely impairs embryonic corticogenesis. Here we report that in primary mouse cortical neurons, LMNB1 overexpression reduces axonal outgrowth, whereas deficiency of endogenous Lmnb1 results in aberrant dendritic development. In the absence of Lmnb1, both the length and complexity of dendrites are reduced, and their growth is unresponsive to KCl stimulation. This defective dendritic outgrowth stems from impaired ERK signaling. In Lmnb1-null neurons, ERK is correctly phosphorylated, but phospho-ERK fails to translocate to the nucleus, possibly due to delocalization of nuclear pore complexes (NPCs) at the nuclear envelope. Taken together, these data highlight a previously unrecognized role of lamin B1 in dendrite development of mouse cortical neurons through regulation of nuclear shuttling of specific signaling molecules and NPC distribution. PMID:26510501

  10. Harnessing Human Dendritic Cell Subsets for Medicine

    PubMed Central

    Ueno, Hideki; Schmitt, Nathalie; Klechevsky, Eynav; Pedroza-Gonzales, Alexander; Matsui, Toshimichi; Zurawski, Gerard; Oh, SangKon; Fay, Joseph; Pascual, Virginia; Banchereau, Jacques; Palucka, Karolina

    2010-01-01

    Summary Immunity results from a complex interplay between the antigen-nonspecific innate immune system and the antigen-specific adaptive immune system. The cells and molecules of the innate system employ non-clonal recognition receptors including lectins, Toll-like receptors, NOD-like receptors and helicases. B and T lymphocytes of the adaptive immune system employ clonal receptors recognizing antigens or their derived peptides in a highly specific manner. An essential link between innate and adaptive immunity is provided by dendritic cells (DCs). DCs can induce such contrasting states as immunity and tolerance. The recent years have brought a wealth of information on the biology of DCs revealing the complexity of this cell system. Indeed, DC plasticity and subsets are prominent determinants of the type and quality of elicited immune responses. Here we summarize our recent studies aimed at a better understanding of the DC system to unravel the pathophysiology of human diseases and design novel human vaccines. PMID:20193020

  11. Blood monocytes: development, heterogeneity, and relationship with dendritic cells.

    PubMed

    Auffray, Cedric; Sieweke, Michael H; Geissmann, Frederic

    2009-01-01

    Monocytes are circulating blood leukocytes that play important roles in the inflammatory response, which is essential for the innate response to pathogens. But inflammation and monocytes are also involved in the pathogenesis of inflammatory diseases, including atherosclerosis. In adult mice, monocytes originate in the bone marrow in a Csf-1R (MCSF-R, CD115)-dependent manner from a hematopoietic precursor common for monocytes and several subsets of macrophages and dendritic cells (DCs). Monocyte heterogeneity has long been recognized, but in recent years investigators have identified three functional subsets of human monocytes and two subsets of mouse monocytes that exert specific roles in homeostasis and inflammation in vivo, reminiscent of those of the previously described classically and alternatively activated macrophages. Functional characterization of monocytes is in progress in humans and rodents and will provide a better understanding of the pathophysiology of inflammation.

  12. Dendritic epidermal T cells facilitate wound healing in diabetic mice

    PubMed Central

    Liu, Zhongyang; Xu, Yingbin; Chen, Lei; Xie, Julin; Tang, Jinming; Zhao, Jingling; Shu, Bin; Qi, Shaohai; Chen, Jian; Liang, Guangping; Luo, Gaoxing; Wu, Jun; He, Weifeng; Liu, Xusheng

    2016-01-01

    The impairment of skin repair in diabetic patients can lead to increased morbidity and mortality. Proper proliferation, apoptosis and migration in keratinocytes are vital for skin repair, but in diabetic patients, hyperglycemia impairs this process. Dendritic epidermal T cells (DETCs) are an important part of the resident cutaneous immunosurveillance program. We observed a reduction in the number of DETCs in a streptozotocin-induced diabetic mouse model. This reduction in DETCs resulted in decreased IGF-1 and KGF production in the epidermis, which is closely associated with diabetic delayed wound closure. DETCs ameliorated the poor wound-healing conditions in diabetic mice by increasing keratinocyte migration and proliferation and decreasing keratinocyte apoptosis in diabetes-like microenvironments. Our results elucidate a new mechanism for diabetic delayed wound closure and point to a new strategy for the treatment of wounds in diabetic patients. PMID:27347345

  13. Plasmacytoid Dendritic Cells and the Control of Herpesvirus Infections

    PubMed Central

    Baranek, Thomas; Zucchini, Nicolas; Dalod, Marc

    2009-01-01

    Type-I interferons (IFN-I) are cytokines essential for vertebrate antiviral defense, including against herpesviruses. IFN-I have potent direct antiviral activities and also mediate a multiplicity of immunoregulatory functions, which can either promote or dampen antiviral adaptive immune responses. Plasmacytoid dendritic cells (pDCs) are the professional producers of IFN-I in response to many viruses, including all of the herpesviruses tested. There is strong evidence that pDCs could play a major role in the initial orchestration of both innate and adaptive antiviral immune responses. Depending on their activation pattern, pDC responses may be either protective or detrimental to the host. Here, we summarize and discuss current knowledge regarding pDC implication in the physiopathology of mouse and human herpesvirus infections, and we discuss how pDC functions could be manipulated in immunotherapeutic settings to promote health over disease. PMID:21994554

  14. Visualization and genetic manipulation of dendrites and spines in the mouse cerebral cortex and hippocampus using in utero electroporation.

    PubMed

    Pacary, Emilie; Haas, Matilda A; Wildner, Hendrik; Azzarelli, Roberta; Bell, Donald M; Abrous, Djoher Nora; Guillemot, François

    2012-07-26

    In utero electroporation (IUE) has become a powerful technique to study the development of different regions of the embryonic nervous system (1-5). To date this tool has been widely used to study the regulation of cellular proliferation, differentiation and neuronal migration especially in the developing cerebral cortex (6-8). Here we detail our protocol to electroporate in utero the cerebral cortex and the hippocampus and provide evidence that this approach can be used to study dendrites and spines in these two cerebral regions. Visualization and manipulation of neurons in primary cultures have contributed to a better understanding of the processes involved in dendrite, spine and synapse development. However neurons growing in vitro are not exposed to all the physiological cues that can affect dendrite and/or spine formation and maintenance during normal development. Our knowledge of dendrite and spine structures in vivo in wild-type or mutant mice comes mostly from observations using the Golgi-Cox method( 9). However, Golgi staining is considered to be unpredictable. Indeed, groups of nerve cells and fiber tracts are labeled randomly, with particular areas often appearing completely stained while adjacent areas are devoid of staining. Recent studies have shown that IUE of fluorescent constructs represents an attractive alternative method to study dendrites, spines as well as synapses in mutant / wild-type mice (10-11) (Figure 1A). Moreover in comparison to the generation of mouse knockouts, IUE represents a rapid approach to perform gain and loss of function studies in specific population of cells during a specific time window. In addition, IUE has been successfully used with inducible gene expression or inducible RNAi approaches to refine the temporal control over the expression of a gene or shRNA (12). These advantages of IUE have thus opened new dimensions to study the effect of gene expression/suppression on dendrites and spines not only in specific cerebral

  15. Visualization and Genetic Manipulation of Dendrites and Spines in the Mouse Cerebral Cortex and Hippocampus using In utero Electroporation

    PubMed Central

    Pacary, Emilie; Haas, Matilda A.; Wildner, Hendrik; Azzarelli, Roberta; Bell, Donald M.; Abrous, Djoher Nora; Guillemot, François

    2012-01-01

    In utero electroporation (IUE) has become a powerful technique to study the development of different regions of the embryonic nervous system 1-5. To date this tool has been widely used to study the regulation of cellular proliferation, differentiation and neuronal migration especially in the developing cerebral cortex 6-8. Here we detail our protocol to electroporate in utero the cerebral cortex and the hippocampus and provide evidence that this approach can be used to study dendrites and spines in these two cerebral regions. Visualization and manipulation of neurons in primary cultures have contributed to a better understanding of the processes involved in dendrite, spine and synapse development. However neurons growing in vitro are not exposed to all the physiological cues that can affect dendrite and/or spine formation and maintenance during normal development. Our knowledge of dendrite and spine structures in vivo in wild-type or mutant mice comes mostly from observations using the Golgi-Cox method 9. However, Golgi staining is considered to be unpredictable. Indeed, groups of nerve cells and fiber tracts are labeled randomly, with particular areas often appearing completely stained while adjacent areas are devoid of staining. Recent studies have shown that IUE of fluorescent constructs represents an attractive alternative method to study dendrites, spines as well as synapses in mutant / wild-type mice 10-11 (Figure 1A). Moreover in comparison to the generation of mouse knockouts, IUE represents a rapid approach to perform gain and loss of function studies in specific population of cells during a specific time window. In addition, IUE has been successfully used with inducible gene expression or inducible RNAi approaches to refine the temporal control over the expression of a gene or shRNA 12. These advantages of IUE have thus opened new dimensions to study the effect of gene expression/suppression on dendrites and spines not only in specific cerebral structures

  16. Langerhans cells and dermal dendritic cells capture protein antigens in the skin: Possible targets for vaccination through the skin

    PubMed Central

    Sparber, Florian; Tripp, Christoph H.; Hermann, Martin; Romani, Nikolaus; Stoitzner, Patrizia

    2010-01-01

    Dendritic cells capture and process antigen and present it to T lymphocytes in the lymphoid organs. Dendritic cells of the skin, including epidermal Langerhans cells, langerin+ and langerinnegative dermal dendritic cells are ideally positioned to take up pathogens that enter the body through the skin or vaccines that are administered into (intradermal) or onto (epicutaneous) the skin. The antigen uptake properties of skin dendritic cells have not thoroughly been studied yet. We therefore investigated the uptake of the fluorochrome-conjugated model antigen ovalbumin (OVA) by skin dendritic cells in the mouse. OVA was readily taken up by immature Langerhans cells both in situ and in cell suspensions. When offered to Langerhans cells in situ either by “bathing” skin explants in OVA-containing culture medium or by intradermal injection they retained the captured OVA for at least 2–3 days when migrating into the culture medium and, importantly, into the draining lymph nodes. Also langerin+ and – to a larger extent – langerinnegative skin dendritic cells took up and transported OVA to the lymph nodes. Interestingly, mature Langerhans cells were still capable of ingesting substantial amounts of OVA, indicating that predominantly receptor-mediated endocytosis is operative in these cells. Unlike macropinocytosis, this pathway of endocytosis is not shut down upon dendritic cell maturation. These observations indicate that in intradermal vaccination schemes, Langerhans cells from the epidermis are prominently involved. They were recently shown to possess the capacity to induce functional cytotoxic T lymphocytes. Furthermore, the potential to markedly enhance antigen uptake and processing by targeting antigen to c-type lectin receptors on Langerhans cells was also recently demonstrated. Our data provide a rationale and an incentive to explore in more detail antigen targeting to Langerhans cells with the aim of harnessing it for immunotherapy. PMID:20599290

  17. Plasmacytoid dendritic cells are crucial in Bifidobacterium adolescentis-mediated inhibition of Yersinia enterocolitica infection.

    PubMed

    Wittmann, Alexandra; Autenrieth, Ingo B; Frick, Julia-Stefanie

    2013-01-01

    In industrialized countries bacterial intestinal infections are commonly caused by enteropathogenic Enterobacteriaceae. The interaction of the microbiota with the host immune system determines the adequacy of an appropriate response against pathogens. In this study we addressed whether the probiotic Bifidobacterium adolescentis is protective during intestinal Yersinia enterocolitica infection. Female C57BL/6 mice were fed with B. adolescentis, infected with Yersinia enterocolitica, or B. adolescentis fed and subsequently infected with Yersinia enterocolitica. B. adolescentis fed and Yersinia infected mice were protected from Yersinia infection as indicated by a significantly reduced weight loss and splenic Yersinia load when compared to Yersinia infected mice. Moreover, protection from infection was associated with increased intestinal plasmacytoid dendritic cell and regulatory T-cell frequencies. Plasmacytoid dendritic cell function was investigated using depletion experiments by injecting B. adolescentis fed, Yersinia infected C57BL/6 mice with anti-mouse PDCA-1 antibody, to deplete plasmacytoid dendritic cells, or respective isotype control. The B. adolescentis-mediated protection from Yersinia dissemination to the spleen was abrogated after plasmacytoid dendritic cell depletion indicating a crucial function for pDC in control of intestinal Yersinia infection. We suggest that feeding of B. adolescentis modulates the intestinal immune system in terms of increased plasmacytoid dendritic cell and regulatory T-cell frequencies, which might account for the B. adolescentis-mediated protection from Yersinia enterocolitica infection.

  18. Plasmacytoid Dendritic Cells Are Crucial in Bifidobacterium adolescentis-Mediated Inhibition of Yersinia enterocolitica Infection

    PubMed Central

    Wittmann, Alexandra; Autenrieth, Ingo B.; Frick, Julia-Stefanie

    2013-01-01

    In industrialized countries bacterial intestinal infections are commonly caused by enteropathogenic Enterobacteriaceae. The interaction of the microbiota with the host immune system determines the adequacy of an appropriate response against pathogens. In this study we addressed whether the probiotic Bifidobacterium adolescentis is protective during intestinal Yersinia enterocolitica infection. Female C57BL/6 mice were fed with B. adolescentis, infected with Yersinia enterocolitica, or B. adolescentis fed and subsequently infected with Yersinia enterocolitica. B. adolescentis fed and Yersinia infected mice were protected from Yersinia infection as indicated by a significantly reduced weight loss and splenic Yersinia load when compared to Yersinia infected mice. Moreover, protection from infection was associated with increased intestinal plasmacytoid dendritic cell and regulatory T-cell frequencies. Plasmacytoid dendritic cell function was investigated using depletion experiments by injecting B. adolescentis fed, Yersinia infected C57BL/6 mice with anti-mouse PDCA-1 antibody, to deplete plasmacytoid dendritic cells, or respective isotype control. The B. adolescentis-mediated protection from Yersinia dissemination to the spleen was abrogated after plasmacytoid dendritic cell depletion indicating a crucial function for pDC in control of intestinal Yersinia infection. We suggest that feeding of B. adolescentis modulates the intestinal immune system in terms of increased plasmacytoid dendritic cell and regulatory T-cell frequencies, which might account for the B. adolescentis-mediated protection from Yersinia enterocolitica infection. PMID:23977019

  19. Dendritic cell control of tolerogenic responses

    PubMed Central

    Manicassamy, Santhakumar; Pulendran, Bali

    2011-01-01

    Summary One of the most fundamental problems in immunology is the seemingly schizophrenic ability of the immune system to launch robust immunity against pathogens, while acquiring and maintaining a state of tolerance to the body’s own tissues and the trillions of commensal microorganisms and food antigens that confront it every day. A fundamental role for the innate immune system, particularly dendritic cells (DCs), in orchestrating immunological tolerance has been appreciated, but emerging studies have highlighted the nature of the innate receptors and the signaling pathways that program DCs to a tolerogenic state. Furthermore, several studies have emphasized the major role played by cellular interactions, and the microenvironment in programming tolerogenic DCs. Here we review these studies and suggest that the innate control of tolerogenic responses can be viewed as different hierarchies of organization, in which DCs, their innate receptors and signaling networks, and their interactions with other cells and local microenvironments represent different levels of the hierarchy. PMID:21488899

  20. Dendritic cell vaccination in acute myeloid leukemia.

    PubMed

    Anguille, Sébastien; Willemen, Yannick; Lion, Eva; Smits, Evelien L; Berneman, Zwi N

    2012-07-01

    The prognosis of patients with acute myeloid leukemia (AML) remains dismal, with a 5-year overall survival rate of only 5.2% for the continuously growing subgroup of AML patients older than 65 years. These patients are generally not considered eligible for intensive chemotherapy and/or allogeneic hematopoietic stem cell transplantation because of high treatment-related morbidity and mortality, emphasizing the need for novel, less toxic, treatment alternatives. It is within this context that immunotherapy has gained attention in recent years. In this review, we focus on the use of dendritic cell (DC) vaccines for immunotherapy of AML. DC are central orchestrators of the immune system, bridging innate and adaptive immunity and critical to the induction of anti-leukemic immunity. We discuss the rationale and basic principles of DC-based therapy for AML and review the clinical experience that has been obtained so far with this form of immunotherapy for patients with AML.

  1. 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

  2. Transcriptional Control of Dendritic Cell Development

    PubMed Central

    Murphy, Theresa L.; Grajales-Reyes, Gary E.; Wu, Xiaodi; Tussiwand, Roxane; Briseño, Carlos G.; Iwata, Arifumi; Kretzer, Nicole M.; Durai, Vivek; Murphy, Kenneth M.

    2016-01-01

    The dendritic cells (DCs) of the immune system function in innate and adaptive responses by directing activity of various effector cells rather than serving as effectors themselves. DCs and closely related myeloid lineages share expression of many surface receptors, presenting a challenge in distinguishing their unique in vivo functions. Recent work has taken advantage of unique transcriptional programs to identify and manipulate murine DCs in vivo. This work has assigned several nonredundant in vivo functions to distinct DC lineages, consisting of plasmacytoid DCs and several subsets of classical DCs that promote different immune effector modules in response to pathogens. In parallel, a correspondence between human and murine DC subsets has emerged, underlying structural similarities for the DC lineages between these species. Recent work has begun to unravel the transcriptional circuitry that controls the development and diversification of DCs from common progenitors in the bone marrow. PMID:26735697

  3. 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.

  4. Dendritic cells and immunity against cancer

    PubMed Central

    Palucka, Karolina; Ueno, Hideki; Fay, Joseph; Banchereau, Jacques

    2010-01-01

    SUMMARY T cells can reject established tumors when adoptively transferred into patients, thereby demonstrating the power of the immune system for cancer therapy. However, it has proven difficult to maintain adoptively transferred T cells in the long term. Vaccines have the potential to induce tumor-specific effector and memory T cells. However, clinical efficacy of current vaccines is limited, possibly because tumors skew the immune system by means of myeloid-derived suppressor cells, inflammatory type 2 T cells and regulatory T cells (Tregs), all of which prevent the generation of effector cells. To improve the clinical efficacy of cancer vaccines in patients with metastatic disease, we need to design novel and improved strategies that can boost adaptive immunity to cancer, help overcome Tregs and allow the breakdown of the immunosuppressive tumor microenvironment. This can be achieved by exploiting the fast increasing knowledge about the dendritic cell (DC) system, including the existence of distinct DC subsets which respond differentially to distinct activation signals, (functional plasticity), both contributing to the generation of unique adaptive immune responses. We foresee that these novel cancer vaccines will be used as monotherapy in patients with resected disease, and in combination with drugs targeting regulatory/suppressor pathways in patients with metastatic disease. PMID:21158979

  5. 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

  6. GATA2 regulates dendritic cell differentiation

    PubMed Central

    Onodera, Koichi; Fujiwara, Tohru; Onishi, Yasushi; Itoh-Nakadai, Ari; Okitsu, Yoko; Fukuhara, Noriko; Ishizawa, Kenichi; Shimizu, Ritsuko; Yamamoto, Masayuki

    2016-01-01

    Dendritic cells (DCs) are critical immune response regulators; however, the mechanism of DC differentiation is not fully understood. Heterozygous germ line GATA2 mutations induce GATA2-deficiency syndrome, characterized by monocytopenia, a predisposition to myelodysplasia/acute myeloid leukemia, and a profoundly reduced DC population, which is associated with increased susceptibility to viral infections, impaired phagocytosis, and decreased cytokine production. To define the role of GATA2 in DC differentiation and function, we studied Gata2 conditional knockout and haploinsufficient mice. Gata2 conditional deficiency significantly reduced the DC count, whereas Gata2 haploinsufficiency did not affect this population. GATA2 was required for the in vitro generation of DCs from Lin−Sca-1+Kit+ cells, common myeloid-restricted progenitors, and common dendritic cell precursors, but not common lymphoid-restricted progenitors or granulocyte-macrophage progenitors, suggesting that GATA2 functions in the myeloid pathway of DC differentiation. Moreover, expression profiling demonstrated reduced expression of myeloid-related genes, including mafb, and increased expression of T-lymphocyte–related genes, including Gata3 and Tcf7, in Gata2-deficient DC progenitors. In addition, GATA2 was found to bind an enhancer element 190-kb downstream region of Gata3, and a reporter assay exhibited significantly reduced luciferase activity after adding this enhancer region to the Gata3 promoter, which was recovered by GATA sequence deletion within Gata3 +190. These results suggest that GATA2 plays an important role in cell-fate specification toward the myeloid vs T-lymphocyte lineage by regulating lineage-specific transcription factors in DC progenitors, thereby contributing to DC differentiation. PMID:27259979

  7. GATA2 regulates dendritic cell differentiation.

    PubMed

    Onodera, Koichi; Fujiwara, Tohru; Onishi, Yasushi; Itoh-Nakadai, Ari; Okitsu, Yoko; Fukuhara, Noriko; Ishizawa, Kenichi; Shimizu, Ritsuko; Yamamoto, Masayuki; Harigae, Hideo

    2016-07-28

    Dendritic cells (DCs) are critical immune response regulators; however, the mechanism of DC differentiation is not fully understood. Heterozygous germ line GATA2 mutations induce GATA2-deficiency syndrome, characterized by monocytopenia, a predisposition to myelodysplasia/acute myeloid leukemia, and a profoundly reduced DC population, which is associated with increased susceptibility to viral infections, impaired phagocytosis, and decreased cytokine production. To define the role of GATA2 in DC differentiation and function, we studied Gata2 conditional knockout and haploinsufficient mice. Gata2 conditional deficiency significantly reduced the DC count, whereas Gata2 haploinsufficiency did not affect this population. GATA2 was required for the in vitro generation of DCs from Lin(-)Sca-1(+)Kit(+) cells, common myeloid-restricted progenitors, and common dendritic cell precursors, but not common lymphoid-restricted progenitors or granulocyte-macrophage progenitors, suggesting that GATA2 functions in the myeloid pathway of DC differentiation. Moreover, expression profiling demonstrated reduced expression of myeloid-related genes, including mafb, and increased expression of T-lymphocyte-related genes, including Gata3 and Tcf7, in Gata2-deficient DC progenitors. In addition, GATA2 was found to bind an enhancer element 190-kb downstream region of Gata3, and a reporter assay exhibited significantly reduced luciferase activity after adding this enhancer region to the Gata3 promoter, which was recovered by GATA sequence deletion within Gata3 +190. These results suggest that GATA2 plays an important role in cell-fate specification toward the myeloid vs T-lymphocyte lineage by regulating lineage-specific transcription factors in DC progenitors, thereby contributing to DC differentiation.

  8. A Specific Nutrient Combination Attenuates the Reduced Expression of PSD-95 in the Proximal Dendrites of Hippocampal Cell Body Layers in a Mouse Model of Phenylketonuria

    PubMed Central

    Bruinenberg, Vibeke M.; van Vliet, Danique; Attali, Amos; de Wilde, Martijn C.; Kuhn, Mirjam; van Spronsen, Francjan J.; van der Zee, Eddy A.

    2016-01-01

    The inherited metabolic disease phenylketonuria (PKU) is characterized by increased concentrations of phenylalanine in the blood and brain, and as a consequence neurotransmitter metabolism, white matter, and synapse functioning are affected. A specific nutrient combination (SNC) has been shown to improve synapse formation, morphology and function. This could become an interesting new nutritional approach for PKU. To assess whether treatment with SNC can affect synapses, we treated PKU mice with SNC or an isocaloric control diet and wild-type (WT) mice with an isocaloric control for 12 weeks, starting at postnatal day 31. Immunostaining for post-synaptic density protein 95 (PSD-95), a post-synaptic density marker, was carried out in the hippocampus, striatum and prefrontal cortex. Compared to WT mice on normal chow without SNC, PKU mice on the isocaloric control showed a significant reduction in PSD-95 expression in the hippocampus, specifically in the granular cell layer of the dentate gyrus, with a similar trend seen in the cornus ammonis 1 (CA1) and cornus ammonis 3 (CA3) pyramidal cell layer. No differences were found in the striatum or prefrontal cortex. PKU mice on a diet supplemented with SNC showed improved expression of PSD-95 in the hippocampus. This study gives the first indication that SNC supplementation has a positive effect on hippocampal synaptic deficits in PKU mice. PMID:27102170

  9. A Specific Nutrient Combination Attenuates the Reduced Expression of PSD-95 in the Proximal Dendrites of Hippocampal Cell Body Layers in a Mouse Model of Phenylketonuria.

    PubMed

    Bruinenberg, Vibeke M; van Vliet, Danique; Attali, Amos; de Wilde, Martijn C; Kuhn, Mirjam; van Spronsen, Francjan J; van der Zee, Eddy A

    2016-03-26

    The inherited metabolic disease phenylketonuria (PKU) is characterized by increased concentrations of phenylalanine in the blood and brain, and as a consequence neurotransmitter metabolism, white matter, and synapse functioning are affected. A specific nutrient combination (SNC) has been shown to improve synapse formation, morphology and function. This could become an interesting new nutritional approach for PKU. To assess whether treatment with SNC can affect synapses, we treated PKU mice with SNC or an isocaloric control diet and wild-type (WT) mice with an isocaloric control for 12 weeks, starting at postnatal day 31. Immunostaining for post-synaptic density protein 95 (PSD-95), a post-synaptic density marker, was carried out in the hippocampus, striatum and prefrontal cortex. Compared to WT mice on normal chow without SNC, PKU mice on the isocaloric control showed a significant reduction in PSD-95 expression in the hippocampus, specifically in the granular cell layer of the dentate gyrus, with a similar trend seen in the cornus ammonis 1 (CA1) and cornus ammonis 3 (CA3) pyramidal cell layer. No differences were found in the striatum or prefrontal cortex. PKU mice on a diet supplemented with SNC showed improved expression of PSD-95 in the hippocampus. This study gives the first indication that SNC supplementation has a positive effect on hippocampal synaptic deficits in PKU mice.

  10. Dendritic cells and follicular dendritic cells express a novel ligand for CD38 which influences their maturation and antibody responses

    PubMed Central

    Wykes, Michelle N; Beattie, Lynette; MacPherson, Gordon G; Hart, Derek N

    2004-01-01

    CD38 is a cell surface molecule with ADP-ribosyl cyclase activity, which is predominantly expressed on lymphoid and myeloid cells. CD38 has a significant role in B-cell function as some anti-CD38 antibodies can deliver potent growth and differentiation signals, but the ligand that delivers this signal in mice is unknown. We used a chimeric protein of mouse CD38 and human immunogobulin G (IgG) (CD38-Ig) to identify a novel ligand for murine CD38 (CD38L) on networks of follicular dendritic cells (FDCs) as well as dendritic cells (DCs) in the spleen. Flow-cytometry found that all DC subsets expressed cytoplasmic CD38L but only fresh ex vivo CD11c+ CD11b− DCs had cell surface CD38L. Anti-CD38 antibody blocked the binding of CD38-Ig to CD38L, confirming the specificity of detection. CD38-Ig immuno-precipitated ligands of 66 and 130 kDa. Functional studies found that CD38-Ig along with anti-CD40 and anti-major histocompatibility complex (MHC) class II antibody provided maturation signals to DCs in vitro. When CD38-Ig was administered in vivo with antigen, IgG2a responses were significantly reduced, suggesting that B and T cells expressing CD38 may modulate the isotype of antibodies produced through interaction with CD38L on DCs. CD38-Ig also expanded FDC networks when administered in vivo. In conclusion, this study has identified a novel ligand for CD38 which has a role in functional interactions between lymphocytes and DCs or FDCs. PMID:15500618

  11. Harnessing Dendritic Cells to Generate Cancer Vaccines

    PubMed Central

    Palucka, Karolina; Ueno, Hideki; Fay, Joseph; Banchereau, Jacques

    2009-01-01

    Passive immunotherapy of cancer, i.e., transfer of T cells or antibodies, can lead to some objective clinical responses, thus demonstrating that the immune system can reject tumors. However, passive immunotherapy is not expected to yield memory T cells that might control tumor outgrowth. Active immunotherapy with dendritic cell (DCs) vaccines has the potential to induce tumor-specific effector and memory T cells. Clinical trials testing first generation DC vaccines pulsed with tumor antigens provided a proof-of-principle that therapeutic immunity can be elicited. Newer generation DC vaccines are build on the increased knowledge of the DC system including the existence of distinct DC subsets and their plasticity all leading to generation of distinct types of immunity. Rather than the quantity of IFN-γ secreting CD8+ T cells, we should aim at generating high quality high avidity poly-functional effector CD8+ T cells able to reject tumors and long-lived memory CD8+ T cells able to prevent relapse. PMID:19769741

  12. Sensory deprivation differentially impacts the dendritic development of pyramidal versus non-pyramidal neurons in layer 6 of mouse barrel cortex.

    PubMed

    Chen, Chia-Chien; Tam, Danny; Brumberg, Joshua C

    2012-04-01

    Early postnatal sensory experience can have profound impacts on the structure and function of cortical circuits affecting behavior. Using the mouse whisker-to-barrel system we chronically deprived animals of normal sensory experience by bilaterally trimming their whiskers every other day from birth for the first postnatal month. Brain tissue was then processed for Golgi staining and neurons in layer 6 of barrel cortex were reconstructed in three dimensions. Dendritic and somatic parameters were compared between sensory-deprived and normal sensory experience groups. Results demonstrated that layer 6 non-pyramidal neurons in the chronically deprived group showed an expansion of their dendritic arbors. The pyramidal cells responded to sensory deprivation with increased somatic size and basilar dendritic arborization but overall decreased apical dendritic parameters. In sum, sensory deprivation impacted on the neuronal architecture of pyramidal and non-pyramidal neurons in layer 6, which may provide a substrate for observed physiological and behavioral changes resulting from whisker trimming.

  13. Leukotrienes modulate cytokine release from dendritic cells.

    PubMed

    Jozefowski, Szczepan; Biedroń, Rafał; Bobek, Malgorzata; Marcinkiewicz, Janusz

    2005-12-01

    Leukotriene B(4) (LTB(4)) and cysteinyl leukotrienes (CysLTs) are known as potent mediators of inflammation, whereas their role in the regulation of adaptive immunity remains poorly characterized. Dendritic cells (DCs) are specialized antigen-presenting cells, uniquely capable to initiate primary immune responses. We have found that zymosan, but not lipopolysaccharide (LPS) stimulates murine bone marrow-derived dendritic cells (BM-DCs) to produce large amounts of CysLTs and LTB(4) from endogenous substrates. A selective inhibitor of leukotriene synthesis MK886 as well as an antagonist of the high affinity LTB(4) receptor (BLT(1)) U-75302 slightly inhibited zymosan-, but not LPS-stimulated interleukin (IL)-10 release from BM-DCs. In contrast, U-75302 increased zymosan-stimulated release of IL-12 p40 by approximately 23%. Pre-treatment with transforming growth factor-beta1 enhanced both stimulated leukotriene synthesis and the inhibitory effect of U-75302 and MK886 on IL-10 release from DCs. Consistent with the effects of leukotriene antagonists, exogenous LTB(4) enhanced LPS-stimulated IL-10 release by approximately 39% and inhibited IL-12 p40 release by approximately 22%. Both effects were mediated by the BLT(1) receptor. Ligands of the high affinity CysLTs receptor (CysLT(1)), MK-571 and LTD(4) had little or no effect on cytokine release. Agonists of the nuclear LTB(4) receptor peroxisome proliferator-activated receptor-alpha, 8(S)-hydroxyeicosatetraenoic acid and 5,8,11,14-eicosatetraynoic acid, inhibited release of both IL-12 p40 and IL-10. Our results indicate that both autocrine and paracrine leukotrienes may modulate cytokine release from DCs, in a manner that is consistent with previously reported T helper 2-polarizing effects of leukotrienes.

  14. Leukotrienes modulate cytokine release from dendritic cells

    PubMed Central

    Jozefowski, Szczepan; Biedroń, Rafał; Bobek, Malgorzata; Marcinkiewicz, Janusz

    2005-01-01

    Leukotriene B4 (LTB4) and cysteinyl leukotrienes (CysLTs) are known as potent mediators of inflammation, whereas their role in the regulation of adaptive immunity remains poorly characterized. Dendritic cells (DCs) are specialized antigen-presenting cells, uniquely capable to initiate primary immune responses. We have found that zymosan, but not lipopolysaccharide (LPS) stimulates murine bone marrow-derived dendritic cells (BM-DCs) to produce large amounts of CysLTs and LTB4 from endogenous substrates. A selective inhibitor of leukotriene synthesis MK886 as well as an antagonist of the high affinity LTB4 receptor (BLT1) U-75302 slightly inhibited zymosan-, but not LPS-stimulated interleukin (IL)-10 release from BM-DCs. In contrast, U-75302 increased zymosan-stimulated release of IL-12 p40 by ∼23%. Pre-treatment with transforming growth factor-β1 enhanced both stimulated leukotriene synthesis and the inhibitory effect of U-75302 and MK886 on IL-10 release from DCs. Consistent with the effects of leukotriene antagonists, exogenous LTB4 enhanced LPS-stimulated IL-10 release by ∼39% and inhibited IL-12 p40 release by ∼22%. Both effects were mediated by the BLT1 receptor. Ligands of the high affinity CysLTs receptor (CysLT1), MK-571 and LTD4 had little or no effect on cytokine release. Agonists of the nuclear LTB4 receptor peroxisome proliferator-activated receptor-α, 8(S)-hydroxyeicosatetraenoic acid and 5,8,11,14-eicosatetraynoic acid, inhibited release of both IL-12 p40 and IL-10. Our results indicate that both autocrine and paracrine leukotrienes may modulate cytokine release from DCs, in a manner that is consistent with previously reported T helper 2-polarizing effects of leukotrienes. PMID:16313356

  15. Longitudinal Effects of Ketamine on Dendritic Architecture In Vivo in the Mouse Medial Frontal Cortex123

    PubMed Central

    Phoumthipphavong, Victoria; Barthas, Florent; Hassett, Samantha

    2016-01-01

    Abstract A single subanesthetic dose of ketamine, an NMDA receptor antagonist, leads to fast-acting antidepressant effects. In rodent models, systemic ketamine is associated with higher dendritic spine density in the prefrontal cortex, reflecting structural remodeling that may underlie the behavioral changes. However, turnover of dendritic spines is a dynamic process in vivo, and the longitudinal effects of ketamine on structural plasticity remain unclear. The purpose of the current study is to use subcellular resolution optical imaging to determine the time course of dendritic alterations in vivo following systemic ketamine administration in mice. We used two-photon microscopy to visualize repeatedly the same set of dendritic branches in the mouse medial frontal cortex (MFC) before and after a single injection of ketamine or saline. Compared to controls, ketamine-injected mice had higher dendritic spine density in MFC for up to 2 weeks. This prolonged increase in spine density was driven by an elevated spine formation rate, and not by changes in the spine elimination rate. A fraction of the new spines following ketamine injection was persistent, which is indicative of functional synapses. In a few cases, we also observed retraction of distal apical tuft branches on the day immediately after ketamine administration. These results indicate that following systemic ketamine administration, certain dendritic inputs in MFC are removed immediately, while others are added gradually. These dynamic structural modifications are consistent with a model of ketamine action in which the net effect is a rebalancing of synaptic inputs received by frontal cortical neurons. PMID:27066532

  16. Sleep contributes to dendritic spine formation and elimination in the developing mouse somatosensory cortex.

    PubMed

    Yang, Guang; Gan, Wen-Biao

    2012-11-01

    Sleep is maximal during early postnatal life when rapid and extensive synapse remodeling occurs. It remains unknown whether and how sleep affects synapse development and plasticity. Using transcranial two-photon microscopy, we examined the formation and elimination of fluorescently labeled dendritic spines and filopodia of Layer 5 pyramidal neurons in the barrel cortex of 3-week-old mice during wakefulness and sleep. We observed high turnover of dendritic protrusions over 2 h in both wake and sleep states. The formation rate of dendritic spines or filopodia over 2 h was comparable between the two states. The elimination rate of dendritic spines or filopodia was lower during 2-h wakefulness than during 2-h sleep. Similar results were observed on dendritic protrusion dynamics over 12-h light/dark cycle when mice spent more time asleep or awake. The substantial remodeling of dendritic protrusions during the sleep state supports the notion that sleep plays an important role in the development and plasticity of synaptic connections in the mouse cortex.

  17. Longitudinal Effects of Ketamine on Dendritic Architecture In Vivo in the Mouse Medial Frontal Cortex.

    PubMed

    Phoumthipphavong, Victoria; Barthas, Florent; Hassett, Samantha; Kwan, Alex C

    2016-01-01

    A single subanesthetic dose of ketamine, an NMDA receptor antagonist, leads to fast-acting antidepressant effects. In rodent models, systemic ketamine is associated with higher dendritic spine density in the prefrontal cortex, reflecting structural remodeling that may underlie the behavioral changes. However, turnover of dendritic spines is a dynamic process in vivo, and the longitudinal effects of ketamine on structural plasticity remain unclear. The purpose of the current study is to use subcellular resolution optical imaging to determine the time course of dendritic alterations in vivo following systemic ketamine administration in mice. We used two-photon microscopy to visualize repeatedly the same set of dendritic branches in the mouse medial frontal cortex (MFC) before and after a single injection of ketamine or saline. Compared to controls, ketamine-injected mice had higher dendritic spine density in MFC for up to 2 weeks. This prolonged increase in spine density was driven by an elevated spine formation rate, and not by changes in the spine elimination rate. A fraction of the new spines following ketamine injection was persistent, which is indicative of functional synapses. In a few cases, we also observed retraction of distal apical tuft branches on the day immediately after ketamine administration. These results indicate that following systemic ketamine administration, certain dendritic inputs in MFC are removed immediately, while others are added gradually. These dynamic structural modifications are consistent with a model of ketamine action in which the net effect is a rebalancing of synaptic inputs received by frontal cortical neurons.

  18. 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.

  19. Cell-surface marker analysis of rat thymic dendritic cells.

    PubMed Central

    Bañuls, M P; Alvarez, A; Ferrero, I; Zapata, A; Ardavin, C

    1993-01-01

    Rat thymic dendritic cells have been isolated by collagenase digestion, separation of the low-density cell fraction by centrifugation on metrizamide, and differential adherence. The resulting dendritic cell preparation had a purity of > 90%, and has been analysed by flow cytometry (FCM) using a large panel of monoclonal antibodies (mAb). Dendritic cells expressed major histocompatibility (MHC) class I and class II molecules, the leucocyte common antigen CD45, the rat leucocyte antigen OX44, the rat macrophage marker ED1, and the adhesion molecules Mac-1, LFA-1 and ICAM-1. They were negative for the T- and B-cell-specific forms of CD45, CD45R and B220, and the B-cell marker OX12. Concerning T-cell marker expression, they were negative for T-cell receptor (TcR) and OX40, but they expressed CD2, CD4 and CD8, and interestingly, 50% of DC were CD5+, 50% expressed the alpha-chain of interleukin-2 receptor (IL-2R), and 80% were positive for the T-cell activation antigen recognized by the mAb OX48. Moreover, 60% of DC expressed high levels of Thy-1, whereas 40% displayed intermediate levels of this T-cell marker. PMID:8102122

  20. Dendritic cell-based immunotherapy in mesothelioma.

    PubMed

    Cornelissen, Robin; Lievense, Lysanne A; Heuvers, Marlies E; Maat, Alexander P; Hendriks, Rudi W; Hoogsteden, Henk C; Hegmans, Joost P; Aerts, Joachim G

    2012-10-01

    Mesothelioma is a rare thoracic malignancy with a dismal prognosis. Current treatment options are scarce and clinical outcomes are rather disappointing. Due to the immunogenic nature of mesothelioma, several studies have investigated immunotherapeutic strategies to improve the prognosis of patients with mesothelioma. In the last decade, progress in knowledge of the modulation of the immune system to attack the tumor has been remarkable, but the optimal strategy for immunotherapy has yet to be unraveled. Because of their potent antigen-presenting capacity, dendritic cells are acknowledged as a promising agent in immunotherapeutic approaches in a number of malignancies. This review gives an update and provides a future perspective in which immunotherapy may improve the outcome of mesothelioma therapy.

  1. Role of Dendritic Cells in Immune Dysfunction

    NASA Technical Reports Server (NTRS)

    Savary, Cherylyn A.

    1998-01-01

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

  2. Ca2+ imaging of mouse neocortical interneurone dendrites: Contribution of Ca2+-permeable AMPA and NMDA receptors to subthreshold Ca2+dynamics

    PubMed Central

    Goldberg, Jesse H; Yuste, Rafael; Tamas, Gabor

    2003-01-01

    In this second study, we have combined two-photon calcium imaging with whole-cell recording and anatomic reconstructions to directly characterize synaptically evoked calcium signals in three types of mouse V1 supragranular interneurones: parvalbumin-positive fast spikers (FS), calretinin-positive irregular spikers (IS), and adapting cells (AD). We observed that subthreshold synaptic activation evoked calcium signals locally restricted to individual dendritic compartments. These signals were mediated by NMDA receptors (NMDARs) in AD and IS cells, whereas in FS cells, calcium-permeable AMPA receptors (CP-AMPARs) provided an additional and kinetically distinct influx. Furthermore, even a single, subthreshold synaptic activation evoked a larger dendritic calcium influx than backpropagating action potentials. Our results demonstrate that NMDARs dominate subthreshold calcium dynamics in interneurones and reveal the functional contribution of CP-AMPARs to a specific subclass of cortical interneurone. These data highlight different strategies in dendritic signal processing by distinct classes of interneurones. PMID:12844507

  3. Targeting Skin Dendritic Cells to Improve Intradermal Vaccination

    PubMed Central

    Romani, N.; Flacher, V.; Tripp, C. H.; Sparber, F.; Ebner, S.; Stoitzner, P.

    2014-01-01

    Vaccinations in medicine are typically administered into the muscle beneath the skin or into the subcutaneous fat. As a consequence, the vaccine is immunologically processed by antigen-presenting cells of the skin or the muscle. Recent evidence suggests that the clinically seldom used intradermal route is effective and possibly even superior to the conventional subcutaneous or intramuscular route. Several types of professional antigen-presenting cells inhabit the healthy skin. Epidermal Langerhans cells (CD207/langerin+), dermal langerinneg, and dermal langerin+ dendritic cells (DC) have been described, the latter subset so far only in mouse skin. In human skin langerinneg dermal DC can be further classified based on their reciprocal expression of CD1a and CD14. The relative contributions of these subsets to the generation of immunity or tolerance are still unclear. Yet, specializations of these different populations have become apparent. Langerhans cells in human skin appear to be specialized for induction of cytotoxic T lymphocytes; human CD14+ dermal DC can promote antibody production by B cells. It is currently attempted to rationally devise and improve vaccines by harnessing such specific properties of skin DC. This could be achieved by specifically targeting functionally diverse skin DC subsets. We discuss here advances in our knowledge on the immunological properties of skin DC and strategies to significantly improve the outcome of vaccinations by applying this knowledge. PMID:21253784

  4. Minocycline promotes the generation of dendritic cells with regulatory properties

    PubMed Central

    Im, Sun-A; Kim, Ji-Wan; Lee, Jae-Hee; Park, Young-Jun; Song, Sukgil; Lee, Chong-Kil

    2016-01-01

    Minocycline, which has long been used as a broad-spectrum antibiotic, also exhibits non-antibiotic properties such as inhibition of inflammation and angiogenesis. In this study, we show that minocycline significantly enhances the generation of dendritic cells (DCs) from mouse bone marrow (BM) cells when used together with GM-CSF and IL-4. DCs generated from BM cells in the presence of minocycline (Mino-DCs) demonstrate the characteristics of regulatory DCs. Compared with control DCs, Mino-DCs are resistant to subsequent maturation stimuli, impaired in MHC class II-restricted exogenous Ag presentation, and show decreased cytokine secretion. Mino-DCs also show decreased ability to prime allogeneic-specific T cells, while increasing the expansion of CD4+CD25+Foxp3+ T regulatory cells both in vitro and in vivo. In addition, pretreatment with MOG35-55 peptide-pulsed Mino-DCs ameliorates clinical signs of experimental autoimmune encephalitis induced by MOG peptide injection. Our study identifies minocycline as a new pharmacological agent that could be potentially used to increase the production of regulatory DCs for cell therapy to treat autoimmune disorders, allergy, and transplant rejection. PMID:27463004

  5. Macrophages and Dendritic Cells: Partners in Atherogenesis.

    PubMed

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

    2016-02-19

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

  6. DENDRITIC CELLS: ARE THEY CLINICALLY RELEVANT?

    PubMed Central

    Palucka, Karolina; Ueno, Hideki; Roberts, Lee; Fay, Joseph; Banchereau, Jacques

    2010-01-01

    Cancer vaccines have undergone a renaissance due to recent clinical trials showing promising immunological data and some clinical benefit to patients. Current trials exploiting dendritic cells (DCs) as vaccines have shown durable tumor regressions in a fraction of patients. Clinical efficacy of current vaccines is hampered by myeloid-derived suppressor cells, inflammatory type 2 T cells and regulatory T cells (Tregs), all of which prevent the generation of effector cells. To improve the clinical efficacy of DC vaccines, we need to design novel and improved strategies that can boost adaptive immunity to cancer, help overcome Tregs and allow the breakdown of the immunosuppressive tumor microenvironment. This can be achieved by exploiting the fast increasing knowledge about the DC system, including the existence of distinct DC subsets. Critical to the design of better vaccines is the concept of distinct DC subsets and distinct DC activation pathways, all contributing to the generation of unique adaptive immune responses. Such novel DC vaccines will be used as monotherapy in patients with resected disease and in combination with antibodies and/or drugs targeting suppressor pathways and modulation of the tumor environment in patients with metastatic disease. PMID:20693842

  7. Engineering Dendritic Cells to Enhance Cancer Immunotherapy

    PubMed Central

    Boudreau, Jeanette E; Bonehill, Aude; Thielemans, Kris; Wan, Yonghong

    2011-01-01

    Cancer immunotherapy aims to establish immune-mediated control of tumor growth by priming T-cell responses to target tumor-associated antigens. Three signals are required for T-cell activation: (i) presentation of cognate antigen in self MHC molecules; (ii) costimulation by membrane-bound receptor-ligand pairs; and (iii) soluble factors to direct polarization of the ensuing immune response. The ability of dendritic cells (DCs) to provide all three signals required for T-cell activation makes them an ideal cancer vaccine platform. Several strategies have been developed to enhance and control antigen presentation, costimulation, and cytokine production. In this review, we discuss progress toward developing DC-based cancer vaccines by genetic modification using RNA, DNA, and recombinant viruses. Furthermore, the ability of DC-based vaccines to activate natural killer (NK) and B-cells, and the impact of gene modification strategies on these populations is described. Clinical trials using gene-modified DCs have shown modest results, therefore, further considerations for DC manipulation to enhance their clinical efficacy are also discussed. PMID:21468005

  8. MicroRNA-100-5p indirectly modulates the expression of Il6, Ptgs1/2 and Tlr4 mRNA in the mouse follicular dendritic cell-like cell line, FL-Y

    PubMed Central

    Aungier, Susan R; Ohmori, Hitoshi; Clinton, Michael; Mabbott, Neil A

    2015-01-01

    Follicular dendritic cells (FDC) are important stromal cells within the B-cell follicles and germinal centres (GC) of secondary lymphoid tissues. FDC trap and retain native antigens on their surfaces in the form of immune complexes that they display to B cells, in order to select those cells with the highest antigen affinity. MicroRNAs are short, non-coding RNAs that are approximately 18–25 nucleotides in length that regulate gene expression at the post-transcriptional level by repressing the translation of target genes. In the current study, in vivo and in vitro systems were used to identify microRNAs that were potentially expressed by FDC. Constitutive lymphotoxin-β receptor (LTβR) stimulation is required to maintain FDC in their differentiated state. We show that the rapid de-differentiation of spleen FDC that accompanied LTβR-blockade, coincided with a significant decrease in the expression of mmu-miR-100-5p, mmu-miR-138-5p and mmu-miR-2137. These microRNAs were shown to be expressed in the FDC-like cell line, FL-YB, and specific inhibition of mmu-miR-100-5p significantly enhanced expression of Il6, Ptgs1/2 and Tlr4 mRNA in this cell line. The expression of Il6, Ptgs1/2 and Tlr4 by FDC play important roles in regulating GC size and promoting high-affinity antibody responses, so it is plausible that mmu-miR-100-5p may help to regulate the expression of these genes during GC reactions. PMID:24944008

  9. Active Dendritic Properties and Local Inhibitory Input Enable Selectivity for Object Motion in Mouse Superior Colliculus Neurons.

    PubMed

    Gale, Samuel D; Murphy, Gabe J

    2016-08-31

    Neurons respond to specific features of sensory stimuli. In the visual system, for example, some neurons respond to motion of small but not large objects, whereas other neurons prefer motion of the entire visual field. Separate neurons respond equally to local and global motion but selectively to additional features of visual stimuli. How and where does response selectivity emerge? Here, we show that wide-field (WF) cells in retino-recipient layers of the mouse superior colliculus (SC) respond selectively to small moving objects. Moreover, we identify two mechanisms that contribute to this selectivity. First, we show that input restricted to a small portion of the broad dendritic arbor of WF cells is sufficient to trigger dendritic spikes that reliably propagate to the soma/axon. In vivo whole-cell recordings reveal that nearly every action potential evoked by visual stimuli has characteristics of spikes initiated in dendrites. Second, inhibitory input from a different class of SC neuron, horizontal cells, constrains the range of stimuli to which WF cells respond. Horizontal cells respond preferentially to the sudden appearance or rapid movement of large stimuli. Optogenetic reduction of their activity reduces movement selectivity and broadens size tuning in WF cells by increasing the relative strength of responses to stimuli that appear suddenly or cover a large region of space. Therefore, strongly propagating dendritic spikes enable small stimuli to drive spike output in WF cells and local inhibition helps restrict responses to stimuli that are both small and moving. How do neurons respond selectively to some sensory stimuli but not others? In the visual system, a particularly relevant stimulus feature is object motion, which often reveals other animals. Here, we show how specific cells in the superior colliculus, one synapse downstream of the retina, respond selectively to object motion. These wide-field (WF) cells respond strongly to small objects that move

  10. Role of dendritic cells in cardiovascular diseases

    PubMed Central

    Zhang, Yi; Zhang, Cuihua

    2010-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells that bridge innate and adaptive immune responses. Recent work has elucidated the DC life cycle, including several important stages such as maturation, migration and homeostasis, as well as DC classification and subsets/locations, which provided etiological insights on the role of DCs in disease processes. DCs have a close relationship to endothelial cells and they interact with each other to maintain immunity. DCs are deposited in the atherosclerotic plaque and contribute to the pathogenesis of atherosclerosis. In addition, the necrotic cardiac cells induced by ischemia activate DCs by Toll-like receptors, which initiate innate and adaptive immune responses to renal, hepatic and cardiac ischemia reperfusion injury (IRI). Furthermore, DCs are involved in the acute/chronic rejection of solid organ transplantation and mediate transplant tolerance as well. Advancing our knowledge of the biology of DCs will aid development of new approaches to treat many cardiovascular diseases, including atherosclerosis, cardiac IRI and transplantation. PMID:21179302

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

    PubMed

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

    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.

  12. Revving Up Dendritic Cells while Braking PD-L1 to Jump-Start the Cancer-Immunity Cycle Motor.

    PubMed

    Coffelt, Seth B; de Visser, Karin E

    2016-04-19

    Although it is successful for some, most melanoma patients are refractory to T cell checkpoint inhibition. In this issue of Immunity, Merad and colleagues (2016) describe a dendritic-cell-based strategy to heighten the efficacy of therapeutic anti-PD-L1 and BRAF inhibitors in mouse melanoma models.

  13. Metabolism Is Central to Tolerogenic Dendritic Cell Function

    PubMed Central

    Sim, Wen Jing; Ahl, Patricia Jennifer; Connolly, John Edward

    2016-01-01

    Immunological tolerance is a fundamental tenant of immune homeostasis and overall health. Self-tolerance is a critical component of the immune system that allows for the recognition of self, resulting in hyporeactivity instead of immunogenicity. Dendritic cells are central to the establishment of dominant immune tolerance through the secretion of immunosuppressive cytokines and regulatory polarization of T cells. Cellular metabolism holds the key to determining DC immunogenic or tolerogenic cell fate. Recent studies have demonstrated that dendritic cell maturation leads to a shift toward a glycolytic metabolic state and preferred use of glucose as a carbon source. In contrast, tolerogenic dendritic cells favor oxidative phosphorylation and fatty acid oxidation. This dichotomous metabolic reprogramming of dendritic cells drives differential cellular function and plays a role in pathologies, such as autoimmune disease. Pharmacological alterations in metabolism have promising therapeutic potential. PMID:26980944

  14. Transcriptional profiling of dendritic cells matured in different osmolarities.

    PubMed

    Chessa, Federica; Hielscher, Thomas; Mathow, Daniel; Gröne, Hermann-Josef; Popovic, Zoran V

    2016-03-01

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

  15. Follicular dendritic cell sarcoma of the abdomen: the imaging findings.

    PubMed

    Kang, Tae Wook; Lee, Soon Jin; Song, Hye Jong

    2010-01-01

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

  16. Impulse encoding across the dendritic morphologies of retinal ganglion cells.

    PubMed

    Sheasby, B W; Fohlmeister, J F

    1999-04-01

    Nerve impulse entrainment and other excitation and passive phenomena are analyzed for a morphologically diverse and exhaustive data set (n = 57) of realistic (3-dimensional computer traced) soma-dendritic tree structures of ganglion cells in the tiger salamander (Ambystoma tigrinum) retina. The neurons, including axon and an anatomically specialized thin axonal segment that is observed in every ganglion cell, were supplied with five voltage- or ligand-gated ion channels (plus leakage), which were distributed in accordance with those found in a recent study that employed an equivalent dendritic cylinder. A wide variety of impulse-entrainment responses was observed, including regular low-frequency firing, impulse doublets, and more complex patterns involving impulse propagation failures (or aborted spikes) within the encoder region, all of which have been observed experimentally. The impulse-frequency response curves of the cells fell into three groups called FAST, MEDIUM, and SLOW in approximate proportion as seen experimentally. In addition to these, a new group was found among the traced cells that exhibited an impulse-frequency response twice that of the FAST category. The total amount of soma-dendritic surface area exhibited by a given cell is decisive in determining its electrophysiological classification. On the other hand, we found only a weak correlation between the electrophysiological group and the morphological classification of a given cell, which is based on the complexity of dendritic branching and the physical reach or "receptive field" area of the cell. Dendritic morphology determines discharge patterns to dendritic (synaptic) stimulation. Orthodromic impulses can be initiated on the axon hillock, the thin axonal segment, the soma, or even the proximal axon beyond the thin segment, depending on stimulus magnitude, soma-dendritic membrane area, channel distribution, and state within the repetitive impulse cycle. Although a sufficiently high dendritic

  17. Dendritic Cell Interactions with Lymphatic Endothelium

    PubMed Central

    Russo, Erica; Nitschké, Maximilian

    2013-01-01

    Abstract Afferent lymphatic vessels fulfill essential immune functions by transporting leukocytes and lymph-borne antigen to draining lymph nodes (dLNs). An important cell type migrating through lymphatic vessels are dendritic cells (DCs). DCs reside in peripheral tissues like the skin, where they take up antigen and transport it via the lymphatic vascular network to dLNs for subsequent presentation to T cells. As such, DCs play a key role in the induction of adaptive immune responses during infection and vaccination, but also for the maintenance of tolerance. Although the migratory pattern of DCs has been known for long time, interactions between DCs and lymphatic vessels are only now starting to be unraveled at the cellular level. In particular, new tools for visualizing lymphatic vessels in combination with time-lapse microscopy have recently generated valuable insights into the process of DC migration to dLNs. In this review we summarize and discuss current approaches for visualizing DCs and lymphatic vessels in tissues for imaging applications. Furthermore, we review the current state of knowledge about DC migration towards, into and within lymphatic vessels, particularly focusing on the cellular interactions that take place between DCs and the lymphatic endothelium. PMID:24044757

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

    PubMed

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

    1999-08-01

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

  19. Neuroimmune interactions: dendritic cell modulation by the sympathetic nervous system.

    PubMed

    Takenaka, Maisa C; Guereschi, Marcia G; Basso, Alexandre S

    2017-02-01

    Dendritic cells are of paramount importance bridging innate and adaptive immune responses. Depending on the context, after sensing environmental antigens, commensal microorganisms, pathogenic agents, or antigens from the diet, dendritic cells may drive either different effector adaptive immune responses or tolerance, avoiding tissue damage. Although the plasticity of the immune response and the capacity to regulate itself are considered essential to orchestrate appropriate physiological responses, it is known that the nervous system plays a relevant role controlling immune cell function. Dendritic cells present in the skin, the intestine, and lymphoid organs, besides expressing adrenergic receptors, can be reached by neurotransmitters released by sympathetic fibers innervating these tissues. These review focus on how neurotransmitters from the sympathetic nervous system can modulate dendritic cell function and how this may impact the immune response and immune-mediated disorders.

  20. Use and abuse of dendritic cells by Toxoplasma gondii

    PubMed Central

    Sanecka, Anna; Frickel, Eva-Maria

    2012-01-01

    The ubiquitous apicomplexan parasite Toxoplasma gondii stimulates its host’s immune response to achieve quiescent chronic infection. Central to this goal are host dendritic cells. The parasite exploits dendritic cells to disseminate through the body, produce pro-inflammatory cytokines, present its antigens to the immune system and yet at the same time subvert their signaling pathways in order to evade detection. This carefully struck balance by Toxoplasma makes it the most successful parasite on this planet. Recent progress has highlighted specific parasite and host molecules that mediate some of these processes particularly in dendritic cells and in other cells of the innate immune system. Critically, there are several important factors that need to be taken into consideration when concluding how the dendritic cells and the immune system deal with a Toxoplasma infection, including the route of administration, parasite strain and host genotype. PMID:23221473

  1. Involvement of suppressive B-lymphocytes in the mechanism of tolerogenic dendritic cell reversal of type 1 diabetes in NOD mice.

    PubMed

    Di Caro, Valentina; Phillips, Brett; Engman, Carl; Harnaha, Jo; Trucco, Massimo; Giannoukakis, Nick

    2014-01-01

    The objective of the study was to identify immune cell populations, in addition to Foxp3+ T-regulatory cells, that participate in the mechanisms of action of tolerogenic dendritic cells shown to prevent and reverse type 1 diabetes in the Non-Obese Diabetic (NOD) mouse strain. Co-culture experiments using tolerogenic dendritic cells and B-cells from NOD as well as transgenic interleukin-10 promoter-reporter mice along with transfer of tolerogenic dendritic cells and CD19+ B-cells into NOD and transgenic mice, showed that these dendritic cells increased the frequency and numbers of interleukin-10-expressing B-cells in vitro and in vivo. The expansion of these cells was a consequence of both the proliferation of pre-existing interleukin-10-expressing B-lymphocytes and the conversion of CD19+ B-lymphcytes into interleukin-10-expressing cells. The tolerogenic dendritic cells did not affect the suppressive activity of these B-cells. Furthermore, we discovered that the suppressive murine B-lymphocytes expressed receptors for retinoic acid which is produced by the tolerogenic dendritic cells. These data assist in identifying the nature of the B-cell population increased in response to the tolerogenic dendritic cells in a clinical trial and also validate very recent findings demonstrating a mechanistic link between human tolerogenic dendritic cells and immunosuppressive regulatory B-cells.

  2. CXCR4 engagement promotes dendritic cell survival and maturation

    SciTech Connect

    Kabashima, Kenji Sugita, Kazunari; Shiraishi, Noriko; Tamamura, Hirokazu; Fujii, Nobutaka; Tokura, Yoshiki

    2007-10-05

    It has been reported that human monocyte derived-dendritic cells (DCs) express CXCR4, responsible for chemotaxis to CXCL12. However, it remains unknown whether CXCR4 is involved in other functions of DCs. Initially, we found that CXCR4 was expressed on bone marrow-derived DCs (BMDCs). The addition of specific CXCR4 antagonist, 4-F-Benzoyl-TN14003, to the culture of mouse BMDCs decreased their number, especially the mature subset of them. The similar effect was found on the number of Langerhans cells (LCs) but not keratinocytes among epidermal cell suspensions. Since LCs are incapable of proliferating in vitro, these results indicate that CXCR4 engagement is important for not only maturation but also survival of DCs. Consistently, the dinitrobenzene sulfonic acid-induced, antigen-specific in vitro proliferation of previously sensitized lymph node cells was enhanced by CXCL12, and suppressed by CXCR4 antagonist. These findings suggest that CXCL12-CXCR4 engagement enhances DC maturation and survival to initiate acquired immune response.

  3. Systemic IL-12 Administration Alters Hepatic Dendritic Cell Stimulation Capabilities

    PubMed Central

    Chan, Tim; Back, Timothy C.; Subleski, Jeffrey J.; Weiss, Jonathan M.; Ortaldo, John R.; Wiltrout, Robert H.

    2012-01-01

    The liver is an immunologically unique organ containing tolerogenic dendritic cells (DC) that maintain an immunosuppressive microenvironment. Although systemic IL-12 administration can improve responses to tumors, the effects of IL-12-based treatments on DC, in particular hepatic DC, remain incompletely understood. In this study, we demonstrate systemic IL-12 administration induces a 2–3 fold increase in conventional, but not plasmacytoid, DC subsets in the liver. Following IL-12 administration, hepatic DC became more phenotypically and functionally mature, resembling the function of splenic DC, but differed as compared to their splenic counterparts in the production of IL-12 following co-stimulation with toll-like receptor (TLR) agonists. Hepatic DCs from IL-12 treated mice acquired enhanced T cell proliferative capabilities similar to levels observed using splenic DCs. Furthermore, IL-12 administration preferentially increased hepatic T cell activation and IFNγ expression in the RENCA mouse model of renal cell carcinoma. Collectively, the data shows systemic IL-12 administration enables hepatic DCs to overcome at least some aspects of the inherently suppressive milieu of the hepatic environment that could have important implications for the design of IL-12-based immunotherapeutic strategies targeting hepatic malignancies and infections. PMID:22428016

  4. Dendritic cells--why can they help and hurt us.

    PubMed

    Schäkel, Knut

    2009-03-01

    Dendritic cells (DCs) show a Janus-like functional behavior. They help us by their orchestration of numerous immune responses to defend our body against invading pathogenic micro-organisms and also induce regulatory T cells to inhibit immune reactions against autoantigens as well as diverse harmless environmental antigens. However, DCs can also be of harm to us when misguided by their microenvironment as in allergic and autoimmune diseases or when DCs are targeted and exploited by microbes and cancer cells to evade the immune defense. This huge and diverse functional repertoire of DCs requires complex decision-making processes and the integration of multiple stimulatory and inhibitory signals. Although a given DC type has an extensive functionally plasticity, DCs are heterogeneous and individual DC subtypes are differentially distributed in tissues, express distinct sets of pattern recognition receptors and differ in their capacity to program naive T cells. With the help of transgenic mouse models and selective ablation of individual DC subtypes, we are just at the beginning of understanding the DC system in its complexity. Obtaining a more detailed knowledge of the DC system in mice and men holds strong promise for the successful induction of immunity and tolerance in therapeutic trials. This review presents the recent advances in the understanding of DC biology and discusses why and how DC can help and hurt us.

  5. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas.

    PubMed

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-08-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas.

  6. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas

    PubMed Central

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-01-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas. PMID:25081193

  7. Nanoscopy of filamentous actin in cortical dendrites of a living mouse.

    PubMed

    Willig, Katrin I; Steffens, Heinz; Gregor, Carola; Herholt, Alexander; Rossner, Moritz J; Hell, Stefan W

    2014-01-07

    We demonstrate superresolution fluorescence microscopy (nanoscopy) of protein distributions in a mammalian brain in vivo. Stimulated emission depletion microscopy reveals the morphology of the filamentous actin in dendritic spines down to 40 μm in the molecular layer of the visual cortex of an anesthetized mouse. Consecutive recordings at 43-70 nm resolution reveal dynamical changes in spine morphology. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Dendritic cell interactions with Histoplasma and Paracoccidioides

    PubMed Central

    Thind, Sharanjeet K; Taborda, Carlos P; Nosanchuk, Joshua D

    2015-01-01

    Fungi are among the most common microbes encountered by humans. More than 100, 000 fungal species have been described in the environment to date, however only a few species cause disease in humans. Fungal infections are of particular importance to immunocompromised hosts in whom disease is often more severe, especially in those with impaired cell-mediated immunity such as individuals with HIV infection, hematologic malignancies, or those receiving TNF-α inhibitors. Nevertheless, environmental disturbances through natural processes or as a consequence of deforestation or construction can expose immunologically competent people to a large number of fungal spores resulting in asymptomatic acquisition to life-threatening disease. In recent decades, the significance of the innate immune system and more importantly the role of dendritic cells (DC) have been found to play a fundamental role in the resolution of fungal infections, such as in dimorphic fungi like Histoplasma and Paracoccidioides. In this review article the general role of DCs will be illustrated as the bridge between the innate and adaptive immune systems, as well as their specific interactions with these 2 dimorphic fungi. PMID:25933034

  9. 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

  10. Mycobacterium avium subspecies impair dendritic cell maturation.

    PubMed

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

    2013-10-01

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

  11. Dendritic cell interactions with Histoplasma and Paracoccidioides.

    PubMed

    Thind, Sharanjeet K; Taborda, Carlos P; Nosanchuk, Joshua D

    2015-01-01

    Fungi are among the most common microbes encountered by humans. More than 100, 000 fungal species have been described in the environment to date, however only a few species cause disease in humans. Fungal infections are of particular importance to immunocompromised hosts in whom disease is often more severe, especially in those with impaired cell-mediated immunity such as individuals with HIV infection, hematologic malignancies, or those receiving TNF-α inhibitors. Nevertheless, environmental disturbances through natural processes or as a consequence of deforestation or construction can expose immunologically competent people to a large number of fungal spores resulting in asymptomatic acquisition to life-threatening disease. In recent decades, the significance of the innate immune system and more importantly the role of dendritic cells (DC) have been found to play a fundamental role in the resolution of fungal infections, such as in dimorphic fungi like Histoplasma and Paracoccidioides. In this review article the general role of DCs will be illustrated as the bridge between the innate and adaptive immune systems, as well as their specific interactions with these 2 dimorphic fungi.

  12. Kidney dendritic cells in acute and chronic renal disease.

    PubMed

    Hochheiser, Katharina; Tittel, André; Kurts, Christian

    2011-06-01

    Dendritic cells are not only the master regulators of adaptive immunity, but also participate profoundly in innate immune responses. Much has been learned about their basic immunological functions and their roles in various diseases. Comparatively little is still known about their role in renal disease, despite their obvious potential to affect immune responses in the kidney, and immune responses that are directed against renal components. Kidney dendritic cells form an abundant network in the renal tubulointerstitium and constantly survey the environment for signs of injury or infection, in order to alert the immune system to the need to initiate defensive action. Recent studies have identified a role for dendritic cells in several murine models of acute renal injury and chronic nephritis. Here we summarize the current knowledge on the role of kidney dendritic cells that has been obtained from the study of murine models of renal disease. © 2010 The Authors. Journal compilation © 2010 Blackwell Publishing Ltd.

  13. [Dendritic cells and gliomas: a hope in immunotherapy?].

    PubMed

    Jouanneau, E; Poujol, D; Caux, C; Belin, M-F; Blay, J-Y; Puisieux, I

    2006-12-01

    Immunotherapy has been explored for several decades to try to improve the prognosis of gliomas, but until recently no therapeutic benefit has been achieved. The discovery of dendritic cells, the most potent professional antigen presenting cells to initiate specific immune response, and the possibility of producing them ex vivo gave rise to new protocols of active immunotherapy. In oncology, promising experimental and clinical therapeutic results were obtained using these dendritic cells loaded with tumor antigen. Patients bearing gliomas have deficit antigen presentation making this approach rational. In several experimental glioma models, independent research teams have showed specific antitumor responses using these dendritic cells. Phase I/II clinical trials have demonstrated the feasibility and the tolerance of this immunotherapeutic approach. In neuro-oncology, the efficiency of such an approach remains to be established, similarly in oncology where positive phase III studies are missing. Nevertheless, dendritic cells comprise a complex network which is only partially understood and capable of generating either immunotolerance or immune response. Numerous parameters remain to be explored before any definitive conclusion about their utility as an anticancer weapon can be drawn. It seems however logical that immunotherapy with dendritic cells could prevent or delay tumor recurrence in patients with minor active disease. A review on glioma and dendritic cells is presented.

  14. Hoxb8 conditionally immortalised macrophage lines model inflammatory monocytic cells with important similarity to dendritic cells.

    PubMed

    Rosas, Marcela; Osorio, Fabiola; Robinson, Matthew J; Davies, Luke C; Dierkes, Nicola; Jones, Simon A; Reis e Sousa, Caetano; Taylor, Philip R

    2011-02-01

    We have examined the potential to generate bona fide macrophages (MØ) from conditionally immortalised murine bone marrow precursors. MØ can be derived from Hoxb8 conditionally immortalised macrophage precursor cell lines (MØP) using either M-CSF or GM-CSF. When differentiated in GM-CSF (GM-MØP) the resultant cells resemble GM-CSF bone marrow-derived dendritic cells (BMDC) in morphological phenotype, antigen phenotype and functional responses to microbial stimuli. In spite of this high similarity between the two cell types and the ability of GM-MØP to effectively present antigen to a T-cell hybridoma, these cells are comparatively poor at priming the expansion of IFN-γ responses from naïve CD4(+) T cells. The generation of MØP from transgenic or genetically aberrant mice provides an excellent opportunity to study the inflammatory role of GM-MØP, and reduces the need for mouse colonies in many studies. Hence differentiation of conditionally immortalised MØPs in GM-CSF represents a unique in vitro model of inflammatory monocyte-like cells, with important differences from bone marrow-derived dendritic cells, which will facilitate functional studies relating to the many 'sub-phenotypes' of inflammatory monocytes.

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

    PubMed Central

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

    2014-01-01

    Human monocyte-derived dendritic cell (MoDC) have been used in the clinic with moderately encouraging results. Mouse XCR1+ DC excel at cross-presentation, can be targeted in vivo to induce protective immunity, and share characteristics with XCR1+ human DC. Assessment of the immunoactivation potential of XCR1+ human DC is hindered by their paucity in vivo and by their lack of a well-defined in vitro counterpart. We report in this study a protocol generating both XCR1+ and XCR1− human DC in CD34+ progenitor cultures (CD34-DC). Gene expression profiling, phenotypic characterization, and functional studies demonstrated that XCR1− CD34-DC are similar to canonical MoDC, whereas XCR1+ CD34-DC resemble XCR1+ blood DC (bDC). XCR1+ DC were strongly activated by polyinosinic-polycytidylic acid but not LPS, and conversely for MoDC. XCR1+ DC and MoDC expressed strikingly different patterns of molecules involved in inflammation and in cross-talk with NK or T cells. XCR1+ CD34-DC but not MoDC efficiently cross-presented a cell-associated Ag upon stimulation by polyinosinic-polycytidylic acid or R848, likewise to what was reported for XCR1+ bDC. Hence, it is feasible to generate high numbers of bona fide XCR1+ human DC in vitro as a model to decipher the functions of XCR1+ bDC and as a potential source of XCR1+ DC for clinical use. PMID:25009205

  16. 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.

  17. Aire-Overexpressing Dendritic Cells Induce Peripheral CD4+ T Cell Tolerance

    PubMed Central

    Li, Dongbei; Li, Haijun; Fu, Haiying; Niu, Kunwei; Guo, Yantong; Guo, Chuan; Sun, Jitong; Li, Yi; Yang, Wei

    2015-01-01

    Autoimmune regulator (Aire) can promote the ectopic expression of peripheral tissue-restricted antigens (TRAs) in thymic medullary epithelial cells (mTECs), which leads to the deletion of autoreactive T cells and consequently prevents autoimmune diseases. However, the functions of Aire in the periphery, such as in dendritic cells (DCs), remain unclear. This study’s aim was to investigate the effect of Aire-overexpressing DCs (Aire cells) on the functions of CD4+ T cells and the treatment of type 1 diabetes (T1D). We demonstrated that Aire cells upregulated the mRNA levels of the tolerance-related molecules CD73, Lag3, and FR4 and the apoptosis of CD4+ T cells in STZ-T1D mouse-derived splenocytes. Furthermore, following insulin stimulation, Aire cells decreased the number of CD4+ IFN-γ+ T cells in both STZ-T1D and WT mouse-derived splenocytes and reduced the expression levels of TCR signaling molecules (Ca2+ and p-ERK) in CD4+ T cells. We observed that Aire cells-induced CD4+ T cells could delay the development of T1D. In summary, Aire-expressing DCs inhibited TCR signaling pathways and decreased the quantity of CD4+IFN-γ+ autoreactive T cells. These data suggest a mechanism for Aire in the maintenance of peripheral immune tolerance and provide a potential method to control autoimmunity by targeting Aire. PMID:26729097

  18. Dendritic Cells and Macrophages: Sentinels in the Kidney

    PubMed Central

    Weisheit, Christina K.; Engel, Daniel R.

    2015-01-01

    The mononuclear phagocytes (dendritic cells and macrophages) are closely related immune cells with central roles in anti-infectious defense and maintenance of organ integrity. The canonical function of dendritic cells is the activation of T cells, whereas macrophages remove apoptotic cells and microbes by phagocytosis. In the kidney, these cell types form an intricate system of mononuclear phagocytes that surveys against injury and infection and contributes to organ homeostasis and tissue repair but may also promote progression of CKD. This review summarizes the general functions and classification of dendritic cells and macrophages in the immune system and recapitulates why overlapping definitions and historically separate research have created controversy about their tasks. Their roles in acute kidney disease, CKD, and renal transplantation are described, and therapeutic strategy to modify these cells for therapeutic purposes is discussed. PMID:25568218

  19. The effect of dendritic cells on the retinal cell transplantation

    SciTech Connect

    Oishi, Akio; Nagai, Takayuki; Mandai, Michiko Takahashi, Masayo; Yoshimura, Nagahisa

    2007-11-16

    The potential of bone marrow cell-derived immature dendritic cells (myeloid iDCs) in modulating the efficacy of retinal cell transplantation therapy was investigated. (1) In vitro, myeloid iDCs but not BMCs enhanced the survival and proliferation of embryonic retinal cells, and the expression of various neurotrophic factors by myeloid iDCs was confirmed with RT-PCR. (2) In subretinal transplantation, neonatal retinal cells co-transplanted with myeloid iDCs showed higher survival rate compared to those transplanted without myeloid iDCs. (3) CD8 T-cells reactive against donor retinal cells were significantly increased in the mice with transplantation of retinal cells alone. These results suggested the beneficial effects of the use of myeloid iDCs in retinal cell transplantation therapy.

  20. Dendrites of rod bipolar cells sprout in normal aging retina.

    PubMed

    Liets, Lauren C; Eliasieh, Kasra; van der List, Deborah A; Chalupa, Leo M

    2006-08-08

    The aging nervous system is known to manifest a variety of degenerative and regressive events. Here we report the unexpected growth of dendrites in the retinas of normal old mice. The dendrites of many rod bipolar cells in aging mice were observed to extend well beyond their normal strata within the outer plexiform layer to innervate the outer nuclear layer where they appeared to form contacts with the spherules of rod photoreceptors. Such dendritic sprouting increased with age and was evident at all retinal eccentricities. These results provide evidence of retinal plasticity associated with normal aging.

  1. Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases

    PubMed Central

    Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

    2009-01-01

    Background Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Design and Methods Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Results Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-α) and also induced allogeneic naive CD4+ T cells to proliferate and to produce type 1 cytokines such as interferon-γ and tumor necrosis factor-α. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Conclusions Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in

  2. Depletion of cutaneous macrophages and dendritic cells promotes growth of basal cell carcinoma in mice.

    PubMed

    König, Simone; Nitzki, Frauke; Uhmann, Anja; Dittmann, Kai; Theiss-Suennemann, Jennifer; Herrmann, Markus; Reichardt, Holger M; Schwendener, Reto; Pukrop, Tobias; Schulz-Schaeffer, Walter; Hahn, Heidi

    2014-01-01

    Basal cell carcinoma (BCC) belongs to the group of non-melanoma skin tumors and is the most common tumor in the western world. BCC arises due to mutations in the tumor suppressor gene Patched1 (Ptch). Analysis of the conditional Ptch knockout mouse model for BCC reveals that macrophages and dendritic cells (DC) of the skin play an important role in BCC growth restraining processes. This is based on the observation that a clodronate-liposome mediated depletion of these cells in the tumor-bearing skin results in significant BCC enlargement. The depletion of these cells does not modulate Ki67 or K10 expression, but is accompanied by a decrease in collagen-producing cells in the tumor stroma. Together, the data suggest that cutaneous macrophages and DC in the tumor microenvironment exert an antitumor effect on BCC.

  3. Plumbagin suppresses dendritic cell functions and alleviates experimental autoimmune encephalomyelitis.

    PubMed

    Zhang, Kai; Ge, Zhenzhen; Da, Yurong; Wang, Dong; Liu, Ying; Xue, Zhenyi; Li, Yan; Li, Wen; Zhang, Lijuan; Wang, Huafeng; Zhang, Huan; Peng, Meiyu; Hao, Junwei; Yao, Zhi; Zhang, Rongxin

    2014-08-15

    Plumbagin (PL, 5-hydroxy-2-methyl-1,4-naphthoquinone) is a herbal compound derived from medicinal plants of the Droseraceae, Plumbaginaceae, Dioncophyllaceae, and Ancistrocladaceae families. Reports have shown that PL exerts immunomodulatory activity and may be a novel drug candidate for immune-related disease therapy. However, its effects on dendritic cells (DCs), the most potent antigen-presenting cells (APCs), remain unclear. In this study, we demonstrate that PL inhibits the differentiation, maturation, and function of human monocyte-derived DCs. PL can also restrict the expression of Th1- and Th17-polarizing cytokines in mDC. In addition, PL suppresses DCs both in vitro and in vivo, as demonstrated by its effects on the mouse DC line DC2.4 and mice with experimental autoimmune encephalomyelitis (EAE), respectively. Notably, PL ameliorated the clinical symptoms of EAE, including central nervous system (CNS) inflammation and demyelination. Our results demonstrate the immune suppressive and anti-inflammatory properties of PL via its effects on DCs and suggest that PL could be a potential treatment for DC-related autoimmune and inflammatory diseases.

  4. Cell cycle in mouse development.

    PubMed

    Ciemerych, Maria A; Sicinski, Peter

    2005-04-18

    Mice likely represent the most-studied mammalian organism, except for humans. Genetic engineering in embryonic stem cells has allowed derivation of mouse strains lacking particular cell cycle proteins. Analyses of these mutant mice, and cells derived from them, facilitated the studies of the functions of cell cycle apparatus at the organismal and cellular levels. In this review, we give some background about the cell cycle progression during mouse development. We next discuss some insights about in vivo functions of the cell cycle proteins, gleaned from mouse knockout experiments. Our text is meant to provide examples of the recent experiments, rather than to supply an extensive and complete list.

  5. [Glucocorticoids and their effect on dendritic cell function].

    PubMed

    Rozková, D; Horváth, R; Bartůnková, J; Spísek, R

    2005-01-01

    Dendritic cells represent the most effective antigen presenting cells and they are the only cell type capable of initiating the primary immune response. They use several sets of germ-line encoded receptors to differentiate between self and non-self and to detect the presence of danger signals. Danger signals are mainly represented by microbial pathogens but it can be also a necrotic or malignant cell. At various stages of their lifecycle dendritic cells play a key role in maintaining the peripheral tolerance towards self-antigens and in the initiation of an effective immune response. Glucocorticoids have been widely used in the treatment of autoimmune or inflammatory disorders and their immunosuppressive effect has been mainly attributed to the inhibition of lymphocytes functions. In this study, we discuss the effects of glucocorticoids on in vitro generated myeloid dendritic cells and on peripheral blood myeloid and plasmacytoid dendritic cells subsets. Experimental results point to the profound suppressive effect of glucocorticoids on the antigen presenting functions of dendritic cells and to contribute to better understanding of glucocorticoids-mediated immunosuppressive effect.

  6. Modelling plasticity in dendrites: from single cells to networks.

    PubMed

    Bono, Jacopo; Wilmes, Katharina A; Clopath, Claudia

    2017-09-07

    One of the key questions in neuroscience is how our brain self-organises to efficiently process information. To answer this question, we need to understand the underlying mechanisms of plasticity and their role in shaping synaptic connectivity. Theoretical neuroscience typically investigates plasticity on the level of neural networks. Neural network models often consist of point neurons, completely neglecting neuronal morphology for reasons of simplicity. However, during the past decades it became increasingly clear that inputs are locally processed in the dendrites before they reach the cell body. Dendritic properties enable local interactions between synapses and location-dependent modulations of inputs, rendering the position of synapses on dendrites highly important. These insights changed our view of neurons, such that we now think of them as small networks of nearly independent subunits instead of a simple point. Here, we propose that understanding how the brain processes information strongly requires that we consider the following properties: which plasticity mechanisms are present in the dendrites and how do they enable the self-organisation of synapses across the dendritic tree for efficient information processing? Ultimately, dendritic plasticity mechanisms can be studied in networks of neurons with dendrites, possibly uncovering unknown mechanisms that shape the connectivity in our brains. Copyright © 2017. Published by Elsevier Ltd.

  7. Insights into dendritic cell function using advanced imaging modalities.

    PubMed

    Vyas, Jatin M

    2012-11-15

    The application of advanced imaging techniques to fundamental questions in immunology has provided insight into dendritic cell function and has challenged dogma created using static imaging of lymphoid tissue. The history of dendritic cell biology has a storied past and is tightly linked to imaging. The development of imaging techniques that emphasize live cell imaging in situ has provided not only breath-taking movies, but also novel insights into the importance of spatiotemporal relationships between antigen presenting cells and T cells. This review serves to provide a primer on two-photon microscopy, TIRF microscopy, spinning disk confocal microscopy and optical trapping and provides selective examples of insights gained from these tools on dendritic cell biology.

  8. T lymphocytes and dendritic cells are activated by the deletion of peroxiredoxin II (Prx II) gene.

    PubMed

    Moon, Eun-Yi; Noh, Young-Wook; Han, Ying-Hao; Kim, Sun-Uk; Kim, Jin-Man; Yu, Dae-Yeul; Lim, Jong-Seok

    2006-02-15

    Peroxiredoxin II (Prx II) is a member of antioxidant enzyme family and it plays a protective role against oxidative damage. Constitutive production of endogenous reactive oxygen species was detected in spleen and bone marrow cells lacking Prx II. Here, we investigated the role of Prx II in immune responses. The total number of splenocytes (especially, the population of S-phase cells and CD3(+) T cells) was significantly higher in Prx II(-/-) mice than in wild type. Number of peripheral blood mononuclear cells (PBMCs) in Prx II(-/-) mice was also higher than wild type. Differentiation of Prx II(-/-) mouse bone marrow cells into CD11c-positive dendritic cells was greater than that of wild type. Transplantation of Prx II(-/-) bone marrow cells into wild type mice increased PBMCs in blood and bone marrow-derived dendritic cells. Prx II deletion enhances concanavalin A (ConA)-induced splenocyte proliferation and mixed lymphocyte reaction (MLR) activity of bone marrow-derived CD11c-positive dendritic cells to stimulate recipient splenocytes. Collectively, these data suggest that Prx II inhibits the immune cell responsiveness, which may be regulated by scavenging the low amount of reactive oxygen species (ROS).

  9. S100-positive dendritic cells in squamous cell laryngeal cancer.

    PubMed

    Diaconescu, Daniela Eugenia; Dima, Lorena; Marinescu, Daniela Maria; Ţânţu, Marilena Monica; Rogozea, Liliana Marcela

    2014-01-01

    Dendritic cells (DC) are the most potent antigen-presenting cells, and induce antigen-specific immune responses. DC are believed to evolve into tumor-antigen pulsed cells and then to migrate to local lymph nodes, where they activate anti-tumor immune responses. This theory is supported by studies showing that high DC densities are associated with favorable prognosis in some tumor types. In the present study, we evaluated 40 primary and metastatic laryngeal carcinomas for the presence of DC, using immunohistochemistry with the anti-S100 protein antibody. We analyzed the relationship between the degree of infiltration by S100-positive (S100+) DC and prognostic factors, including histological subtype, histological grade, peritumor inflammatory infiltration, and stromal desmoplasia. The results show that in all evaluated laryngeal cancers S100-positive cells were significantly more frequent in the tumor stroma. Primary tumors with nodal metastases showed more significant differences in intraepithelial and stromal DC distribution than tumors without nodal metastases. A significant higher S100+ DC was also noticed in the desmoplasic stroma of lymph nodes. The subtype with keratinization had a significant higher S100-positive cells infiltration than the adenoid÷transitional subtype. The infiltration rate of intraepithelial S100+ DC was much higher in well-differentiated (G1) tumors. No significant correlation between S100-positive cells and peritumoral inflammatory infiltration and stromal desmoplasia was found. In conclusion, dendritic cells need multiple, much more complex investigations. This work should be regarded as a preliminary investigation.

  10. How Follicular Dendritic Cells Shape the B-Cell Antigenome

    PubMed Central

    Kranich, Jan; Krautler, Nike Julia

    2016-01-01

    Follicular dendritic cells (FDCs) are stromal cells residing in primary follicles and in germinal centers of secondary and tertiary lymphoid organs (SLOs and TLOs). There, they play a crucial role in B-cell activation and affinity maturation of antibodies. FDCs have the unique capacity to bind and retain native antigen in B-cell follicles for long periods of time. Therefore, FDCs shape the B-cell antigenome (the sum of all B-cell antigens) in SLOs and TLOs. In this review, we discuss recent findings that explain how this stromal cell type can arise in almost any tissue during TLO formation and, furthermore, focus on the mechanisms of antigen capture and retention involved in the generation of long-lasting antigen depots displayed on FDCs. PMID:27446069

  11. Remodeling of the dendritic structure of the striatal medium spiny neurons accompanies behavioral recovery in a mouse model of Parkinson's disease.

    PubMed

    Kim, Wonju; Im, Mi Jung; Park, Cheol Hyoung; Lee, C Justin; Choi, Sukwoo; Yoon, Bong-June

    2013-12-17

    Medium spiny neurons (MSNs) are the major type of neurons found in the striatum. The dendritic spines on these cells contain glutamatergic synaptic contacts between the cortex (or the thalamus) and the striatum. The complexity of the dendritic structure of MSNs may therefore reflect the functional status of the basal ganglia because the striatum is the major input structure in which signals from different regions are integrated. We examined the structural alterations in the dendrites of striatal MSNs in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease (PD). Acute MPTP treatment rapidly damaged dopaminergic neurons and their terminals within the striatum and caused behavioral impairments. However, mice injected with MPTP spontaneously recovered from these behavioral impairments within one week. This recovery was accompanied by the restoration of dendritic structures on MSNs, but the damage to dopaminergic neurons remained extensive. Furthermore, we demonstrated that rasagiline, a monoamine oxidase-B (MAO-B) inhibitor that has been shown to be efficacious for PD, could enhance the dendritic complexity of cultured MSNs. The effect of rasagiline on the spine-like structures of dendrites, however, appears not to require DA availability because the small protrusions of dendrites in cultured MSNs without major source of DA input was similarly changed by rasagiline. Our data suggest that the dendritic structures of striatal MSNs change dynamically, reflecting the progression of motor-related symptoms in PD, and the restoration of functional synapses in the MSNs of PD patients may constitute a clinical target for symptomatic alleviation.

  12. Retrospection to discovery of bursal function and recognition of avian dendritic cells; past and present.

    PubMed

    Oláh, Imre; Nagy, Nándor

    2013-11-01

    In 1954 the discovery of bursal function was one of the major contributions to the formation of the T and B cell concept of immunology. In 1978 the avian dendritic cells; bursal secretory dendritic cell (BSDC) and follicular dendritic cell (FDC) in the cecal tonsil were recognized. In 1982 the interdigitating dendritic cell was described in the periarteriolar lymphatic sheath (PALS) of the spleen. This paper is a retrospection of the stories of the discovery of bursal function and recognition of avian dendritic cells and includes the markers which can be used for monitoring and characterizing avian dendritic cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Macrophages as APC and the dendritic cell myth.

    PubMed

    Hume, David A

    2008-11-01

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

  14. Drinking a lot is good for dendritic cells

    PubMed Central

    Norbury, Christopher C

    2006-01-01

    Macropinocytosis is the actin-dependent formation of large vesicles, which allow the internalization of large quantities of fluid-phase solute. In the majority of cells examined, an exogenous stimulus is required to induce the initiation of this endocytic pathway. However, dendritic cells are thought to constitutively macropinocytose large quantities of exogenous solute as part of their sentinel function. In this review we discuss the evidence that dendritic cells macropinocytose exogenous solute and subsequently present antigenic peptides derived from internalized material to T cells. In addition, we put these data into the context of immune surveillance in vivo. PMID:16556257

  15. Sodium action potentials in the dendrites of cerebellar Purkinje cells.

    PubMed

    Regehr, W G; Konnerth, A; Armstrong, C M

    1992-06-15

    We report here that in cerebellar Purkinje cells from which the axon has been removed, positive voltage steps applied to the voltage-clamped soma produce spikes of active current. The spikes are inward, are all-or-none, have a duration of approximately 1 ms, and are reversibly eliminated by tetrodotoxin, a Na channel poison. From cell to cell, the amplitude of the spikes ranges from 4 to 20 nA. Spike latency decreases as the depolarizing step is made larger. These spikes clearly arise at a site where the voltage is not controlled, remote from the soma. From these facts we conclude that Purkinje cell dendrites contain a sufficient density of Na channels to generate action potentials. Activation by either parallel fiber or climbing fiber synapses produces similar spikes, suggesting that normal input elicits Na action potentials in the dendrites. These findings greatly alter current views of how dendrites in these cells respond to synaptic input.

  16. Murid Herpesvirus-4 Exploits Dendritic Cells to Infect B Cells

    PubMed Central

    Frederico, Bruno; Gill, Michael B.; Smith, Christopher M.; Belz, Gabrielle T.; Stevenson, Philip G.

    2011-01-01

    Dendritic cells (DCs) play a central role in initiating immune responses. Some persistent viruses infect DCs and can disrupt their functions in vitro. However, these viruses remain strongly immunogenic in vivo. Thus what role DC infection plays in the pathogenesis of persistent infections is unclear. Here we show that a persistent, B cell-tropic gamma-herpesvirus, Murid Herpesvirus-4 (MuHV-4), infects DCs early after host entry, before it establishes a substantial infection of B cells. DC-specific virus marking by cre-lox recombination revealed that a significant fraction of the virus latent in B cells had passed through a DC, and a virus attenuated for replication in DCs was impaired in B cell colonization. In vitro MuHV-4 dramatically altered the DC cytoskeleton, suggesting that it manipulates DC migration and shape in order to spread. MuHV-4 therefore uses DCs to colonize B cells. PMID:22102809

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

    PubMed

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

    2016-01-01

    Dendritic cell (DC) migration is essential for efficient host defense against pathogens and cancer, as well as for the efficacy of DC-based immunotherapies. However, the molecules that induce the migratory phenotype of DCs are poorly defined. Based on a large-scale proteome analysis of maturing DCs, we identified the GPI-anchored protein semaphorin 7A (Sema7A) as being highly expressed on activated primary myeloid and plasmacytoid DCs in human and mouse. We demonstrate that Sema7A deficiency results in impaired chemokine CCL21-driven DC migration in vivo. Impaired formation of actin-based protrusions, resulting in slower three-dimensional migration, was identified as the mechanism underlying the DC migration defect. Furthermore, we show, by atomic force microscopy, that Sema7A decreases adhesion strength to extracellular matrix while increasing the connectivity of adhesion receptors to the actin cytoskeleton. This study demonstrates that Sema7A controls the assembly of actin-based protrusions that drive DC migration in response to CCL21. Copyright © 2015 by The American Association of Immunologists, Inc.

  18. Dendritic spine instability leads to progressive neocortical spine loss in a mouse model of Huntington's disease.

    PubMed

    Murmu, Reena Prity; Li, Wen; Holtmaat, Anthony; Li, Jia-Yi

    2013-08-07

    In Huntington's disease (HD), cognitive symptoms and cellular dysfunction precede the onset of classical motor symptoms and neuronal death in the striatum and cortex by almost a decade. This suggests that the early cognitive deficits may be due to a cellular dysfunction rather than being a consequence of neuronal loss. Abnormalities in dendritic spines are described in HD patients and in HD animal models. Available evidence indicates that altered spine and synaptic plasticity could underlie the motor as well as cognitive symptoms in HD. However, the exact kinetics of spine alterations and plasticity in HD remain unknown. We used long-term two-photon imaging through a cranial window, to track individual dendritic spines in a mouse model of HD (R6/2) as the disease progressed. In vivo imaging over a period of 6 weeks revealed a steady decrease in the density and survival of dendritic spines on cortical neurons of R6/2 mice compared with control littermates. Interestingly, we also observed increased spine formation in R6/2 mice throughout the disease. However, the probability that newly formed spines stabilized and transformed into persistent spines was greatly reduced compared with controls. In cultured neurons we found that mutant huntingtin causes a loss, in particular of mature spines. Furthermore, in R6/2 mice, aggregates of mutant huntingtin associate with dendritic spines. Alterations in dendritic spine dynamics, survival, and density in R6/2 mice were evident before the onset of motor symptoms, suggesting that decreased stability of the cortical synaptic circuitry underlies the early symptoms in HD.

  19. The Mucosal Adjuvant Cyclic di-AMP Exerts Immune Stimulatory Effects on Dendritic Cells and Macrophages

    PubMed Central

    Libanova, Rimma; Lienenklaus, Stefan; Weiss, Siegfried; Guzmán, Carlos A.

    2014-01-01

    The cyclic di-nucleotide bis-(3′,5′)-cyclic dimeric adenosine monophosphate (c-di-AMP) is a candidate mucosal adjuvant with proven efficacy in preclinical models. It was shown to promote specific humoral and cellular immune responses following mucosal administration. To date, there is only fragmentary knowledge on the cellular and molecular mode of action of c-di-AMP. Here, we report on the identification of dendritic cells and macrophages as target cells of c-di-AMP. We show that c-di-AMP induces the cell surface up-regulation of T cell co-stimulatory molecules as well as the production of interferon-β. Those responses were characterized by in vitro experiments with murine and human immune cells and in vivo studies in mice. Analyses of dendritic cell subsets revealed conventional dendritic cells as principal responders to stimulation by c-di-AMP. We discuss the impact of the reported antigen presenting cell activation on the previously observed adjuvant effects of c-di-AMP in mouse immunization studies. PMID:24755640

  20. Up-regulation of HP1γ expression during neuronal maturation promotes axonal and dendritic development in mouse embryonic neocortex.

    PubMed

    Oshiro, Hiroaki; Hirabayashi, Yusuke; Furuta, Yasuhide; Okabe, Shigeo; Gotoh, Yukiko

    2015-02-01

    Immature neurons undergo morphological and physiological changes including axonal and dendritic development to establish neuronal networks. As the transcriptional status changes at a large number of genes during neuronal maturation, global changes in chromatin modifiers may take place in this process. We now show that the amount of heterochromatin protein 1γ (HP1γ) increases during neuronal maturation in the mouse neocortex. Knockdown of HP1γ suppressed axonal and dendritic development in mouse embryonic neocortical neurons in culture, and either knockdown or knockout of HP1γ impaired the projection of callosal axons of superficial layer neurons to the contralateral hemisphere in the developing neocortex. Conversely, forced expression of HP1γ facilitated axonal and dendritic development, suggesting that the increase of HP1γ is a rate limiting step in neuronal maturation. These results together show an important role for HP1γ in promoting axonal and dendritic development in maturing neurons.

  1. Genetic tracing via DNGR-1 expression history defines dendritic cells as a hematopoietic lineage.

    PubMed

    Schraml, Barbara U; van Blijswijk, Janneke; Zelenay, Santiago; Whitney, Paul G; Filby, Andrew; Acton, Sophie E; Rogers, Neil C; Moncaut, Natalia; Carvajal, Jaime J; Reis e Sousa, Caetano

    2013-08-15

    Mononuclear phagocytes are classified as macrophages or dendritic cells (DCs) based on cell morphology, phenotype, or select functional properties. However, these attributes are not absolute and often overlap, leading to difficulties in cell-type identification. To circumvent this issue, we describe a mouse model to define DCs based on their ontogenetic descendence from a committed precursor. We show that precursors of mouse conventional DCs, but not other leukocytes, are marked by expression of DNGR-1. Genetic tracing of DNGR-1 expression history specifically marks cells traditionally ascribed to the DC lineage, and this restriction is maintained after inflammation. Notably, in some tissues, cells previously thought to be monocytes/macrophages are in fact descendants from DC precursors. These studies provide an in vivo model for fate mapping of DCs, distinguishing them from other leukocyte lineages, and thus help to unravel the functional complexity of the mononuclear phagocyte system. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Effect of aging and oral tolerance on dendritic cell function.

    PubMed

    Simioni, P U; Fernandes, L G R; Gabriel, D L; Tamashiro, W M S C

    2010-01-01

    Oral tolerance can be induced in some mouse strains by gavage or spontaneous ingestion of dietary antigens. In the present study, we determined the influence of aging and oral tolerance on the secretion of co-stimulatory molecules by dendritic cells (DC), and on the ability of DC to induce proliferation and cytokine secretion by naive T cells from BALB/c and OVA transgenic (DO11.10) mice. We observed that oral tolerance could be induced in BALB/c mice (N = 5 in each group) of all ages (8, 20, 40, 60, and 80 weeks old), although a decline in specific antibody levels was observed in the sera of both tolerized and immunized mice with advancing age (40 to 80 weeks old). DC obtained from young, adult and middle-aged (8, 20, and 40 weeks old) tolerized mice were less efficient (65, 17 and 20%, respectively) than DC from immunized mice (P < 0.05) in inducing antigen-specific proliferation of naive T cells from both BALB/c and DO11.10 young mice, or in stimulating IFN-g, IL-4 and IL-10 production. However, TGF-beta levels were significantly elevated in co-cultures carried out with DC from tolerant mice (P < 0.05). DC from both immunized and tolerized old and very old (60 and 80 weeks old) mice were equally ineffective in inducing T cell proliferation and cytokine production (P < 0.05). A marked reduction in CD86+ marker expression was observed in DC isolated from both old and tolerized mice (75 and 50%, respectively). The results indicate that the aging process does not interfere with the establishment of oral tolerance in BALB/c mice, but reduces DC functions, probably due to the decline of the expression of the CD86 surface marker.

  3. Dendritic cells: a family portrait at mid-gestation

    PubMed Central

    Bizargity, Peyman; Bonney, Elizabeth A

    2009-01-01

    Recent advances in our understanding of dendritic cells (DCs) and their role in tolerance and immunity has fuelled study of their normal development and function within the reproductive tract. The common hypothesis that pregnancy is a state of immune suppression or deviation now includes the idea that alterations in DC phenotype and function are critical for maternal tolerance. We chose to study DCs in the uterus and lymphoid tissue in non-pregnant and pregnant mice at mid-gestation to understand what DC-related factors may be involved in premature birth. We used a mouse model where the mother’s immune system has been shown to respond to the male antigen H-Y. Observed differences among DCs in the uterus, uterine draining nodes and spleen, even in non-pregnant mice, suggest the existence of a specialized uterus-specific subset of DCs. We further found that, amongst CD45+ CD11c+ cells in the uterus and peripheral lymphoid tissue of pregnant mice, expression of major histocompatibility complex class II (MHC II) and costimulatory molecules (i.e. CD80) was similar to that in the non-pregnant state. Moreover, there was no pregnancy-related decrease in the proportion of CD11c+ cells in the uterus or in the uterine node that were CD11b− CD8+. Pregnancy increased the CD11b+ subsets and the expression of chemokine (C-C motif) ligand 6 (CCL6) in DCs of the uterine draining nodes. Finally, DC subsets showed variable expression, with respect to tissue and pregnancy, of the cytokine interleukin-15, which is important in lymphoid cell homeostasis. For DCs, pregnancy is not a state of immune paralysis, but of dynamic developmental change. PMID:18778288

  4. Chitosan Interferon-γ Nanogene Therapy for Lung Disease: Modulation of T-Cell and Dendritic Cell Immune Responses

    PubMed Central

    2008-01-01

    The use of chitosan nanoparticles as carriers for expression plasmids represents a major improvement in gene expression technology. We demonstrated previously that treatment with chitosan interferon-γ (IFN-γ) plasmid deoxyribonucleic acid (DNA) nanoparticles (chitosan interferon-γ nanogene [CIN]) led to in situ production of IFN-γ and a reduction in inflammation and airway reactivity in mice, but the mechanism underlying the immunomodulatory effects of CIN remains unclear. In this report, the effect of CIN treatment on the immune responses of CD8+ T cells and dendritic cells was examined in a BALB/c mouse model of ovalbumin (OVA)-induced allergic asthma. OT1 mice (OVA-T cell receptor [TCR] transgenic) were also used to test the effects of CIN on OVA-specific CD8+ T cells. CIN treatment caused a reduction in IFN-γ production in a subpopulation of OVA-specific CD8+ T cells cultured in vitro in the presence of OVA. CIN also reduced apoptosis of the CD8+ T cells. Examination of dendritic cells from lung and lymph nodes indicated that CIN treatment decreased their antigen-presenting activity, as evident from the reduction in CD80 and CD86 expression. Furthermore, CIN treatment significantly decreased the number of CD11c+b+ dendritic cells in lymph nodes, suggesting that endogenous IFN-γ expression may immunomodulate dendritic cell migration and activation. CIN therapy results in a reduction in proinflammatory CD8+ T cells and decreases the number and antigen-presenting activity of dendritic cells. PMID:20525130

  5. Autophagy gene Atg16L1 prevents lethal T cell alloreactivity mediated by dendritic cells.

    PubMed

    Hubbard-Lucey, Vanessa M; Shono, Yusuke; Maurer, Katie; West, Mallory L; Singer, Natalie V; Ziegler, Carly G K; Lezcano, Cecilia; Motta, Ana Carolina Fragoso; Schmid, Karin; Levi, Samuel M; Murphy, George F; Liu, Chen; Winkler, Jeffrey D; Amaravadi, Ravi K; Rogler, Gerhard; Dickinson, Anne M; Holler, Ernst; van den Brink, Marcel R M; Cadwell, Ken

    2014-10-16

    Atg16L1 mediates the cellular degradative process of autophagy and is considered a critical regulator of inflammation based on its genetic association with inflammatory bowel disease. Here we find that Atg16L1 deficiency leads to an exacerbated graft-versus-host disease (GVHD) in a mouse model of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Atg16L1-deficient allo-HSCT recipients with GVHD displayed increased T cell proliferation due to increased dendritic cell (DC) numbers and costimulatory molecule expression. Reduced autophagy within DCs was associated with lysosomal abnormalities and decreased amounts of A20, a negative regulator of DC activation. These results broaden the function of Atg16L1 and the autophagy pathway to include a role in limiting a DC-mediated response during inflammatory disease, such as GVHD.

  6. Autophagy gene Atg16l1 prevents lethal T cell alloreactivity mediated by dendritic cells

    PubMed Central

    Hubbard-Lucey, Vanessa M.; Shono, Yusuke; Maurer, Katie; West, Mallory L.; Singer, Natalie V.; Ziegler, Carly G. K.; Lezcano, Cecilia; Motta, Ana Carolina Fragoso; Schmid, Karin; Levi, Samuel M.; Murphy, George F.; Liu, Chen; Winkler, Jeffrey D.; Amaravadi, Ravi K.; Rogler, Gerhard; Dickinson, Anne M.; Holler, Ernst; van den Brink, Marcel RM; Cadwell, Ken

    2014-01-01

    SUMMARY Atg16L1 mediates the cellular degradative process of autophagy and is considered a critical regulator of inflammation based on its genetic association with inflammatory bowel disease. Here we find that Atg16L1 deficiency leads to an exacerbated graft-versus-host disease (GVHD) in a mouse model of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Atg16L1-deficient allo-HSCT recipients with GVHD displayed increased T cell proliferation due to increased dendritic cell (DC) numbers and co-stimulatory molecule expression. Reduced autophagy within DCs was associated with lysosomal abnormalities and decreased amounts of A20, a negative regulator of DC activation. These results broaden the function of Atg16L1 and the autophagy pathway to include a role in limiting a DC-mediated response during inflammatory disease, such as GVHD. PMID:25308334

  7. Phenotypic and functional profiling of mouse intestinal antigen presenting cells

    PubMed Central

    Harusato, Akihito; Flannigan, Kyle L.; Geem, Duke; Denning, Timothy L.

    2015-01-01

    The microbiota that populates the mammalian intestine consists of hundreds of trillions of bacteria that are separated from underlying immune cells by a single layer of epithelial cells. The intestinal immune system effectively tolerates components of the microbiota that provide benefit to the host while remaining poised to eliminate those that are harmful. Antigen presenting cells, especially macrophages and dendritic cells, play important roles in maintaining intestinal homeostasis via their ability to orchestrate appropriate responses to the microbiota. Paramount to elucidating intestinal macrophage- and dendritic cell-mediated functions is the ability to effectively isolate and identify these cells from a complex cellular environment. In this review, we summarize methodology for the isolation and phenotypic characterization of macrophages and DCs from the mouse intestine and discuss how this may be useful for gaining insight into the mechanisms by which mucosal immune tolerance is maintained. PMID:25891794

  8. Bone marrow plasmacytoid dendritic cells can differentiate into myeloid dendritic cells upon virus infection

    PubMed Central

    Zuniga, Elina I; McGavern, Dorian B; Pruneda-Paz, Jose L; Teng, Chao; Oldstone, Michael B A

    2017-01-01

    Two subsets of dendritic cell (DCs), plasmacytoid (p) and myeloid (m) DCs, have been described in humans and mice. These subsets are known to have divergent roles during an immune response, but their developmental course is unclear. Here we report that virus infection induces bone marrow pDCs to differentiate into mDCs, thereby undergoing profound phenotypic and functional changes including the acquisition of enhanced antigen-presenting capacity and the ability to recognize different microbial structures through Toll-like receptor 4. The conversion of pDCs into mDCs is also induced by the injection of double-stranded RNA and requires type I interferons. Our results establish a precursor-product developmental relationship between these two DC subsets and highlight unexpected plasticity of bone marrow pDCs. PMID:15531885

  9. Toll-like receptor-4 agonist in post-haemorrhage pneumonia: role of dendritic and natural killer cells.

    PubMed

    Roquilly, Antoine; Broquet, Alexis; Jacqueline, Cedric; Gautreau, Laetitia; Segain, Jean Pierre; de Coppet, Pierre; Caillon, Jocelyne; Altare, Frédéric; Josien, Regis; Asehnoune, Karim

    2013-11-01

    Haemorrhage-induced immunosuppression has been linked to nosocomial infections. We assessed the impact of monophosphoryl lipid A, a Toll/interleukin-1 receptor-domain-containing adaptor protein inducing interferon-biased Toll-like receptor-4 agonist currently used as a vaccine adjuvant in humans, on post-haemorrhage susceptibility to infection. We used a mouse model of post-haemorrhage pneumonia induced by methicillin-susceptible Staphylococcus aureus. Monophosphoryl lipid A was administered intravenously after haemorrhage and before pneumonia onset. Haemorrhage altered survival rate, increased lung damage (neutrophil accumulation, oedema and cytokine release) and altered the functions of dendritic and natural killer cells. Here, we show that monophosphoryl lipid A decreased systemic dissemination of S. aureus and dampened inflammatory lung lesions. Monophosphoryl lipid A partially restored the capacity for antigen presentation and the transcriptional activity in dendritic cells. Monophosphoryl lipid A did not restore the interferon-γ mRNA but prevented interleukin-10 mRNA overexpression in natural killer cells compared with untreated mice. Ex vivo monophosphoryl lipid A-stimulated dendritic cells or natural killer cells harvested from haemorrhaged animals were adoptively transferred into mice undergoing post-haemorrhage pneumonia. Stimulated dendritic cells (but not stimulated natural killer cells) improved the survival rate compared with mice left untreated. In vivo depletion of natural killer cells decreased survival rate of monophosphoryl lipid A-treated mice. Dendritic and natural killer cells are critically involved in the beneficial effects of monophosphoryl lipid A within post-haemorrhage pneumonia.

  10. Functions of TGF-β-exposed plasmacytoid dendritic cells.

    PubMed

    Saas, Philippe; Perruche, Sylvain

    2012-01-01

    Plasmacytoid dendritic cells (pDCs) belong to the family of dendritic cells and possess specific features that distinguish them from conventional dendritic cells. For instance, pDC are the main interferon-alpha-secreting cells. Plasmacytoid dendritic cells exert both proinflammatory and regulatory functions. This is attested by the involvement of pDC through interferon-alpha secretion in several autoimmune diseases, and by the implication of pDC in tolerance. The same is true for TGF-β that plays a dual role in inflammation. In this review, we discuss recent data on pDC and TGF-β interactions. As with many cell types, pDCs are able to respond to TGF-β using the classic Smad signaling pathway. In addition, pDCs are capable to secrete TGF-β, in particular in response to TGF-β exposure. Exposure of pDCs to TGF-β prevents type I interferon secretion in response to TLR7/9 ligands. In contrast, the consequences of TGF-β on the antigen-presenting cell capacities of pDC are less clear, since TGF-β-exposed pDCs may lead to both regulatory T-cell and interleukin-17-secreting cell polarization. Here, we discuss the factors that may influence this polarization. We also discuss how pDCs exposed to TGF-β may participate in tolerance induction and maintenance, or, on the contrary, in autoimmune diseases.

  11. Angioimmunoblastic T-Cell Lymphoma: A Questionable Association with Follicular Dendritic Cell Sarcoma

    PubMed Central

    Zekzer, Miriam; Nalbandyan, Karen

    2017-01-01

    An elderly woman presented with generalized lymphadenopathy, several systemic symptoms, and splenomegaly. An inguinal lymph node excision revealed a compound picture. One aspect of the lymph node morphology, including cells with follicular T-helper cell phenotype, was most consistent with angioimmunoblastic T-cell lymphoma. The other component, revealing spindle cells forming whorls with immunostaining for CD21, CD23, and fascin, might be an integral part of this T-cell lymphoma. However, due to the often massive involvement of the nodal tissue by these follicular dendritic cells, these areas were questionably suggestive of involvement by follicular dendritic cell sarcoma. We raise herein the issue of the borderline area between advanced follicular dendritic cell expansion in angioimmunoblastic T-cell lymphoma and a massive follicular dendritic cell proliferation consistent with follicular dendritic cells sarcoma, in the absence of a genomic analysis. PMID:28197348

  12. Alterations to dendritic spine morphology, but not dendrite patterning, of cortical projection neurons in Tc1 and Ts1Rhr mouse models of Down syndrome.

    PubMed

    Haas, Matilda A; Bell, Donald; Slender, Amy; Lana-Elola, Eva; Watson-Scales, Sheona; Fisher, Elizabeth M C; Tybulewicz, Victor L J; Guillemot, François

    2013-01-01

    Down Syndrome (DS) is a highly prevalent developmental disorder, affecting 1/700 births. Intellectual disability, which affects learning and memory, is present in all cases and is reflected by below average IQ. We sought to determine whether defective morphology and connectivity in neurons of the cerebral cortex may underlie the cognitive deficits that have been described in two mouse models of DS, the Tc1 and Ts1Rhr mouse lines. We utilised in utero electroporation to label a cohort of future upper layer projection neurons in the cerebral cortex of developing mouse embryos with GFP, and then examined neuronal positioning and morphology in early adulthood, which revealed no alterations in cortical layer position or morphology in either Tc1 or Ts1Rhr mouse cortex. The number of dendrites, as well as dendrite length and branching was normal in both DS models, compared with wildtype controls. The sites of projection neuron synaptic inputs, dendritic spines, were analysed in Tc1 and Ts1Rhr cortex at three weeks and three months after birth, and significant changes in spine morphology were observed in both mouse lines. Ts1Rhr mice had significantly fewer thin spines at three weeks of age. At three months of age Tc1 mice had significantly fewer mushroom spines--the morphology associated with established synaptic inputs and learning and memory. The decrease in mushroom spines was accompanied by a significant increase in the number of stubby spines. This data suggests that dendritic spine abnormalities may be a more important contributor to cognitive deficits in DS models, rather than overall neuronal architecture defects.

  13. Alterations to Dendritic Spine Morphology, but Not Dendrite Patterning, of Cortical Projection Neurons in Tc1 and Ts1Rhr Mouse Models of Down Syndrome

    PubMed Central

    Haas, Matilda A.; Bell, Donald; Slender, Amy; Lana-Elola, Eva; Watson-Scales, Sheona; Fisher, Elizabeth M. C.; Tybulewicz, Victor L. J.; Guillemot, François

    2013-01-01

    Down Syndrome (DS) is a highly prevalent developmental disorder, affecting 1/700 births. Intellectual disability, which affects learning and memory, is present in all cases and is reflected by below average IQ. We sought to determine whether defective morphology and connectivity in neurons of the cerebral cortex may underlie the cognitive deficits that have been described in two mouse models of DS, the Tc1 and Ts1Rhr mouse lines. We utilised in utero electroporation to label a cohort of future upper layer projection neurons in the cerebral cortex of developing mouse embryos with GFP, and then examined neuronal positioning and morphology in early adulthood, which revealed no alterations in cortical layer position or morphology in either Tc1 or Ts1Rhr mouse cortex. The number of dendrites, as well as dendrite length and branching was normal in both DS models, compared with wildtype controls. The sites of projection neuron synaptic inputs, dendritic spines, were analysed in Tc1 and Ts1Rhr cortex at three weeks and three months after birth, and significant changes in spine morphology were observed in both mouse lines. Ts1Rhr mice had significantly fewer thin spines at three weeks of age. At three months of age Tc1 mice had significantly fewer mushroom spines - the morphology associated with established synaptic inputs and learning and memory. The decrease in mushroom spines was accompanied by a significant increase in the number of stubby spines. This data suggests that dendritic spine abnormalities may be a more important contributor to cognitive deficits in DS models, rather than overall neuronal architecture defects. PMID:24205261

  14. Fragile X related protein 1 clusters with ribosomes and messenger RNAs at a subset of dendritic spines in the mouse hippocampus.

    PubMed

    Cook, Denise; Sanchez-Carbente, Maria del Rayo; Lachance, Claude; Radzioch, Danuta; Tremblay, Sandra; Khandjian, Edouard W; DesGroseillers, Luc; Murai, Keith K

    2011-01-01

    The formation and storage of memories in neuronal networks relies on new protein synthesis, which can occur locally at synapses using translational machinery present in dendrites and at spines. These new proteins support long-lasting changes in synapse strength and size in response to high levels of synaptic activity. To ensure that proteins are made at the appropriate time and location to enable these synaptic changes, messenger RNA (mRNA) translation is tightly controlled by dendritic RNA-binding proteins. Fragile X Related Protein 1 (FXR1P) is an RNA-binding protein with high homology to Fragile X Mental Retardation Protein (FMRP) and is known to repress and activate mRNA translation in non-neuronal cells. However, unlike FMRP, very little is known about the role of FXR1P in the central nervous system. To understand if FXR1P is positioned to regulate local mRNA translation in dendrites and at synapses, we investigated the expression and targeting of FXR1P in developing hippocampal neurons in vivo and in vitro. We found that FXR1P was highly expressed during hippocampal development and co-localized with ribosomes and mRNAs in the dendrite and at a subset of spines in mouse hippocampal neurons. Our data indicate that FXR1P is properly positioned to control local protein synthesis in the dendrite and at synapses in the central nervous system.

  15. Apoptotic cell-treated dendritic cells induce immune tolerance by specifically inhibiting development of CD4⁺ effector memory T cells.

    PubMed

    Zhou, Fang; Zhang, Guang-Xian; Rostami, Abdolmohamad

    2016-02-01

    CD4(+) memory T cells play an important role in induction of autoimmunity and chronic inflammatory responses; however, regulatory mechanisms of CD4(+) memory T cell-mediated inflammatory responses are poorly understood. Here we show that apoptotic cell-treated dendritic cells inhibit development and differentiation of CD4(+) effector memory T cells in vitro and in vivo. Simultaneously, intravenous transfer of apoptotic T cell-induced tolerogenic dendritic cells can block development of experimental autoimmune encephalomyelitis (EAE), an inflammatory disease of the central nervous system in C57 BL/6J mouse. Our results imply that it is effector memory CD4(+) T cells, not central memory CD4(+) T cells, which play a major role in chronic inflammatory responses in mice with EAE. Intravenous transfer of tolerogenic dendritic cells induced by apoptotic T cells leads to immune tolerance by specifically blocking development of CD4(+) effector memory T cells compared with results of EAE control mice. These results reveal a new mechanism of apoptotic cell-treated dendritic cell-mediated immune tolerance in vivo.

  16. Cell-Autonomous Regulation of Dendritic Spine Density by PirB

    PubMed Central

    2016-01-01

    Synapse density on cortical pyramidal neurons is modulated by experience. This process is highest during developmental critical periods, when mechanisms of synaptic plasticity are fully engaged. In mouse visual cortex, the critical period for ocular dominance (OD) plasticity coincides with the developmental pruning of synapses. At this time, mice lacking paired Ig-like receptor B (PirB) have excess numbers of dendritic spines on L5 neurons; these spines persist and are thought to underlie the juvenile-like OD plasticity observed in adulthood. Here we examine whether PirB is required specifically in excitatory neurons to exert its effect on dendritic spine and synapse density during the critical period. In mice with a conditional allele of PirB (PirBfl/fl), PirB was deleted only from L2/3 cortical pyramidal neurons in vivo by timed in utero electroporation of Cre recombinase. Sparse mosaic expression of Cre produced neurons lacking PirB in a sea of wild-type neurons and glia. These neurons had significantly elevated dendritic spine density, as well as increased frequency of miniature EPSCs, suggesting that they receive a greater number of synaptic inputs relative to Cre– neighbors. The effect of cell-specific PirB deletion on dendritic spine density was not accompanied by changes in dendritic branching complexity or axonal bouton density. Together, results imply a neuron-specific, cell-autonomous action of PirB on synaptic density in L2/3 pyramidal cells of visual cortex. Moreover, they are consistent with the idea that PirB functions normally to corepress spine density and synaptic plasticity, thereby maintaining headroom for cells to encode ongoing experience-dependent structural change throughout life. PMID:27752542

  17. Cell-Autonomous Regulation of Dendritic Spine Density by PirB.

    PubMed

    Vidal, George S; Djurisic, Maja; Brown, Kiana; Sapp, Richard W; Shatz, Carla J

    2016-01-01

    Synapse density on cortical pyramidal neurons is modulated by experience. This process is highest during developmental critical periods, when mechanisms of synaptic plasticity are fully engaged. In mouse visual cortex, the critical period for ocular dominance (OD) plasticity coincides with the developmental pruning of synapses. At this time, mice lacking paired Ig-like receptor B (PirB) have excess numbers of dendritic spines on L5 neurons; these spines persist and are thought to underlie the juvenile-like OD plasticity observed in adulthood. Here we examine whether PirB is required specifically in excitatory neurons to exert its effect on dendritic spine and synapse density during the critical period. In mice with a conditional allele of PirB (PirB(fl/fl)), PirB was deleted only from L2/3 cortical pyramidal neurons in vivo by timed in utero electroporation of Cre recombinase. Sparse mosaic expression of Cre produced neurons lacking PirB in a sea of wild-type neurons and glia. These neurons had significantly elevated dendritic spine density, as well as increased frequency of miniature EPSCs, suggesting that they receive a greater number of synaptic inputs relative to Cre(-) neighbors. The effect of cell-specific PirB deletion on dendritic spine density was not accompanied by changes in dendritic branching complexity or axonal bouton density. Together, results imply a neuron-specific, cell-autonomous action of PirB on synaptic density in L2/3 pyramidal cells of visual cortex. Moreover, they are consistent with the idea that PirB functions normally to corepress spine density and synaptic plasticity, thereby maintaining headroom for cells to encode ongoing experience-dependent structural change throughout life.

  18. Distinct behavior of human Langerhans cells and inflammatory dendritic epidermal cells at tight junctions in patients with atopic dermatitis.

    PubMed

    Yoshida, Kazue; Kubo, Akiharu; Fujita, Harumi; Yokouchi, Mariko; Ishii, Ken; Kawasaki, Hiroshi; Nomura, Toshifumi; Shimizu, Hiroshi; Kouyama, Keisuke; Ebihara, Tamotsu; Nagao, Keisuke; Amagai, Masayuki

    2014-10-01

    The stratum corneum and tight junctions (TJs) form physical barriers in the epidermis. Dendrites of activated Langerhans cells (LCs) extend beyond the TJs to capture external antigens in mice. LCs and inflammatory dendritic epidermal cells (IDECs) are observed in the skin of patients with atopic dermatitis (AD). We sought to investigate the characteristics of LCs and IDECs and the distribution of their antigen capture receptors in relation to TJs in normal and AD skin. We characterized the interactions of LCs and IDECs with TJs and the expression patterns of langerin and FcεRI by using whole-mount epidermal sheets from healthy subjects and patients with AD, ichthyosis vulgaris, and psoriasis vulgaris. As in mouse skin, activated LCs penetrate TJs in human skin. The number of LCs with TJ penetration increased approximately 5-fold in erythematous lesional skin of patients with AD but not in nonlesional skin of patients with AD or lesions of patients with ichthyosis vulgaris or psoriasis. In contrast, IDECs localized in the lower part of the epidermis, and their dendrites extended horizontally without penetration through TJs. Although langerin accumulated on the tips of dendrites of activated LCs, FcεRI was expressed diffusely on the cell surfaces on LCs and IDECs in lesional skin from patients with AD. These findings highlight interesting differences between LCs and IDECs in epidermis of patients with AD, where LCs, but not IDECs, extend dendrites through the TJs, likely to capture antigens from outside the TJ barrier with a polarized distribution of langerin but not FcεRI. These behavioral differences between skin dendritic cells might reflect an important pathophysiology of AD. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  19. Reprogramming Neutral Lipid Metabolism in Mouse Dendritic Leucocytes Hosting Live Leishmania amazonensis Amastigotes

    PubMed Central

    Lecoeur, Hervé; Giraud, Emilie; Prévost, Marie-Christine; Milon, Geneviève; Lang, Thierry

    2013-01-01

    Background After loading with live Leishmania (L) amazonensis amastigotes, mouse myeloid dendritic leucocytes/DLs are known to undergo reprogramming of their immune functions. In the study reported here, we investigated whether the presence of live L. amazonensis amastigotes in mouse bone marrow-derived DLs is able to trigger re-programming of DL lipid, and particularly neutral lipid metabolism. Methodology/Principal Findings Affymetrix-based transcriptional profiles were determined in C57BL/6 and DBA/2 mouse bone marrow-derived DLs that had been sorted from cultures exposed or not to live L. amazonensis amastigotes. This showed that live amastigote-hosting DLs exhibited a coordinated increase in: (i) long-chain fatty acids (LCFA) and cholesterol uptake/transport, (ii) LCFA and cholesterol (re)-esterification to triacyl-sn-glycerol (TAG) and cholesteryl esters (CE), respectively. As these neutral lipids are known to make up the lipid body (LB) core, oleic acid was added to DL cultures and LB accumulation was compared in live amastigote-hosting versus amastigote-free DLs by epi-fluorescence and transmission electron microscopy. This showed that LBs were both significantly larger and more numerous in live amastigote-hosting mouse dendritic leucocytes. Moreover, many of the larger LB showed intimate contact with the membrane of the parasitophorous vacuoles hosting the live L. amazonensis amastigotes. Conclusions/Significance As leucocyte LBs are known to be more than simple neutral lipid repositories, we set about addressing two related questions. Could LBs provide lipids to live amastigotes hosted within the DL parasitophorous vacuole and also deliver? Could LBs impact either directly or indirectly on the persistence of L. amazonensis amastigotes in rodent skin? PMID:23785538

  20. Reprogramming neutral lipid metabolism in mouse dendritic leucocytes hosting live Leishmania amazonensis amastigotes.

    PubMed

    Lecoeur, Hervé; Giraud, Emilie; Prévost, Marie-Christine; Milon, Geneviève; Lang, Thierry

    2013-01-01

    After loading with live Leishmania (L) amazonensis amastigotes, mouse myeloid dendritic leucocytes/DLs are known to undergo reprogramming of their immune functions. In the study reported here, we investigated whether the presence of live L. amazonensis amastigotes in mouse bone marrow-derived DLs is able to trigger re-programming of DL lipid, and particularly neutral lipid metabolism. Affymetrix-based transcriptional profiles were determined in C57BL/6 and DBA/2 mouse bone marrow-derived DLs that had been sorted from cultures exposed or not to live L. amazonensis amastigotes. This showed that live amastigote-hosting DLs exhibited a coordinated increase in: (i) long-chain fatty acids (LCFA) and cholesterol uptake/transport, (ii) LCFA and cholesterol (re)-esterification to triacyl-sn-glycerol (TAG) and cholesteryl esters (CE), respectively. As these neutral lipids are known to make up the lipid body (LB) core, oleic acid was added to DL cultures and LB accumulation was compared in live amastigote-hosting versus amastigote-free DLs by epi-fluorescence and transmission electron microscopy. This showed that LBs were both significantly larger and more numerous in live amastigote-hosting mouse dendritic leucocytes. Moreover, many of the larger LB showed intimate contact with the membrane of the parasitophorous vacuoles hosting the live L. amazonensis amastigotes. As leucocyte LBs are known to be more than simple neutral lipid repositories, we set about addressing two related questions. Could LBs provide lipids to live amastigotes hosted within the DL parasitophorous vacuole and also deliver? Could LBs impact either directly or indirectly on the persistence of L. amazonensis amastigotes in rodent skin?

  1. Morphological properties of mouse retinal ganglion cells during postnatal development.

    PubMed

    Coombs, Julie L; Van Der List, Deborah; Chalupa, Leo M

    2007-08-20

    Quantitative methods were used to assess dendritic stratification and other structural features of developing mouse retinal ganglion cells from birth to after eye opening. Cells were labeled by transgenic expression of yellow fluorescent protein, DiOlistics or diffusion of DiI, and subsequently imaged in three dimensions on a confocal microscope followed by morphometric analysis of 13 different structural properties. At postnatal day 1 (P1), the dendrites of all cells ramified across the vertical extent of the inner plexiform layer (IPL). By P3/4, dendrites were largely confined to different strata of the IPL. The stratification of dendrites initially reflected a retraction of widely ramifying dendritic processes, but for the most part this was due to the subsequent vertical expansion of the IPL. By P8, distinct cell classes could be recognized, although these had not yet attained adult-like properties. The structural features differentiating cell classes were found to follow three different developmental trends. The mean values of one set of morphological parameters were essentially unchanged throughout postnatal development; another set of measures showed a rapid rise with age to adult values; and a third set of measures first increased with age and later decreased, with the regressive events initiated around the time of eye opening. These findings suggest that the morphological development of retinal ganglion cells is regulated by diverse factors operating during different but overlapping time periods. Our results also suggest that dendritic stratification may be more highly specified in the developing mammalian retina than has been previously realized.

  2. Development of Retinal Amacrine Cells and Their Dendritic Stratification

    PubMed Central

    Balasubramanian, Revathi

    2014-01-01

    Themammalian retina containsmultiple neurons, each of which contributes differentially to visual processing. Of these retinal neurons, amacrine cells have recently come to prime light since they facilitate majority of visual processing that takes place in the retina. Amacrine cells are also the most diverse group of neurons in the retina, classified majorly based on the neurotransmitter type they express and morphology of their dendritic arbors. Currently, little is known about the molecular basis contributing to this diversity during development. Amacrine cells also contribute to most of the synapses in the inner plexiform layer and mediate visual information input from bipolar cells onto retinal ganglion cells. In this review, we will describe the current understanding of amacrine cell and cell subtype development. Furthermore, we will address the molecular basis of retinal lamination at the inner plexiform layer. Overall, our review will provide a developmental perspective of amacrine cell subtype classification and their dendritic stratification. PMID:25170430

  3. Programmed Cell Death of Dendritic Cells in Immune Regulation

    PubMed Central

    Chen, Min; Wang, Jin

    2010-01-01

    Summary Programmed cell death is essential for the maintenance of lymphocyte homeostasis and immune tolerance. Dendritic cells (DCs), the most efficient antigen presenting cells, represent a small cell population in the immune system. However, DCs play major roles in the regulation of both innate and adaptive immune responses. Programmed cell death in DCs is essential for regulating DC homeostasis and consequently, the scope of immune responses. Interestingly, different DC subsets show varied turnover rates in vivo. The conventional DCs are relatively short-lived in most lymphoid organs, while plasmacytoid DCs are long-lived cells. Mitochondrion-dependent programmed cell death plays an important role in regulating spontaneous DC turnover. Antigen-specific T cells are also capable of killing DCs, thereby providing a mechanism for negative feedback regulation of immune responses. It has been shown that a surplus of DCs due to defects in programmed cell death leads to overactivation of lymphocytes and the onset of autoimmunity. Studying programmed cell death in DCs will shed light on the roles for DC turnover in the regulation of the duration and magnitude of immune responses in vivo, and in the maintenance of immune tolerance. PMID:20636805

  4. Lung dendritic cells facilitate extrapulmonary bacterial dissemination during pneumococcal pneumonia

    PubMed Central

    Rosendahl, Alva; Bergmann, Simone; Hammerschmidt, Sven; Goldmann, Oliver; Medina, Eva

    2013-01-01

    Streptococcus pneumoniae is a leading cause of bacterial pneumonia worldwide. Given the critical role of dendritic cells (DCs) in regulating and modulating the immune response to pathogens, we investigated here the role of DCs in S. pneumoniae lung infections. Using a well-established transgenic mouse line which allows the conditional transient depletion of DCs, we showed that ablation of DCs resulted in enhanced resistance to intranasal challenge with S. pneumoniae. DCs-depleted mice exhibited delayed bacterial systemic dissemination, significantly reduced bacterial loads in the infected organs and lower levels of serum inflammatory mediators than non-depleted animals. The increased resistance of DCs-depleted mice to S. pneumoniae was associated with a better capacity to restrict pneumococci extrapulmonary dissemination. Furthermore, we demonstrated that S. pneumoniae disseminated from the lungs into the regional lymph nodes in a cell-independent manner and that this direct way of dissemination was much more efficient in the presence of DCs. We also provide evidence that S. pneumoniae induces expression and activation of matrix metalloproteinase-9 (MMP-9) in cultured bone marrow-derived DCs. MMP-9 is a protease involved in the breakdown of extracellular matrix proteins and is critical for DC trafficking across extracellular matrix and basement membranes during the migration from the periphery to the lymph nodes. MMP-9 was also significantly up-regulated in the lungs of mice after intranasal infection with S. pneumoniae. Notably, the expression levels of MMP-9 in the infected lungs were significantly decreased after depletion of DCs suggesting the involvement of DCs in MMP-9 production during pneumococcal pneumonia. Thus, we propose that S. pneumoniae can exploit the DC-derived proteolysis to open tissue barriers thereby facilitating its own dissemination from the local site of infection. PMID:23802100

  5. Dendritic cell-derived nitric oxide inhibits the differentiation of effector dendritic cells

    PubMed Central

    Wu, Tianshu; Lu, Geming; Hu, Yuan; Zhang, Hui; Xu, Feihong; Wei, Peter; Chen, Kang; Tang, Hua; Yeretssian, Garabet; Xiong, Huabao

    2016-01-01

    Dendritic cells (DCs) play a pivotal role in the development of effective immune defense while avoiding detrimental inflammation and autoimmunity by regulating the balance of adaptive immunity and immune tolerance. However, the mechanisms that govern the effector and regulatory functions of DCs are incompletely understood. Here, we show that DC-derived nitric oxide (NO) controls the balance of effector and regulatory DC differentiation. Mice deficient in the NO-producing enzyme inducible nitric oxide synthase (iNOS) harbored increased effector DCs that produced interleukin-12, tumor necrosis factor (TNF) and IL-6 but normal numbers of regulatory DCs that expressed IL-10 and programmed cell death-1 (PD-1). Furthermore, an iNOS-specific inhibitor selectively enhanced effector DC differentiation, mimicking the effect of iNOS deficiency in mice. Conversely, an NO donor significantly suppressed effector DC development. Furthermore, iNOS−/− DCs supported enhanced T cell activation and proliferation. Finally iNOS−/− mice infected with the enteric pathogen Citrobacter rodentium suffered more severe intestinal inflammation with concomitant expansion of effector DCs in colon and spleen. Collectively, our results demonstrate that DC-derived iNOS restrains effector DC development, and offer the basis of therapeutic targeting of iNOS in DCs to treat autoimmune and inflammatory diseases. PMID:27556858

  6. Intravenous immunoglobulin ameliorates ITP via activating Fc gamma receptors on dendritic cells.

    PubMed

    Siragam, Vinayakumar; Crow, Andrew R; Brinc, Davor; Song, Seng; Freedman, John; Lazarus, Alan H

    2006-06-01

    Despite a more than 20-year experience of therapeutic benefit, the relevant molecular and cellular targets of intravenous immunoglobulin (IVIg) in autoimmune disease remain unclear. Contrary to the prevailing theories of IVIg action in autoimmunity, we show that IVIg drives signaling through activating Fc gamma receptors (Fc gammaR) in the amelioration of mouse immune thrombocytopenic purpura (ITP). The actual administration of IVIg was unnecessary because as few as 10(5) IVIg-treated cells could, upon adoptive transfer, ameliorate ITP. IVIg did not interact with the inhibitory Fc gammaRIIB on the initiator cell, although Fc gammaRIIB does have a role in the late phase of IVIg action. Notably, only IVIg-treated CD11c+ dendritic cells could mediate these effects. We hypothesize that IVIg forms soluble immune complexes in vivo that prime dendritic-cell regulatory activity. In conclusion, the clinical effects of IVIg in ameliorating ITP seem to involve the acute interaction of IVIg with activating Fc gammaR on dendritic cells.

  7. 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.

  8. Exopolysaccharide Produced by Lactobacillus Plantarum Induces Maturation of Dendritic Cells in BALB/c Mice.

    PubMed

    Tang, Yanjun; Dong, Wei; Wan, Keyu; Zhang, Ligang; Li, Chun; Zhang, Lili; Liu, Ning

    2015-01-01

    Lactobacillus plantarum (L. plantarum) exopolysaccharide (EPS) is an important bioactive component in fermented functional foods. However, there is a lack of data concerning the effects of L. plantarum EPS on maturation of mouse dendritic cells (DCs). In this study, we purified L. plantarum EPS and examined its effects on cytokines production by dendritic cells in serum and intestinal fluid of BALB/c mice, then investigated its effects on phenotypic and functional maturation of mouse bone marrow-derived dendritic cells (BMDCs). Cytokines (nitric oxide, IL-12p70, IL-10 and RANTES) in serum and intestinal fluid were analyzed by enzyme linked immunosorbent assay (ELISA) after the mice received EPS for 2, 5 and 7 days, respectively. DCs derived from bone marrow of BALB/c mouse were treated with EPS, then the phenotypic maturation of BMDCs was analyzed using flow cytometer and the functional maturation of BMDCs was analyzed by ELISA, and, lastly, mixed lymphocyte proliferation was performed. We found the molecular weight of purified EPS was approximately 2.4×106 Da and it was composed of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in a molar ratio of 2:1:1:10:4:205:215. We observed that L. plantarum EPS enriched production of nitric oxide, IL-12p70 and RANTES, and decreased the secretion of IL-10 in the serum or intestinal fluid as well as in the supernatant of DCs treated with the EPS. The EPS also up-regulated the expression of MHC II and CD86 on DCs surface and promoted T cells to proliferate in vitro. Our data provide direct evidence to suggest that L. plantarum EPS can effectively induce maturation of DCs in mice.

  9. Ceramide Inhibits Antigen Uptake and Presentation by Dendritic Cells

    PubMed Central

    Sallusto, Federica; Nicolò, Chiara; De Maria, Ruggero; Corinti, Silvia; Testi, Roberto

    1996-01-01

    Ceramides are intramembrane diffusible mediators involved in transducing signals originated from a variety of cell surface receptors. Different adaptive and differentiative cellular responses, including apoptotic cell death, use ceramide-mediated pathways as an essential part of the program. Here, we show that human dendritic cells respond to CD40 ligand, as well as to tumor necrosis factor-α and IL-1β, with intracellular ceramide accumulation, as they are induced to differentiate. Dendritic cells down-modulate their capacity to take up soluble antigens in response to exogenously added or endogenously produced ceramides. This is followed by an impairment in presenting soluble antigens to specific T cell clones, while cell viability and the capacity to stimulate allogeneic responses or to present immunogenic peptides is fully preserved. Thus, ceramide-mediated pathways initiated by different cytokines can actively modulate professional antigen-presenting cell function and antigen-specific immune responses. PMID:8976196

  10. GSK-3β Overexpression Alters the Dendritic Spines of Developmentally Generated Granule Neurons in the Mouse Hippocampal Dentate Gyrus

    PubMed Central

    Pallas-Bazarra, Noemí; Kastanauskaite, Asta; Avila, Jesús; DeFelipe, Javier; Llorens-Martín, María

    2017-01-01

    The dentate gyrus (DG) plays a crucial role in hippocampal-related memory. The most abundant cellular type in the DG, namely granule neurons, are developmentally generated around postnatal day P6 in mice. Moreover, a unique feature of the DG is the occurrence of adult hippocampal neurogenesis, a process that gives rise to newborn granule neurons throughout life. Adult-born and developmentally generated granule neurons share some maturational aspects but differ in others, such as in their positioning within the granule cell layer. Adult hippocampal neurogenesis encompasses a series of plastic changes that modify the function of the hippocampal trisynaptic network. In this regard, it is known that glycogen synthase kinase 3β (GSK-3β) regulates both synaptic plasticity and memory. By using a transgenic mouse overexpressing GSK-3β in hippocampal neurons, we previously demonstrated that the overexpression of this kinase has deleterious effects on the maturation of newborn granule neurons. In the present study, we addressed the effects of GSK-3β overexpression on the morphology and number of dendritic spines of developmentally generated granule neurons. To this end, we performed intracellular injections of Lucifer Yellow in developmentally generated granule neurons of wild-type and GSK-3β-overexpressing mice and analyzed the number and morphologies of dendritic spines (namely, stubby, thin and mushroom). GSK-3β overexpression led to a general reduction in the number of dendritic spines. In addition, it caused a slight reduction in the percentage, head diameter and length of thin spines, whereas the head diameter of mushroom spines was increased. PMID:28344548

  11. Dendritic Spine Loss and Chronic White Matter Inflammation in a Mouse Model of Highly Repetitive Head Trauma

    PubMed Central

    Winston, Charisse N.; Noël, Anastasia; Neustadtl, Aidan; Parsadanian, Maia; Barton, David J.; Chellappa, Deepa; Wilkins, Tiffany E.; Alikhani, Andrew D.; Zapple, David N.; Villapol, Sonia; Planel, Emmanuel; Burns, Mark P.

    2017-01-01

    Mild traumatic brain injury (mTBI) is an emerging risk for chronic behavioral, cognitive, and neurodegenerative conditions. Athletes absorb several hundred mTBIs each year; however, rodent models of repeat mTBI (rmTBI) are often limited to impacts in the single digits. Herein, we describe the effects of 30 rmTBIs, examining structural and pathological changes in mice up to 365 days after injury. We found that single mTBI causes a brief loss of consciousness and a transient reduction in dendritic spines, reflecting a loss of excitatory synapses. Single mTBI does not cause axonal injury, neuroinflammation, or cell death in the gray or white matter. Thirty rmTBIs with a 1-day interval between each mTBI do not cause dendritic spine loss; however, when the interinjury interval is increased to 7 days, dendritic spine loss is reinstated. Thirty rmTBIs cause white matter pathology characterized by positive silver and Fluoro-Jade B staining, and microglial proliferation and activation. This pathology continues to develop through 60 days, and is still apparent at 365 days, after injury. However, rmTBIs did not increase β-amyloid levels or tau phosphorylation in the 3xTg-AD mouse model of Alzheimer disease. Our data reveal that single mTBI causes a transient loss of synapses, but that rmTBIs habituate to repetitive injury within a short time period. rmTBI causes the development of progressive white matter pathology that continues for months after the final impact. PMID:26857506

  12. Dendritic Spine Loss and Chronic White Matter Inflammation in a Mouse Model of Highly Repetitive Head Trauma.

    PubMed

    Winston, Charisse N; Noël, Anastasia; Neustadtl, Aidan; Parsadanian, Maia; Barton, David J; Chellappa, Deepa; Wilkins, Tiffany E; Alikhani, Andrew D; Zapple, David N; Villapol, Sonia; Planel, Emmanuel; Burns, Mark P

    2016-03-01

    Mild traumatic brain injury (mTBI) is an emerging risk for chronic behavioral, cognitive, and neurodegenerative conditions. Athletes absorb several hundred mTBIs each year; however, rodent models of repeat mTBI (rmTBI) are often limited to impacts in the single digits. Herein, we describe the effects of 30 rmTBIs, examining structural and pathological changes in mice up to 365 days after injury. We found that single mTBI causes a brief loss of consciousness and a transient reduction in dendritic spines, reflecting a loss of excitatory synapses. Single mTBI does not cause axonal injury, neuroinflammation, or cell death in the gray or white matter. Thirty rmTBIs with a 1-day interval between each mTBI do not cause dendritic spine loss; however, when the interinjury interval is increased to 7 days, dendritic spine loss is reinstated. Thirty rmTBIs cause white matter pathology characterized by positive silver and Fluoro-Jade B staining, and microglial proliferation and activation. This pathology continues to develop through 60 days, and is still apparent at 365 days, after injury. However, rmTBIs did not increase β-amyloid levels or tau phosphorylation in the 3xTg-AD mouse model of Alzheimer disease. Our data reveal that single mTBI causes a transient loss of synapses, but that rmTBIs habituate to repetitive injury within a short time period. rmTBI causes the development of progressive white matter pathology that continues for months after the final impact. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  13. SH2 domain–containing adaptor protein B expressed in dendritic cells is involved in T-cell homeostasis by regulating dendritic cell–mediated Th2 immunity

    PubMed Central

    2017-01-01

    Purpose The Src homology 2 domain–containing adaptor protein B (SHB) is widely expressed in immune cells and acts as an important regulator for hematopoietic cell function. SHB silencing induces Th2 immunity in mice. SHB is also involved in T-cell homeostasis in vivo. However, SHB has not yet been studied and addressed in association with dendritic cells (DCs). Materials and Methods The effects of SHB expression on the immunogenicity of DCs were assessed by Shb gene silencing in mouse bone marrow–derived DCs (BMDCs). After silencing, surface phenotype, cytokine expression profile, and T-cell stimulation capacity of BMDCs were examined. We investigated the signaling pathways involved in SHB expression during BMDC development. We also examined the immunogenicity of SHB-knockdown (SHBKD) BMDCs in a mouse atopic dermatitis model. Results SHB was steadily expressed in mouse splenic DCs and in in vitro–generated BMDCs in both immature and mature stages. SHB expression was contingent on activation of the mitogen- activated protein kinase/Foxa2 signaling pathway during DC development. SHBKD increased the expression of MHC class II and costimulatory molecules without affecting the cytokine expression of BMDCs. When co-cultured with T cells, SHBKD in BMDCs significantly induced CD4+ T-cell proliferation and the expression of Th2 cytokines, while the regulatory T cell (Treg) population was downregulated. In mouse atopic dermatitis model, mice inoculated with SHBKD DCs developed more severe symptoms of atopic dermatitis compared with mice injected with control DCs. Conclusion SHB expression in DCs plays an important role in T-cell homeostasis in vivo by regulating DC-mediated Th2 polarization. PMID:28168174

  14. Epidermal Viral Immunity Induced by CD8α+ Dendritic Cells But Not by Langerhans Cells

    NASA Astrophysics Data System (ADS)

    Allan, Rhys S.; Smith, Chris M.; Belz, Gabrielle T.; van Lint, Allison L.; Wakim, Linda M.; Heath, William R.; Carbone, Francis R.

    2003-09-01

    The classical paradigm for dendritic cell function derives from the study of Langerhans cells, which predominate within skin epidermis. After an encounter with foreign agents, Langerhans cells are thought to migrate to draining lymph nodes, where they initiate T cell priming. Contrary to this, we show here that infection of murine epidermis by herpes simplex virus did not result in the priming of virus-specific cytotoxic T lymphocytes by Langerhans cells. Rather, the priming response required a distinct CD8α+ dendritic cell subset. Thus, the traditional view of Langerhans cells in epidermal immunity needs to be revisited to accommodate a requirement for other dendritic cells in this response.

  15. Dendritic cells induce Tc1 cell differentiation via the CD40/CD40L pathway in mice after exposure to cigarette smoke.

    PubMed

    Kuang, Liang-Jian; Deng, Ting-Ting; Wang, Qin; Qiu, Shi-Lin; Liang, Yi; He, Zhi-Yi; Zhang, Jian-Quan; Bai, Jing; Li, Mei-Hua; Deng, Jing-Min; Liu, Guang-Nan; Liu, Ji-Feng; Zhong, Xiao-Ning

    2016-09-01

    Dendritic cells and CD8(+) T cells participate in the pathology of chronic obstructive pulmonary disease, including emphysema, but little is known of the involvement of the CD40/CD40L pathway. We investigated the role of the CD40/CD40L pathway in Tc1 cell differentiation induced by dendritic cells in a mouse model of emphysema, and in vitro. C57BL/6J wild-type and CD40(-/-) mice were exposed to cigarette smoke (CS) or not (control), for 24 wk. In vitro experiments involved wild-type and CD40(-/-) dendritic cells treated with CS extract (CSE) or not. Compared with the control groups, the CS mice (both wild type and CD40(-/-)) had a greater percentage of lung dendritic cells and higher levels of major histocompatability complex (MHC) class I molecules and costimulatory molecules CD40 and CD80. Relative to the CS CD40(-/-) mice, the CS wild type showed greater signs of lung damage and Tc1 cell differentiation. In vitro, the CSE-treated wild-type cells evidenced more cytokine release (IL-12/p70) and Tc1 cell differentiation than did the CSE-treated CD40(-/-) cells. Exposure to cigarette smoke increases the percentage of lung dendritic cells and promotes Tc1 cell differentiation via the CD40/CD40L pathway. Blocking the CD40/CD40L pathway may suppress development of emphysema in mice exposed to cigarette smoke. Copyright © 2016 the American Physiological Society.

  16. Aire-Overexpressing Dendritic Cells Induce Peripheral CD4⁺ T Cell Tolerance.

    PubMed

    Li, Dongbei; Li, Haijun; Fu, Haiying; Niu, Kunwei; Guo, Yantong; Guo, Chuan; Sun, Jitong; Li, Yi; Yang, Wei

    2015-12-29

    Autoimmune regulator (Aire) can promote the ectopic expression of peripheral tissue-restricted antigens (TRAs) in thymic medullary epithelial cells (mTECs), which leads to the deletion of autoreactive T cells and consequently prevents autoimmune diseases. However, the functions of Aire in the periphery, such as in dendritic cells (DCs), remain unclear. This study's aim was to investigate the effect of Aire-overexpressing DCs (Aire cells) on the functions of CD4⁺ T cells and the treatment of type 1 diabetes (T1D). We demonstrated that Aire cells upregulated the mRNA levels of the tolerance-related molecules CD73, Lag3, and FR4 and the apoptosis of CD4⁺ T cells in STZ-T1D mouse-derived splenocytes. Furthermore, following insulin stimulation, Aire cells decreased the number of CD4⁺ IFN-γ⁺ T cells in both STZ-T1D and WT mouse-derived splenocytes and reduced the expression levels of TCR signaling molecules (Ca(2+) and p-ERK) in CD4⁺ T cells. We observed that Aire cells-induced CD4⁺ T cells could delay the development of T1D. In summary, Aire-expressing DCs inhibited TCR signaling pathways and decreased the quantity of CD4⁺IFN-γ⁺ autoreactive T cells. These data suggest a mechanism for Aire in the maintenance of peripheral immune tolerance and provide a potential method to control autoimmunity by targeting Aire.

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

    NASA Astrophysics Data System (ADS)

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

    2016-11-01

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

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

    PubMed Central

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

    2016-01-01

    Slowing down or even stopping light is the first task to realising optical information transmission and storage. Theoretical studies have revealed that metamaterials can slow down or even stop light; however, the difficulty of preparing metamaterials that operate in visible light hinders progress in the research of slowing or stopping light. Metasurfaces provide a new opportunity to make progress in such research. In this paper, we propose a dendritic cell cluster metasurface consisting of dendritic structures. The simulation results show that dendritic structure can realise abnormal reflection and refraction effects. Single- and double-layer dendritic metasurfaces that respond in visible light were prepared by electrochemical deposition. Abnormal Goos-Hänchen (GH) shifts were experimentally obtained. The rainbow trapping effect was observed in a waveguide constructed using the dendritic metasurface sample. The incident white light was separated into seven colours ranging from blue to red light. The measured transmission energy in the waveguide showed that the energy escaping from the waveguide was zero at the resonant frequency of the sample under a certain amount of incident light. The proposed metasurface has a simple preparation process, functions in visible light, and can be readily extended to the infrared band and communication wavelengths. PMID:27886279

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

    PubMed

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

    2016-11-25

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

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

    PubMed

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

    2008-03-01

    Dendritic cells (DCs) are considered critical for the induction of graft-versus-host disease (GVHD) after bone marrow transplantation (BMT). In addition to their priming function, dendritic cells have been shown to induce organ-tropism through induction of specific homing molecules on T cells. Using adoptive transfer of CFSE-labeled cells, we first demonstrated that alloreactive T cells differentially up-regulate specific homing molecules in vivo. Host-type dendritic cells from the GVHD target organs liver and spleen or skin- and gut-draining lymph nodes effectively primed naive allogeneic T cells in vitro with the exception of liver-derived dendritic cells, which showed less stimulatory capacity. Gut-derived dendritic cells induced alloreactive donor T cells with a gut-homing phenotype that caused increased GVHD mortality and morbidity compared with T cells stimulated with dendritic cells from spleen, liver, and peripheral lymph nodes in an MHC-mismatched murine BMT model. However, in vivo analysis demonstrated that the in vitro imprinting of homing molecules on alloreactive T cells was only transient. In conclusion, organ-derived dendritic cells can efficiently induce specific homing molecules on alloreactive T cells. A gut-homing phenotype correlates with increased GVHD mortality and morbidity after murine BMT, underlining the importance of the gut in the pathophysiology of GVHD.

  1. Optimization of multi-epitopic HIV-1 recombinant protein expression in prokaryote system and conjugation to mouse DEC-205 monoclonal antibody: implication for in-vivo targeted delivery of dendritic cells

    PubMed Central

    Rahimi, Roghayeh; Ebtekar, Massoumeh; Moazzeni, Seyed Mohammad; Mostafaie, Ali; Mahdavi, Mehdi

    2015-01-01

    Objective(s): Multi-epitopic protein vaccines and direction of vaccine delivery to dendritic cells (DCs) are promising approaches for enhancing immune responses against mutable pathogens. Escherichia coli is current host for expression of recombinant proteins, and it is important to optimize expression condition. The aim of this study was the optimization of multi-epitopic HIV-1 tat/pol/gag/env recombinant protein (HIVtop4) expression by E. coli and conjugation of purified protein to anti DEC-205 monoclonal antibody as candidate vaccine. Materials and Methods: In this study, expression was induced in BL21 (DE3) E. coli cells by optimization of induction condition, post induction incubation time, temperature and culture medium formula. Some culture mediums were used for cell culture, and isopropyl-beta-D-thiogalactopyranoside was used for induction of expression. Protein was purified by Ni-NTA column chromatography and confirmed against anti-His antibody in western-blotting. To exploit DCs properties for immunization purposes, recombinant protein chemically coupled to αDEC-205 monoclonal antibody and confirmed against anti-His antibody in western-blotting. Results: The optimum condition for expression was 1 mM IPTG during 4 hr cultures in 2XYT medium, and final protein produced in soluble form. Conjugation of purified protein to αDEC-205 antibody resulted in smears of protein: antibodies conjugate in different molecular weights. Conclusion: The best cultivation condition for production of HIVtop4 protein is induction by 1 mM IPTG during 4 hr in 2XYT medium. The final concentration of purified protein was 500 µg/ml. PMID:25810888

  2. Optimization of multi-epitopic HIV-1 recombinant protein expression in prokaryote system and conjugation to mouse DEC-205 monoclonal antibody: implication for in-vivo targeted delivery of dendritic cells.

    PubMed

    Rahimi, Roghayeh; Ebtekar, Massoumeh; Moazzeni, Seyed Mohammad; Mostafaie, Ali; Mahdavi, Mehdi

    2015-02-01

    Multi-epitopic protein vaccines and direction of vaccine delivery to dendritic cells (DCs) are promising approaches for enhancing immune responses against mutable pathogens. Escherichia coli is current host for expression of recombinant proteins, and it is important to optimize expression condition. The aim of this study was the optimization of multi-epitopic HIV-1 tat/pol/gag/env recombinant protein (HIVtop4) expression by E. coli and conjugation of purified protein to anti DEC-205 monoclonal antibody as candidate vaccine. In this study, expression was induced in BL21 (DE3) E. coli cells by optimization of induction condition, post induction incubation time, temperature and culture medium formula. Some culture mediums were used for cell culture, and isopropyl-beta-D-thiogalactopyranoside was used for induction of expression. Protein was purified by Ni-NTA column chromatography and confirmed against anti-His antibody in western-blotting. To exploit DCs properties for immunization purposes, recombinant protein chemically coupled to αDEC-205 monoclonal antibody and confirmed against anti-His antibody in western-blotting. The optimum condition for expression was 1 mM IPTG during 4 hr cultures in 2XYT medium, and final protein produced in soluble form. Conjugation of purified protein to αDEC-205 antibody resulted in smears of protein: antibodies conjugate in different molecular weights. The best cultivation condition for production of HIVtop4 protein is induction by 1 mM IPTG during 4 hr in 2XYT medium. The final concentration of purified protein was 500 µg/ml.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  4. Cell type-specific bipolar cell input to ganglion cells in the mouse retina.

    PubMed

    Neumann, S; Hüser, L; Ondreka, K; Auler, N; Haverkamp, S

    2016-03-01

    Many distinct ganglion cell types, which are the output elements of the retina, were found to encode for specific features of a visual scene such as contrast, color information or movement. The detailed composition of retinal circuits leading to this tuning of retinal ganglion cells, however, is apart from some prominent examples, largely unknown. Here we aimed to investigate if ganglion cell types in the mouse retina receive selective input from specific bipolar cell types or if they sample their synaptic input non-selectively from all bipolar cell types stratifying within their dendritic tree. To address this question we took an anatomical approach and immunolabeled retinae of two transgenic mouse lines (GFP-O and JAM-B) with markers for ribbon synapses and type 2 bipolar cells. We morphologically identified all green fluorescent protein (GFP)-expressing ganglion cell types, which co-stratified with type 2 bipolar cells and assessed the total number of bipolar input synapses and the proportion of synapses deriving from type 2 bipolar cells. Only JAM-B ganglion cells received synaptic input preferentially from bipolar cell types other than type 2 bipolar cells whereas the other analyzed ganglion cell types sampled their bipolar input most likely from all bipolar cell terminals within their dendritic arbor. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Isolation and characterization of dendritic cells from adenoids of children with otitis media with effusion.

    PubMed Central

    van Nieuwkerk, E B; van der Baan, S; Richters, C D; Kamperdijk, E W

    1992-01-01

    Dendritic cells were enriched from adenoids of children with otitis media with effusion (OME) by density gradient centrifugation and culture techniques. An enrichment of 40-140-fold was obtained for dendritic cells. These cells were identified using morphology, enzyme cytochemistry, immunocytochemistry and functional criteria. Dendritic cells could be easily distinguished from macrophages. It appeared that the MoAb EBM11 (CD68) discriminated between dendritic cells and macrophages; in dendritic cells this activity was localized in a spot, whereas in macrophages it was found throughout the whole cytoplasm. The fractions enriched with dendritic cells showed a strong stimulatory effect on allogeneic T cells. These responses were MHC class II dependent since they could be blocked by anti-HLA-DR/DQ MoAbs. The data clearly show that dendritic cells from adenoids of children with OME still have functional capacities. Images Fig. 1 Fig. 2 Fig. 3 PMID:1572100

  6. Natural amines inhibit activation of human plasmacytoid dendritic cells through CXCR4 engagement

    PubMed Central

    Smith, Nikaïa; Pietrancosta, Nicolas; Davidson, Sophia; Dutrieux, Jacques; Chauveau, Lise; Cutolo, Pasquale; Dy, Michel; Scott-Algara, Daniel; Manoury, Bénédicte; Zirafi, Onofrio; McCort-Tranchepain, Isabelle; Durroux, Thierry; Bachelerie, Françoise; Schwartz, Olivier; Münch, Jan; Wack, Andreas; Nisole, Sébastien; Herbeuval, Jean-Philippe

    2017-01-01

    Plasmacytoid dendritic cells (pDC) are specialized in secretion of type I interferon in response to pathogens. Here we show that natural monoamines and synthetic amines inhibit pDC activation by RNA viruses. Furthermore, a synthetic analogue of histamine reduces type I interferon production in a mouse model of influenza infection. We identify CXC chemokine receptor 4 (CXCR4) as a receptor used by amines to inhibit pDC. Our study establishes a functional link between natural amines and the innate immune system and identifies CXCR4 as a potential ‘on-off' switch of pDC activity with therapeutic potential. PMID:28181493

  7. Dendritic Cells and HIV-1 Trans-Infection

    PubMed Central

    McDonald, David

    2010-01-01

    Dendritic cells initiate and sustain immune responses by migrating to sites of pathogenic insult, transporting antigens to lymphoid tissues and signaling immune specific activation of T cells through the formation of the immunological synapse. Dendritic cells can also transfer intact, infectious HIV-1 to CD4 T cells through an analogous structure, the infectious synapse. This replication independent mode of HIV-1 transmission, known as trans-infection, greatly increases T cell infection in vitro and is thought to contribute to viral dissemination in vivo. This review outlines the recent data defining the mechanisms of trans-infection and provides a context for the potential contribution of trans-infection in HIV-1 disease. PMID:21994702

  8. Immune heterogeneity in neuroinflammation: dendritic cells in the brain.

    PubMed

    Colton, Carol A

    2013-03-01

    Dendritic cells (DC) are critical to an integrated immune response and serve as the key link between the innate and adaptive arms of the immune system. Under steady state conditions, brain DC's act as sentinels, continually sampling their local environment. They share this function with macrophages derived from the same basic hemopoietic (bone marrow-derived) precursor and with parenchymal microglia that arise from a unique non-hemopoietic origin. While multiple cells may serve as antigen presenting cells (APCs), dendritic cells present both foreign and self-proteins to naïve T cells that, in turn, carry out effector functions that serve to protect or destroy. The resulting activation of the adaptive response is a critical step to resolution of injury or infection and is key to survival. In this review we will explore the critical roles that DCs play in the brain's response to neuroinflammatory disease with emphasis on how the brain's microenvironment impacts these actions.

  9. How tolerogenic dendritic cells induce regulatory T cells

    PubMed Central

    Maldonado, Roberto A.; von Andrian, Ulrich H.

    2010-01-01

    Since their discovery by Steinman and Cohn in 1973, dendritic cells (DCs) have become increasingly recognized for their crucial role as regulators of innate and adaptive immunity. DCs are exquisitely adept at acquiring, processing and presenting antigens to T cells. They also adjust the context (and hence the outcome) of antigen presentation in response to a plethora of environmental inputs that signal the occurence of pathogens or tissue damage. Such signals generally boost DC maturation, which promotes their migration from peripheral tissues into and within secondary lymphoid organs and their capacity to induce and regulate effector T cell responses. Conversely, more recent observations indicate that DCs are also crucial to ensure immunological peace. Indeed, DCs constantly present innocuous self and non-self antigens in a fashion that promotes tolerance, at least in part, through the control of regulatory T cells (Tregs). Tregs are specialized T cells that exert their immuno-suppressive function through a variety of mechanisms affecting both DCs and effector cells. Here, we review recent advances in our understanding of the relationship between tolerogenic DCs and Tregs. PMID:21056730

  10. Censoring of self-reactive B cells by follicular dendritic cell-displayed self-antigen.

    PubMed

    Yau, Irene W; Cato, Matthew H; Jellusova, Julia; Hurtado de Mendoza, Tatiana; Brink, Robert; Rickert, Robert C

    2013-08-01

    In the secondary lymphoid organs, intimate contact with follicular dendritic cells (FDCs) is required for B cell retention and Ag-driven selection during the germinal center response. However, selection of self-reactive B cells by Ag on FDCs has not been addressed. To this end, we generated a mouse model to conditionally express a membrane-bound self-antigen on FDCs and to monitor the fate of developing self-reactive B cells. In this article, we show that self-antigen displayed on FDCs mediates effective elimination of self-reactive B cells at the transitional stage. Notwithstanding, some self-reactive B cells persist beyond this checkpoint, showing evidence of Ag experience and intact proximal BCR signaling, but they are short-lived and unable to elicit T cell help. These results implicate FDCs as an important component of peripheral B cell tolerance that prevents the emergence of naive B cells capable of responding to sequestered self-antigens.

  11. A Comparison between Growth Morphology of "Eutectic" Cells/Dendrites and Single-Phase Cells/Dendrites

    NASA Technical Reports Server (NTRS)

    Tewari, S. N.; Raj, S. V.; Locci, I. E.

    2003-01-01

    Directionally solidified (DS) intermetallic and ceramic-based eutectic alloys with an in-situ composite microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve heir high-temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic "colonies." Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability analysis of Mullins and Sekerka has been extended to describe their formation. Onset of their formation shows a good agreement with this approach; however, unlike the single-phase cells and dendrites, there is limited examination of their growth speed dependence of spacing, morphology, and spatial distribution. The purpose of this study is to compare the growth speed dependence of the morphology, spacing, and spatial distribution of eutectic cells and dendrites with that for the single-phase cells and dendrites.

  12. Phenotype and function of CD209+ bovine blood dendritic cells, monocyte-derived-dendritic cells and monocyte-derived macrophages

    USDA-ARS?s Scientific Manuscript database

    Phylogenic comparisons of the mononuclear phagocyte system (MPS) of humans and mice demonstrate phenotypic divergence of dendritic cell (DC) subsets that play similar roles in innate and adaptive immunity. Although differing in phenotype, DC can be classified into four groups according to ontogeny a...

  13. Kv1 channels selectively prevent dendritic hyperexcitability in rat Purkinje cells

    PubMed Central

    Khavandgar, Simin; Walter, Joy T; Sageser, Kristin; Khodakhah, Kamran

    2005-01-01

    Purkinje cells, the sole output of the cerebellar cortex, encode the timing signals required for motor coordination in their firing rate and activity pattern. Dendrites of Purkinje cells express a high density of P/Q-type voltage-gated calcium channels and fire dendritic calcium spikes. Here we show that dendritic subthreshold Kv1.2 subunit-containing Kv1 potassium channels prevent generation of random spontaneous calcium spikes. With Kv1 channels blocked, dendritic calcium spikes drive bursts of somatic sodium spikes and prevent the cell from faithfully encoding motor timing signals. The selective dendritic function of Kv1 channels in Purkinje cells allows them to effectively suppress dendritic hyperexcitability without hindering the generation of somatic action potentials. Further, we show that Kv1 channels also contribute to dendritic integration of parallel fibre synaptic input. Kv1 channels are often targeted to soma and axon and the data presented support a major dendritic function for these channels. PMID:16210348

  14. Abnormal dendrite and spine morphology in primary visual cortex in the CGG knock-in mouse model of the fragile X premutation.

    PubMed

    Berman, Robert F; Murray, Karl D; Arque, Gloria; Hunsaker, Michael R; Wenzel, H Jürgen

    2012-06-01

    The fragile X mental retardation 1 gene (Fmr1) is polymorphic for CGG trinucleotide repeat number in the 5'-untranslated region, with repeat lengths <45 associated with typical development and repeat lengths >200 resulting in hypermethylation and transcriptional silencing of the gene and mental retardation in the fragile X Syndrome (FXS). Individuals with CGG repeat expansions between 55 and 200 are carriers of the fragile X premutation (PM). PM carriers show a phenotype that can include anxiety, depression, social phobia, and memory deficits. They are also at risk for developing fragile X-associated tremor/ataxia syndrome (FXTAS), a late onset neurodegenerative disorder characterized by tremor, ataxia, cognitive impairment, and neuropathologic features including intranuclear inclusions in neurons and astrocytes, loss of Purkinje cells, and white matter disease. However, very little is known about dendritic morphology in PM or in FXTAS. Therefore, we carried out a Golgi study of dendritic complexity and dendritic spine morphology in layer II/III pyramidal neurons in primary visual cortex in a knock-in (KI) mouse model of the PM. These CGG KI mice carry an expanded CGG trinucleotide repeat on Fmr1, and model many features of the PM and FXTAS. Compared to wild-type (WT) mice, CGG KI mice showed fewer dendritic branches proximal to the soma, reduced total dendritic length, and a higher frequency of longer dendritic spines. The distribution of morphologic spine types (e.g., stubby, mushroom, filopodial) did not differ between WT and KI mice. These findings demonstrate that synaptic circuitry is abnormal in visual cortex of mice used to model the PM, and suggest that such changes may underlie neurologic features found in individuals carrying the PM as well as in individuals with FXTAS. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

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

    PubMed

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

    2010-06-01

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

  16. 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

  17. Monocyte-derived dendritic cells from horses differ from dendritic cells of humans and mice

    PubMed Central

    Mauel, Susanne; Steinbach, Falko; Ludwig, Hanns

    2006-01-01

    Dendritic cells (DC) are the initiators of immune responses and are present in most tissues in vivo. To generate myeloid DC from monocytes (MoDC) in vitro the necessary cytokines are granulocyte–macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). Using degenerated primers delineated from other species and rapid amplification of cDNA ends reverse transcription–polymerase chain reaction (RACE RT-PCR), the cDNA of equine (eq.) GM-CSF was cloned and found to have a point deletion at the 3′-end of eq.GM-CSF, resulting in a 24-nucleotide extended open reading frame not described in any species thus far. For differentiating eq.MoDC, monocytes were stimulated with eq.GM-CSF and eq.IL-4. The eq.MoDC was analysed by both light and electron microscopy and by flow cytometry and mixed lymphocyte reaction. The eq.MoDC obtained had the typical morphology and function of DC, including the ability to stimulate allogeneic T cells in a mixed lymphocyte reaction. In contrast to the human system, however, monocytes had to be differentiated for 6–7 days before immature DC were obtained. Our data also indicate that lipopolysaccharide or poly(I:C) alone are not sufficient to confer the full phenotypic transition into mature DC. Thus our study contributes to understanding the heterogeneity of immunity and adds important information on the equine immune system, which is clearly distinct from those of mice or man. PMID:16556260

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

    PubMed

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

    2015-01-15

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

  19. Chronic Social Defeat Stress Modulates Dendritic Spines Structural Plasticity in Adult Mouse Frontal Association Cortex

    PubMed Central

    Shu, Yu

    2017-01-01

    Chronic stress is associated with occurrence of many mental disorders. Previous studies have shown that dendrites and spines of pyramidal neurons of the prefrontal cortex undergo drastic reorganization following chronic stress experience. So the prefrontal cortex is believed to play a key role in response of neural system to chronic stress. However, how stress induces dynamic structural changes in neural circuit of prefrontal cortex remains unknown. In the present study, we examined the effects of chronic social defeat stress on dendritic spine structural plasticity in the mouse frontal association (FrA) cortex in vivo using two-photon microscopy. We found that chronic stress altered spine dynamics in FrA and increased the connectivity in FrA neural circuits. We also found that the changes in spine dynamics in FrA are correlated with the deficit of sucrose preference in defeated mice. Our findings suggest that chronic stress experience leads to adaptive change in neural circuits that may be important for encoding stress experience related memory and anhedonia. PMID:28197343

  20. Docosahexaenoic Acid Protects from Dendritic Pathology in an Alzheimer’s Disease Mouse Model

    PubMed Central

    Calon, Frédéric; Lim, Giselle P.; Yang, Fusheng; Morihara, Takashi; Teter, Bruce; Ubeda, Oliver; Rostaing, Phillippe; Triller, Antoine; Salem, Norman; Ashe, Karen H.; Frautschy, Sally A.; Cole, Greg M.

    2005-01-01

    Learning and memory depend on dendritic spine actin assembly and docosahexaenoic acid (DHA), an essential n-3 (omega-3) polyunsaturated fatty acid (PFA). High DHA consumption is associated with reduced Alzheimer’s disease (AD) risk, yet mechanisms and therapeutic potential remain elusive. Here, we report that reduction of dietary n-3 PFA in an AD mouse model resulted in 80%–90% losses of the p85α subunit of phosphatidylinositol 3-kinase and the postsynaptic actin-regulating protein drebrin, as in AD brain. The loss of postsynaptic proteins was associated with increased oxidation, without concomitant neuron or pre-synaptic protein loss. N-3 PFA depletion increased caspase-cleaved actin, which was localized in dendrites ultrastructurally. Treatment of n-3 PFA-restricted mice with DHA protected against these effects and behavioral deficits and increased antiapoptotic BAD phosphorylation. Since n-3 PFAs are essential for p85-mediated CNS insulin signaling and selective protection of postsynaptic proteins, these findings have implications for neurodegenerative diseases where synaptic loss is critical, especially AD. PMID:15339646

  1. Splenic Inflammatory Pseudotumor-Like Follicular Dendritic Cell Tumor

    PubMed Central

    Vardas, Konstantinos; Manganas, Dimitrios; Papadimitriou, Georgios; Kalatzis, Vasileios; Kyriakopoulos, Georgios; Chantziara, Maria; Exarhos, Dimitrios; Drakopoulos, Spiros

    2014-01-01

    Inflammatory pseudotumor of the spleen with expression of follicular dendritic cell markers is an extremely rare lesion with only a few cases reported previously. The present study reports on an inflammatory pseudotumor of the spleen 10 × 8 × 7 cm in size that was incidentally found in a 61-year-old man and increased gradually in size during a period of 3 months. Abdominal ultrasonography revealed a well-circumscribed splenic mass, and abdominal computed tomography confirmed the presence of a well-circumscribed isodense lesion in the splenic hilum with inhomogenous enhancement in the early-phase images and no enhancement on delayed-phase contrast-enhanced images. Magnetic resonance imaging of the abdomen showed a well-defined isodense tumor on T1-weighted images with mildly increased signal intensity on T2-weighted images, and this is only the second study that provides MRI findings of this entity. The patient underwent an uncomplicated open splenectomy for definitive histologic diagnosis. Under microscopic examination, the lesion was an admixture of lymphocytes, plasma cells and spindle cells. In situ hybridization analysis for Epstein-Barr virus (EBV) revealed that most of the spindle cells were positive for EBV, and immunochemistry showed the expression of the follicular dendritic cell markers CD21, CD35 and CD23 within the tumor. The diagnosis of inflammatory pseudotumor-like follicular dendritic cell tumor was established. PMID:25076893

  2. Manipulation of Mouse Embryonic Stem Cells for Knockout Mouse Production

    PubMed Central

    Limaye, Advait; Hall, Bradford; Kulkarni, Ashok B

    2009-01-01

    The establishment of mouse embryonic stem (ES) cell liness has allowed for the generation of the knockout mouse. ES cells that are genetically altered in culture can then be manipulated to derive a whole mouse containing the desired mutation. To successfully generate a knockout mouse, however, the ES cells must be carefully cultivated in a pluripotent state throughout the gene targeting experiment. This unit describes detailed step-by-step protocols, reagents, equipment, and strategies needed for the successful generation of gene knockout embryonic stem cells using homologous recombination technologies. PMID:19731225

  3. Resident corneal c-fms+ macrophages and dendritic cells mediate early cellular infiltration in adenovirus keratitis

    PubMed Central

    Ramke, Mirja; Zhou, Xiaohong; Materne, Emma Caroline; Rajaiya, Jaya; Chodosh, James

    2016-01-01

    The cornea contains a heterogeneous population of antigen-presenting cells with the capacity to contribute to immune responses. Adenovirus keratitis is a severe corneal infection with acute and chronic phases. The role of resident corneal antigen-presenting cells in adenovirus keratitis has not been studied. We utilized transgenic MaFIA mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, in a mouse model of adenovirus keratitis. Clinical keratitis and recruitment of myeloperoxidase and CD45+ cells were diminished in c-fms depleted, adenovirus infected mice, as compared to controls, consistent with a role for myeloid-lineage cells in adenovirus keratitis. PMID:27185163

  4. Resident corneal c-fms(+) macrophages and dendritic cells mediate early cellular infiltration in adenovirus keratitis.

    PubMed

    Ramke, Mirja; Zhou, Xiaohong; Materne, Emma Caroline; Rajaiya, Jaya; Chodosh, James

    2016-06-01

    The cornea contains a heterogeneous population of antigen-presenting cells with the capacity to contribute to immune responses. Adenovirus keratitis is a severe corneal infection with acute and chronic phases. The role of resident corneal antigen-presenting cells in adenovirus keratitis has not been studied. We utilized transgenic MaFIA mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, in a mouse model of adenovirus keratitis. Clinical keratitis and recruitment of myeloperoxidase and CD45(+) cells were diminished in c-fms depleted, adenovirus infected mice, as compared to controls, consistent with a role for myeloid-lineage cells in adenovirus keratitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Dendritic cell fate is determined by BCL11A

    PubMed Central

    Ippolito, Gregory C.; Dekker, Joseph D.; Wang, Yui-Hsi; Lee, Bum-Kyu; Shaffer, Arthur L.; Lin, Jian; Wall, Jason K.; Lee, Baeck-Seung; Staudt, Louis M.; Liu, Yong-Jun; Iyer, Vishwanath R.; Tucker, Haley O.

    2014-01-01

    The plasmacytoid dendritic cell (pDC) is vital to the coordinated action of innate and adaptive immunity. pDC development has not been unequivocally traced, nor has its transcriptional regulatory network been fully clarified. Here we confirm an essential requirement for the BCL11A transcription factor in fetal pDC development, and demonstrate this lineage-specific requirement in the adult organism. Furthermore, we identify BCL11A gene targets and provide a molecular mechanism for its action in pDC commitment. Embryonic germ-line deletion of Bcl11a revealed an absolute cellular, molecular, and functional absence of pDCs in fetal mice. In adults, deletion of Bcl11a in hematopoietic stem cells resulted in perturbed yet continued generation of progenitors, loss of downstream pDC and B-cell lineages, and persisting myeloid, conventional dendritic, and T-cell lineages. Challenge with virus resulted in a marked reduction of antiviral response in conditionally deleted adults. Genome-wide analyses of BCL11A DNA binding and expression revealed that BCL11A regulates transcription of E2-2 and other pDC differentiation modulators, including ID2 and MTG16. Our results identify BCL11A as an essential, lineage-specific factor that regulates pDC development, supporting a model wherein differentiation into pDCs represents a primed “default” pathway for common dendritic cell progenitors. PMID:24591644

  6. Continuous single cell imaging reveals sequential steps of plasmacytoid dendritic cell development from common dendritic cell progenitors

    PubMed Central

    Dursun, Ezgi; Endele, Max; Musumeci, Andrea; Failmezger, Henrik; Wang, Shu-Hung; Tresch, Achim; Schroeder, Timm; Krug, Anne B.

    2016-01-01

    Functionally distinct plasmacytoid and conventional dendritic cells (pDC and cDC) shape innate and adaptive immunity. They are derived from common dendritic cell progenitors (CDPs) in the murine bone marrow, which give rise to CD11c+ MHCII− precursors with early commitment to DC subpopulations. In this study, we dissect pDC development from CDP into an ordered sequence of differentiation events by monitoring the expression of CD11c, MHC class II, Siglec H and CCR9 in CDP cultures by continuous single cell imaging and tracking. Analysis of CDP genealogies revealed a stepwise differentiation of CDPs into pDCs in a part of the CDP colonies. This developmental pathway involved an early CD11c+ SiglecH− pre-DC stage and a Siglec H+ CCR9low precursor stage, which was followed rapidly by upregulation of CCR9 indicating final pDC differentiation. In the majority of the remaining CDP pedigrees however the Siglec H+ CCR9low precursor state was maintained for several generations. Thus, although a fraction of CDPs transits through precursor stages rapidly to give rise to a first wave of pDCs, the majority of CDP progeny differentiate more slowly and give rise to longer lived precursor cells which are poised to differentiate on demand. PMID:27892478

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

    PubMed

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

    2014-10-15

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

  8. Plasmacytoid dendritic cells protect against atherosclerosis by tuning T cell proliferation and activity

    PubMed Central

    Daissormont, Isabelle T.M.N.; Christ, Anette; Temmerman, Lieve; Millares, Stefan Sampedro; Seijkens, Tom; Rousch, Mat; Poggi, Marjorie; Boon, Louis; van der Loos, Chris; Daemen, Mat; Lutgens, Esther; Halvorsen, Bente; Aukrust, Pal; Janssen, Edith; Biessen, Erik A.L.

    2011-01-01

    Rationale Unlike conventional dendritic cells (cDC), plasmacytoid DCs (pDC) are poor in antigen presentation and critical for type I interferon response. While proposed to be present in human atherosclerotic lesions, their role in atherosclerosis remains elusive. Objective To investigate the role of pDC in atherosclerosis. Methods and Results We show that pDC are scarcely present in human atherosclerotic lesions, and almost absent in mouse plaques. Surprisingly, pDC depletion by 120G8 mAb administration was seen to promote plaque T cell accumulation and exacerbate lesion development and progression in LDLr−/− mice. PDC depletion was accompanied by increased CD4+ T cell proliferation, IFN-γ expression by splenic T cells and plasma IFN-γ levels. Lymphoid tissue pDC from atherosclerotic mice showed increased indoleamine 2,3-dioxygenase (IDO) expression and IDO blockage abrogated the pDC suppressive effect on T cell proliferation. Conclusion Our data reveal a protective role for pDC in atherosclerosis, possibly by dampening T cell proliferation and activity in peripheral lymphoid tissue, rendering pDC an interesting target for future therapeutic interventions. PMID:22021930

  9. Emitter formation in dendritic web silicon solar cells

    NASA Technical Reports Server (NTRS)

    Meier, D. L.; Rohatgi, A.; Campbell, R. B.; Alexander, P.; Fonash, S. J.; Singh, R.

    1984-01-01

    The use of liquid dopants and liquid masks for p-n junction formation in dendritic web solar cells was investigated and found to be equivalent to the use of gaseous dopants and CVD SiO2 masks previously used. This results in a projected cost reduction of 0.02 1980$/Watt for a 25 MW/year production line, and makes possible junction formation processes having a higher throughput than more conventional processes. The effect of a low-energy (0.4 keV) hydrogen ion implant on dendritic web solar cells was also investigated. Such an implant was observed to improve Voc and Jsc substantially. Measurements of internal quantum efficiency suggest that it is the base of the cell, rather than the emitter, which benefits from the hydrogen implant. The diffusion length for electrons in the p-type base increased from 53 microns to 150 microns in one case, with dendritic web cell efficiency being boosted to 15.2 percent. The mechanism by which low-energy hydrogen ions can penetrate deeply into the silicon to effect the observed improvement is not known at this time.

  10. Dendritic Guanidines as Efficient Analogues of Cell Penetrating Peptides

    PubMed Central

    Bonduelle, Colin V.; Gillies, Elizabeth R.

    2010-01-01

    The widespread application of cell penetrating agents to clinical therapeutics and imaging agents relies on the ability to prepare them on a large scale and to readily conjugate them to their cargos. Dendritic analogues of cell penetrating peptides, with multiple guanidine groups on their peripheries offer advantages as their high symmetry allows them to be efficiently synthesized, while orthogonal functionalities at their focal points allow them to be conjugated to cargo using simple synthetic methods. Their chemical structures and properties are also highly tunable as their flexibility and the number of guanidine groups can be tuned by altering the dendritic backbone or the linkages to the guanidine groups. This review describes the development of cell-penetrating dendrimers based on several different backbones, their structure-property relationships, and comparisons of their efficacies with those of known cell penetrating peptides. The toxicities of these dendritic guanidines are also reported as well as their application towards the intracellular delivery of biologically significant cargos including proteins and nanoparticles. PMID:27713272

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

    PubMed Central

    Xiao, Hui; Wang, Denan; Franc, Nathalie C.; Jan, Lily Yeh; Jan, Yuh-Nung

    2014-01-01

    SUMMARY During developmental remodeling, neurites destined for pruning often degenerate on-site. Physical injury also induces degeneration of neurites distal to the injury site. Prompt clearance of degenerating neurites is important for maintaining tissue homeostasis and preventing inflammatory responses. Here we show that in both dendrite pruning and dendrite injury of Drosophila sensory neurons, epidermal cells rather than hemocytes are the primary phagocytes in clearing degenerating dendrites. Epidermal cells act via Draper-mediated recognition to facilitate dendrite degeneration and to engulf and degrade degenerating dendrites. Using multiple dendritic membrane markers to trace phagocytosis, we show that two members of the CD36 family, croquemort (crq) and debris buster (dsb), act at distinct stages of phagosome maturation for dendrite clearance. Our finding reveals the physiological importance of coordination between neurons and their surrounding epidermis, for both dendrite fragmentation and clearance. PMID:24412417

  12. 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

  13. Antigen Presenting Properties of a Myeloid Dendritic-Like Cell in Murine Spleen

    PubMed Central

    Hey, Ying-ying; O’Neill, Helen C.

    2016-01-01

    This paper distinguishes a rare subset of myeloid dendritic-like cells found in mouse spleen from conventional (c) dendritic cells (DC) in terms of phenotype, function and gene expression. These cells are tentatively named “L-DC” since they resemble dendritic-like cells produced in longterm cultures of spleen. L-DC can be distinguished on the basis of their unique phenotype as CD11bhiCD11cloMHCII-CD43+Ly6C-Ly6G-Siglec-F- cells. They demonstrate similar ability as cDC to uptake and retain complex antigens like mannan via mannose receptors, but much lower ability to endocytose and retain soluble antigen. While L-DC differ from cDC by their inability to activate CD4+ T cells, they are capable of antigen cross-presentation for activation of CD8+ T cells, although less effectively so than the cDC subsets. In terms of gene expression, CD8- cDC and CD8+ cDC are quite distinct from L-DC. CD8+ cDC are distinguishable from the other two subsets by expression of CD24a, Clec9a, Xcr1 and Tlr11, while CD8- cDC are distinguished by expression of Ccnd1 and H-2Eb2. L-DC are distinct from the two cDC subsets through upregulated expression of Clec4a3, Emr4, Itgam, Csf1r and CD300ld. The L-DC gene profile is quite distinct from that of cDC, confirming a myeloid cell type with distinct antigen presenting properties. PMID:27654936

  14. Antigen Presenting Properties of a Myeloid Dendritic-Like Cell in Murine Spleen.

    PubMed

    Hey, Ying-Ying; O'Neill, Helen C

    This paper distinguishes a rare subset of myeloid dendritic-like cells found in mouse spleen from conventional (c) dendritic cells (DC) in terms of phenotype, function and gene expression. These cells are tentatively named "L-DC" since they resemble dendritic-like cells produced in longterm cultures of spleen. L-DC can be distinguished on the basis of their unique phenotype as CD11bhiCD11cloMHCII-CD43+Ly6C-Ly6G-Siglec-F- cells. They demonstrate similar ability as cDC to uptake and retain complex antigens like mannan via mannose receptors, but much lower ability to endocytose and retain soluble antigen. While L-DC differ from cDC by their inability to activate CD4+ T cells, they are capable of antigen cross-presentation for activation of CD8+ T cells, although less effectively so than the cDC subsets. In terms of gene expression, CD8- cDC and CD8+ cDC are quite distinct from L-DC. CD8+ cDC are distinguishable from the other two subsets by expression of CD24a, Clec9a, Xcr1 and Tlr11, while CD8- cDC are distinguished by expression of Ccnd1 and H-2Eb2. L-DC are distinct from the two cDC subsets through upregulated expression of Clec4a3, Emr4, Itgam, Csf1r and CD300ld. The L-DC gene profile is quite distinct from that of cDC, confirming a myeloid cell type with distinct antigen presenting properties.

  15. Extended protection capabilities of an immature dendritic-cell targeting malaria sporozoite vaccine.

    PubMed

    Luo, Kun; Zavala, Fidel; Gordy, James; Zhang, Hong; Markham, Richard B

    2017-03-22

    Mouse studies evaluating candidate malaria vaccines have typically examined protective efficacy over the relatively short time frames of several weeks after the final of multiple immunizations. The current study examines the protective ability in a mouse model system of a novel protein vaccine construct in which the adjuvant polyinosinic polycytidilic acid (poly(I:C)) is used in combination with a vaccine in which the immature dendritic cell targeting chemokine, macrophage inflammatory protein 3 alpha (MIP3α), is fused to the circumsporozoite protein (CSP) of Plasmodium falciparum (P. falciparum). Two vaccinations, three weeks apart, elicited extraordinarily high, MIP3α-dependent antibody responses. MIP3α was able to target the vaccine to the CCR6 receptor found predominantly on immature dendritic cells and significantly enhanced the cellular influx at the vaccination site. At three and 23 weeks after the final of two immunizations, mice were challenged by intravenous injection of 5×10(3) transgenic Plasmodium berghei sporozoites expressing P. falciparum CSP, a challenge dose approximately one order of magnitude greater than that which is encountered after mosquito bite in the clinical setting. A ninety-seven percent reduction in liver sporozoite load was observed at both time points, 23 weeks being the last time point tested.

  16. Immune tolerance of mice allogenic tooth transplantation induced by immature dendritic cells

    PubMed Central

    Li, Wenying; Deng, Feng; Wang, Yu; Ma, Ce; Wang, Yurong

    2015-01-01

    As a common procedure in dentistry for replacing a missing tooth, allogenic tooth transplantation has encountered many difficulties in the clinical application because of immunological rejection. It is hypothesized that immature dendritic cell injection might be a potential alternative method to avoid or alleviate immunological rejection in allogenic tooth transplantation. To test this hypothesis, a mouse model of allogenic and autogeneic tooth transplantation was to established test the immunosuppressive effect of immature dendritic cells (imDCs) derived from donor bone marrows on transplant rejection in allogenic tooth transplantation. 2 × 106 imDCs generated with 50 U/ml GM-CSF were injected to each recipient mouse by two ways: tail vein injection 7 days before transplantation or regional dermal injection at day 0 and day 3 after transplantation. Groups of autogeneic tooth transplantation and allogenic tooth transplantation without any treatment were set as control groups. The effects were evaluated with histopathology and immunohistochemistry. We found there was no obvious rejection in autogeneic tooth transplantation group; tail intravenous injection group showed obviously alleviated rejection while local injection group and none-treatment allogenic tooth transplantation group both showed severe rejection. Our results suggested that the rejection of allogenic tooth transplantation could be alleviated by tail vein injection of donor bone marrow-derived imDCs though it could not be completely eliminated. The clinical application of imDCs in allogenic tooth transplantation still needs further deep research. PMID:26131099

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

    PubMed

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

    2006-04-01

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

  18. Computer Tomography Imaging Findings of Abdominal Follicular Dendritic Cell Sarcoma

    PubMed Central

    Li, Jing; Geng, Zhi-Jun; Xie, Chuan-Miao; Zhang, Xin-Ke; Chen, Rui-Ying; Cai, Pei-Qiang; Lv, Xiao-Fei

    2016-01-01

    Abstract Follicular dendritic cell sarcoma (FDCS) is a neoplasm that arises from follicular dendritic cells. FDCSs originating in the abdomen are extremely rare. Clinically, they often mimic a wide variety of other abdominal tumors, and correct preoperative diagnosis is often a challenging task. To date, only scattered cases of abdominal FDCS have been reported and few data are available on their radiological features. Here we present the computer tomography imaging findings of 5 patients with surgically and pathologically demonstrated abdominal FDCS. An abdominal FDCS should be included in the differential diagnosis when single or multiple masses with relatively large size, well- or ill-defined borders, complex internal architecture with marked internal necrosis and/or focal calcification, and heterogeneous enhancement with “rapid wash-in and slow wash-out” or “progressive enhancement” enhancement patterns in the solid component are seen. PMID:26735543

  19. Targeting human dendritic cells in situ to improve vaccines.

    PubMed

    Sehgal, Kartik; Dhodapkar, Kavita M; Dhodapkar, Madhav V

    2014-11-01

    Dendritic cells (DCs) provide a critical link between innate and adaptive immunity. The potent antigen presenting properties of DCs makes them a valuable target for the delivery of immunogenic cargo. Recent clinical studies describing in situ DC targeting with antibody-mediated targeting of DC receptor through DEC-205 provide new opportunities for the clinical application of DC-targeted vaccines. Further advances with nanoparticle vectors which can encapsulate antigens and adjuvants within the same compartment and be targeted against diverse DC subsets also represent an attractive strategy for targeting DCs. This review provides a brief summary of the rationale behind targeting dendritic cells in situ, the existing pre-clinical and clinical data on these vaccines and challenges faced by the next generation DC-targeted vaccines. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Mycobacterium bovis BCG-infected neutrophils and dendritic cells cooperate to induce specific T cell responses in humans and mice.

    PubMed

    Morel, Céline; Badell, Edgar; Abadie, Valérie; Robledo, Macarena; Setterblad, Niclas; Gluckman, Jean Claude; Gicquel, Brigitte; Boudaly, Sarah; Winter, Nathalie

    2008-02-01

    Neutrophils are increasingly thought to modulate dendritic cell (DC) functions. We investigated the role of the neutrophil-DC partnership in the response to Mycobacterium bovis BCG-the vaccine used against tuberculosis. We compared neutrophil-DC crosstalk in humans and mice, searching for functional differences. In both species, neutrophils captured fluorescent BCG-enhanced green fluorescent protein (EGFP) and were more phagocytic than DC. Non-apoptotic BCG-infected neutrophils clustered with immature DC, establishing intimate contacts with dendrites, at which fluorescent intact bacilli were observed. Physical interactions between neutrophils and DC were required for DC activation. Human BCG-infected DC produced interleukin (IL)-10, an inhibitory cytokine, whereas DC exposed to BCG-infected neutrophils produced low to undetectable amounts of the cytokine. Mouse BCG-infected neutrophils induced sustained IL-2 production by DC. Human DC exposed to BCG-infected neutrophils stimulated recall T cell reactivity from vaccinated donors. Mouse DC infected with recombinant ovalbumin (OVA)-producing BCG (rBCG(ova)) elicited proliferation of TCR-OVA-transgenic CD4 and CD8 T cells. Moreover, exposing DC to rBCG(ova)-infected neutrophils enhanced OVA presentation. Thus, in mice and humans, neutrophils help DC to cross-present BCG antigens to T cells. Our results suggest that this "ménage à trois" involving neutrophils, DC and T cells plays a major role in the immune response to BCG.

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

    PubMed

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

    2010-12-15

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

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

    DTIC Science & Technology

    2007-11-02

    significance of coiling phagocy- tosis for disease pathogenesis has yet to be elucidated, it is a sub- ject that surely warrants further investigation. B...Schmaljohn. 2003. Ebola and marburg viruses replicate in monocyte-derived dendritic cells without inducing the pro- duction of cytokines and full maturation...Journal of Immunology, 2005, 174: 5545–5552. I nhalational anthrax, a disease that was exploited for bioter-rorism (1), is most often fatal and causes

  3. Dendritic web-type solar cell mini-modules

    NASA Technical Reports Server (NTRS)

    Campbell, R. B.

    1985-01-01

    Twenty-five minimodules composed of dendritic web solar cells with nominal glass size of 12 by 40 cm were provided for study. The modules were identical with respect to design, materials, and manufacturing and assembly processes to full scale modules. The modules were also electrically functional. These minimodules were fabricated to provide test vehicle for environmental testing and to assess reliability of process and design procedures. The module design and performance are outlined.

  4. Modulatory effects on dendritic cells by human herpesvirus 6

    PubMed Central

    Gustafsson, Rasmus; Svensson, Mattias; Fogdell-Hahn, Anna

    2015-01-01

    Human herpesvirus 6A and 6B are β-herpesviruses approaching 100% seroprevalance worldwide. These viruses are involved in several clinical syndromes and have important immunomodulatory effects. Dendritic cells (DC) are key players in innate and adaptive immunity. Accordingly, DC are implicated in the pathogenesis of many human diseases, including infections. In this review the effects of HHV-6 infection on DC will be discussed. PMID:25983728

  5. Guardians of the Gut – Murine Intestinal Macrophages and Dendritic Cells

    PubMed Central

    Gross, Mor; Salame, Tomer-Meir; Jung, Steffen

    2015-01-01

    Intestinal mononuclear phagocytes find themselves in a unique environment, most prominently characterized by its constant exposure to commensal microbiota and food antigens. This anatomic setting has resulted in a number of specializations of the intestinal mononuclear phagocyte compartment that collectively contribute the unique steady state immune landscape of the healthy gut, including homeostatic innate lymphoid cells, B, and T cell compartments. As in other organs, macrophages and dendritic cells (DCs) orchestrate in addition the immune defense against pathogens, both in lymph nodes and mucosa-associated lymphoid tissue. Here, we will discuss origins and functions of intestinal DCs and macrophages and their respective subsets, focusing largely on the mouse and cells residing in the lamina propria. PMID:26082775

  6. 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.

  7. 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

  8. A novel peptide targeting Clec9a on dendritic cell for cancer immunotherapy

    PubMed Central

    Yan, Zhongyi; Wu, Yahong; Du, Jiangfeng; Li, Guodong; Wang, Shengdian; Cao, Wenpeng; Zhou, Xiuman; Wu, Chunjing; Zhang, Dan; Jing, Xueli; Li, Yifan; Wang, Hongfei; Gao, Yanfeng; Qi, Yuanming

    2016-01-01

    Dendritic cells (DCs) are professional antigen-presenting cells with antigen recognition molecules on the surface. Clec9a is selectively expressed on mouse CD8a+ DCs and CD103+ DCs subsets, which are functionally similar to human BDCA3+ DCs. It is reported that Clec9a is responsible for the antigen cross-presentation of these DC subsets. In the present study, by using phage display technique, we discovered a novel peptide WH, which can selectively bind to mouse Flt3L induced Clec9a+ DCs or Clec9a over-expressed HEK-293T cells. Furthermore, by using computer-aided docking model and mutation assay, we observed that Asp248 and Trp250 are two key residues for Clec9a to bind with peptide WH. When coupled with OVA257-264 epitope, peptide WH can significantly enhance the ability of Clec9a+ DCs to activate OVA-specific CD8+ T cells, which elicit strong ability to secret IFN-γ, express perforin and granzyme B mRNA. In B16-OVA lung metastasis mouse model, WH-OVA257-264 fusion peptide can also enhance the activation of CD8+ T cells and decrease the lung metastasis loci. All these results suggested that peptide WH could be considered as an antigen delivery carrier targeting Clec9a+ DCs for cancer immunotherapy. PMID:27250027

  9. Jet exhaust particles alter human dendritic cell maturation.

    PubMed

    Ferry, D; Rolland, C; Delhaye, D; Barlesi, F; Robert, P; Bongrand, P; Vitte, Joana

    2011-03-01

    Among combustion-derived air pollutants, little is known about jet kerosene characteristics and effects. Particles yielded by experimental kerosene combustion in a jet engine were characterized with electron microscopy and X-ray energy dispersive spectroscopy. Immature human monocyte-derived dendritic cells were exposed for 18 h to 10, 25 or 100 μg/mL jet exhaust particles and/or Escherichia coli-derived endotoxin. Antigen-presenting and costimulation molecules (HLA DR, CD40, CD80, CD86, CD11c), tumor necrosis factor-α and interleukin-10 production were measured. The primary particles of jet exhaust are spherical (9.9 nm), carbonaceous and exert an adjuvant effect on human monocyte-derived dendritic cell maturation in vitro. Concomitant particle and endotoxin stimulation induced a high cytokine production with low antigen-presenting molecules; particle contact prior to endotoxin contact led to an opposite phenotype. Finally, low cytokine production and high costimulation molecules were present when particle adjunction followed endotoxin contact. Jet exhaust particles act as adjuvants to endotoxin-induced dendritic cell maturation, suggesting possible implications for human health and a role for the time pattern of infectious and pollutant interplay.

  10. 3D visualization of HIV transfer at the virological synapse between dendritic cells and T cells

    PubMed Central

    Felts, Richard L.; Narayan, Kedar; Estes, Jacob D.; Shi, Dan; Trubey, Charles M.; Fu, Jing; Hartnell, Lisa M.; Ruthel, Gordon T.; Schneider, Douglas K.; Nagashima, Kunio; Bess, Julian W.; Bavari, Sina; Lowekamp, Bradley C.; Bliss, Donald; Lifson, Jeffrey D.; Subramaniam, Sriram

    2010-01-01

    The efficiency of HIV infection is greatly enhanced when the virus is delivered at conjugates between CD4+ T cells and virus-bearing antigen-presenting cells such as macrophages or dendritic cells via specialized structures known as virological synapses. Using ion abrasion SEM, electron tomography, and superresolution light microscopy, we have analyzed the spatial architecture of cell-cell contacts and distribution of HIV virions at virological synapses formed between mature dendritic cells and T cells. We demonstrate the striking envelopment of T cells by sheet-like membrane extensions derived from mature dendritic cells, resulting in a shielded region for formation of virological synapses. Within the synapse, filopodial extensions emanating from CD4+ T cells make contact with HIV virions sequestered deep within a 3D network of surface-accessible compartments in the dendritic cell. Viruses are detected at the membrane surfaces of both dendritic cells and T cells, but virions are not released passively at the synapse; instead, virus transfer requires the engagement of T-cell CD4 receptors. The relative seclusion of T cells from the extracellular milieu, the burial of the site of HIV transfer, and the receptor-dependent initiation of virion transfer by T cells highlight unique aspects of cell-cell HIV transmission. PMID:20624966

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

    PubMed

    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

    2016-12-16

    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 Ly6C(hi) 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.

  12. 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

  13. Ca2+ imaging of mouse neocortical interneurone dendrites: Ia-type K+ channels control action potential backpropagation

    PubMed Central

    Goldberg, Jesse H; Tamas, Gabor; Yuste, Rafael

    2003-01-01

    GABAergic interneurones are essential in cortical processing, yet the functional properties of their dendrites are still poorly understood. In this first study, we combined two-photon calcium imaging with whole-cell recording and anatomical reconstructions to examine the calcium dynamics during action potential (AP) backpropagation in three types of V1 supragranular interneurones: parvalbumin-positive fast spikers (FS), calretinin-positive irregular spikers (IS), and adapting cells (AD). Somatically generated APs actively backpropagated into the dendritic tree and evoked instantaneous calcium accumulations. Although voltage-gated calcium channels were expressed throughout the dendritic arbor, calcium signals during backpropagation of both single APs and AP trains were restricted to proximal dendrites. This spatial control of AP backpropagation was mediated by Ia-type potassium currents and could be mitigated by by previous synaptic activity. Further, we observed supralinear summation of calcium signals in synaptically activated dendritic compartments. Together, these findings indicate that in interneurons, dendritic AP propagation is synaptically regulated. We propose that interneurones have a perisomatic and a distal dendritic functional compartment, with different integrative functions. PMID:12844506

  14. Dendritic Cell Immunotherapy Combined with Cytokine-Induced Killer Cells Effectively Suppresses Established Hepatocellular Carcinomas in Mice.

    PubMed

    Jung, Nam-Chul; Lee, Jun-Ho; Choi, Hyun-Ji; Hwang, Sung-Uk; Song, Jie-Young; Seo, Han Geuk; Choi, Jinjung; Jung, Sang Youn; Han, Sung Gu; Lim, Dae-Seog

    2016-08-01

    The response of hepatocellular carcinoma (HCC) to immunotherapy is often disappointing and new strategies are clearly needed. The aim of the present study was to investigate whether cytokine-induced killer (CIK) cells combined with a dendritic cell vaccination enhanced cytotoxicity against hepatocarcinoma tumor cells in an in vivo animal model. CIKs and DCs were prepared from C3H/HeJ mice by conventional methods, the dendritic cell (DC) pulsed with a MH134 cell lysate, DC or CIK alone were used as controls. Cell phenotypes were analyzed by flow cytometry, cytokine secretion levels were determined by enzyme-linked immunosorbent assay (ELISA), and cytotoxicity was assessed by means of an in vitro lactate dehydrogenase (LDH) release assay. A mouse hepatocarcinoma cell MH134-bearing mice model was established to test the in vivo anti-tumor efficacy of the system. CIK cells combined with DC therapy resulted in significant inhibition of tumor growth compared with the control group, whereas the decrease in tumor growth in mice that had been treated with CIK or DC alone did not reach the level of statistical significance. The combination therapy led to a further increase in the population of cytotoxic T cells (CTLs) in vivo, compared to the CIK or DC alone therapy. In addition, the combination therapy significantly enhanced cytotoxic activity against MH134 cells. Taken together, these results show that a DC + CIK vaccination is more effective than DC or CIK alone therapy for the treatment of hepatocarcinoma cancer.

  15. Suppressing The Growth Of Dendrites In Secondary Li Cells

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  16. How helminths use excretory secretory fractions to modulate dendritic cells

    PubMed Central

    White, Rhiannon R.; Artavanis-Tsakonas, Katerina

    2012-01-01

    It is well known that helminth parasites have immunomodulatory effects on their hosts. They characteristically cause a skew toward TH2 immunity, stimulate Treg cells while simultaneously inhibiting TH1 and TH17 responses. Additionally, they induce eosinophilia and extensive IgE release. The exact mechanism of how the worms achieve this effect have yet to be fully elucidated; however, parasite-derived secretions and their interaction with antigen presenting cells have been centrally implicated. Herein, we will review the effects of helminth excretory-secretory fractions on dendritic cells and discuss how this interaction is crucial in shaping the host response. PMID:23221477

  17. Cross-dressed dendritic cells drive memory CD8+ T-cell activation after viral infection.

    PubMed

    Wakim, Linda M; Bevan, Michael J

    2011-03-31

    After an infection, cytotoxic T lymphocyte precursors proliferate and become effector cells by recognizing foreign peptides in the groove of major histocompatibility complex (MHC) class I molecules expressed by antigen-presenting cells (APCs). Professional APCs specialized for T-cell activation acquire viral antigen either by becoming infected themselves (direct presentation) or by phagocytosis of infected cells, followed by transfer of antigen to the cytosol, processing and MHC class I loading in a process referred to as cross-presentation. An alternative way, referred to as 'cross-dressing', by which an uninfected APC could present antigen was postulated to be by the transfer of preformed peptide-MHC complexes from the surface of an infected cell to the APC without the need of further processing. Here we show that this mechanism exists and boosts the antiviral response of mouse memory CD8(+) T cells. A number of publications have demonstrated sharing of peptide-loaded MHC molecules in vitro. Our in vitro experiments demonstrate that cross-dressing APCs do not acquire peptide-MHC complexes in the form of exosomes released by donor cells. Rather, the APCs and donor cells have to contact each other for the transfer to occur. After a viral infection, we could isolate cross-dressed APCs able to present viral antigen in vitro. Furthermore, using the diphtheria toxin system to selectively eliminate APCs that could only acquire viral peptide-MHC complexes by cross-dressing, we show that such presentation can promote the expansion of resting memory T cells. Notably, naive T cells were excluded from taking part in the response. Cross-dressing is a mechanism of antigen presentation used by dendritic cells that may have a significant role in activating previously primed CD8(+) T cells.

  18. Kaposi's sarcoma-associated herpesvirus infection of bone marrow dendritic cells from multiple myeloma patients.

    PubMed

    Rettig, M B; Ma, H J; Vescio, R A; Põld, M; Schiller, G; Belson, D; Savage, A; Nishikubo, C; Wu, C; Fraser, J; Said, J W; Berenson, J R

    1997-06-20

    Kaposi's sarcoma-associated herpesvirus (KSHV) was found in the bone marrow dendritic cells of multiple myeloma patients but not in malignant plasma cells or bone marrow dendritic cells from normal individuals or patients with other malignancies. In addition the virus was detected in the bone marrow dendritic cells from two out of eight patients with monoclonal gammopathy of undetermined significance (MGUS), a precursor to myeloma. Viral interleukin-6, the human homolog of which is a growth factor for myeloma, was found to be transcribed in the myeloma bone marrow dendritic cells. KSHV may be required for transformation from MGUS to myeloma and perpetuate the growth of malignant plasma cells.

  19. Mycobacterium-Infected Dendritic Cells Disseminate Granulomatous Inflammation.

    PubMed

    Harding, Jeffrey S; Rayasam, Aditya; Schreiber, Heidi A; Fabry, Zsuzsanna; Sandor, Matyas

    2015-10-30

    The disappearance and reformation of granulomas during tuberculosis has been described using PET/CT/X-ray in both human clinical settings and animal models, but the mechanisms of granuloma reformation during active disease remains unclear. Granulomas can recruit inflammatory dendritic cells (iDCs) that can regulate local T-cell responses and can carry bacteria into the lymph nodes, which is crucial for generating systemic T-cell responses against mycobacteria. Here, we report that a subset of mycobacterium-infected iDCs are associated with bacteria-specific T-cells in infected tissue, outside the granuloma, and that this results in the formation of new and/or larger multi-focal lesions. Mycobacterium-infected iDCs express less CCR7 and migrate less efficiently compared to the non-infected iDCs, which may support T-cell capture in granulomatous tissue. Capture may reduce antigen availability in the lymph node, thereby decreasing systemic priming, resulting in a possible regulatory loop between systemic T-cell responses and granuloma reformation. T-cell/infected iDCs clusters outside the granuloma can be detected during the acute and chronic phase of BCG and Mtb infection. Our studies suggest a direct role for inflammatory dendritic cells in the dissemination of granulomatous inflammation.

  20. Mycobacterium-Infected Dendritic Cells Disseminate Granulomatous Inflammation

    PubMed Central

    Harding, Jeffrey S.; Rayasam, Aditya; Schreiber, Heidi A.; Fabry, Zsuzsanna; Sandor, Matyas

    2015-01-01

    The disappearance and reformation of granulomas during tuberculosis has been described using PET/CT/X-ray in both human clinical settings and animal models, but the mechanisms of granuloma reformation during active disease remains unclear. Granulomas can recruit inflammatory dendritic cells (iDCs) that can regulate local T-cell responses and can carry bacteria into the lymph nodes, which is crucial for generating systemic T-cell responses against mycobacteria. Here, we report that a subset of mycobacterium-infected iDCs are associated with bacteria-specific T-cells in infected tissue, outside the granuloma, and that this results in the formation of new and/or larger multi-focal lesions. Mycobacterium-infected iDCs express less CCR7 and migrate less efficiently compared to the non-infected iDCs, which may support T-cell capture in granulomatous tissue. Capture may reduce antigen availability in the lymph node, thereby decreasing systemic priming, resulting in a possible regulatory loop between systemic T-cell responses and granuloma reformation. T-cell/infected iDCs clusters outside the granuloma can be detected during the acute and chronic phase of BCG and Mtb infection. Our studies suggest a direct role for inflammatory dendritic cells in the dissemination of granulomatous inflammation. PMID:26515292

  1. Functional Properties of Dendritic Gap Junctions in Cerebellar Golgi Cells.

    PubMed

    Szoboszlay, Miklos; Lőrincz, Andrea; Lanore, Frederic; Vervaeke, Koen; Silver, R Angus; Nusser, Zoltan

    2016-06-01

    The strength and variability of electrical synaptic connections between GABAergic interneurons are key determinants of spike synchrony within neuronal networks. However, little is known about how electrical coupling strength is determined due to the inaccessibility of gap junctions on the dendritic tree. We investigated the properties of gap junctions in cerebellar interneurons by combining paired somato-somatic and somato-dendritic recordings, anatomical reconstructions, immunohistochemistry, electron microscopy, and modeling. By fitting detailed compartmental models of Golgi cells to their somato-dendritic voltage responses, we determined their passive electrical properties and the mean gap junction conductance (0.9 nS). Connexin36 immunofluorescence and freeze-fracture replica immunogold labeling revealed a large variability in gap junction size and that only 18% of the 340 channels are open in each plaque. Our results establish that the number of gap junctions per connection is the main determinant of both the strength and variability in electrical coupling between Golgi cells. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Cross-protective efficacy of dendritic cells targeting conserved influenza virus antigen expressed by Lactobacillus plantarum

    PubMed Central

    Yang, Wen-Tao; Shi, Shao-Hua; Yang, Gui-Lian; Jiang, Yan-Long; Zhao, Liang; Li, Yu; Wang, Chun-Feng

    2016-01-01

    Avian influenza virus (AIV) can infect birds and mammals, including humans, and are thus a serious threat to public health. Vaccination is vital for controlling AIV circulation. In this study, we generated a recombinant lactobacillus expressing the NP-M1-DCpep of H9N2 avian influenza virus and evaluated the activation effect of NC8-pSIP409-NP-M1-DCpep on dendritic cells (DCs) in a mouse model. The specific mucosal antibody responses and B and T cell responses in lymphoid tissues were also characterized. Importantly, we confirmed that specific CD8 T cells presented in vitro and antigen-specific cytotoxicity (activated the expression of CD107a) and in vivo antigen-specific cytotoxicity after vaccination. The adoptive transfer of NC8-pSIP409-NP-M1-DCpep-primed CD8+ T cells into NOD-SCID mice resulted in effective protection against mouse-adapted AIV infection. In addition, we observed protection in immunized mice challenged with mouse-adapted H9N2 AIV and H1N1 influenza virus, as evidenced by reductions in the lung virus titers, improvements in lung pathology, and weight loss and complete survival. Our data are promising for the generation of effective, non-traditional influenza vaccines against AIVs. PMID:28004787

  3. Influence of organophosphate poisoning on human dendritic cells.

    PubMed

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

    2013-12-05

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

  4. Acetyl-L-carnitine improves behavior and dendritic morphology in a mouse model of Rett syndrome.

    PubMed

    Schaevitz, Laura R; Nicolai, Raffaella; Lopez, Carla M; D'Iddio, Stefania; Iannoni, Emerenziana; Berger-Sweeney, Joanne E

    2012-01-01

    Rett syndrome (RTT) is a devastating neurodevelopmental disorder affecting 1 in 10,000 girls. Approximately 90% of cases are caused by spontaneous mutations in the X-linked gene encoding methyl-CpG-binding protein 2 (MeCP2). Girls with RTT suffer from severe motor, respiratory, cognitive and social abnormalities attributed to early deficits in synaptic connectivity which manifest in the adult as a myriad of physiological and anatomical abnormalities including, but not limited to, dimished dendritic complexity. Supplementation with acetyl-L-carnitine (ALC), an acetyl group donor, ameliorates motor and cognitive deficits in other disease models through a variety of mechanisms including altering patterns of histone acetylation resulting in changes in gene expression, and stimulating biosynthetic pathways such as acetylcholine. We hypothesized ALC treatment during critical periods in cortical development would promote normal synaptic maturation, and continuing treatment would improve behavioral deficits in the Mecp2(1lox) mouse model of RTT. In this study, wildtype and Mecp2(1lox) mutant mice received daily injections of ALC from birth until death (postnatal day 47). General health, motor, respiratory, and cognitive functions were assessed at several time points during symptom progression. ALC improved weight gain, grip strength, activity levels, prevented metabolic abnormalities and modestly improved cognitive function in Mecp2 null mice early in the course of treatment, but did not significantly improve motor or cognitive functions assessed later in life. ALC treatment from birth was associated with an almost complete rescue of hippocampal dendritic morphology abnormalities with no discernable side effects in the mutant mice. Therefore, ALC appears to be a promising therapeutic approach to treating early RTT symptoms and may be useful in combination with other therapies.

  5. Dendritic cell based PSMA immunotherapy for prostate cancer using a CD40-targeted adenovirus vector.

    PubMed

    Williams, Briana Jill; Bhatia, Shilpa; Adams, Lisa K; Boling, Susan; Carroll, Jennifer L; Li, Xiao-Lin; Rogers, Donna L; Korokhov, Nikolay; Kovesdi, Imre; Pereboev, Alexander V; Curiel, David T; Mathis, J Michael

    2012-01-01

    Human prostate tumor vaccine and gene therapy trials using ex vivo methods to prime dendritic cells (DCs) with prostate specific membrane antigen (PSMA) have been somewhat successful, but to date the lengthy ex vivo manipulation of DCs has limited the widespread clinical utility of this approach. Our goal was to improve upon cancer vaccination with tumor antigens by delivering PSMA via a CD40-targeted adenovirus vector directly to DCs as an efficient means for activation and antigen presentation to T-cells. To test this approach, we developed a mouse model of prostate cancer by generating clonal derivatives of the mouse RM-1 prostate cancer cell line expressing human PSMA (RM-1-PSMA cells). To maximize antigen presentation in target cells, both MHC class I and TAP protein expression was induced in RM-1 cells by transduction with an Ad vector expressing interferon-gamma (Ad5-IFNγ). Administering DCs infected ex vivo with CD40-targeted Ad5-huPSMA, as well as direct intraperitoneal injection of the vector, resulted in high levels of tumor-specific CTL responses against RM-1-PSMA cells pretreated with Ad5-IFNγ as target cells. CD40 targeting significantly improved the therapeutic antitumor efficacy of Ad5-huPSMA encoding PSMA when combined with Ad5-IFNγ in the RM-1-PSMA model. These results suggest that a CD-targeted adenovirus delivering PSMA may be effective clinically for prostate cancer immunotherapy.

  6. Dendritic Cell Based PSMA Immunotherapy for Prostate Cancer Using a CD40-Targeted Adenovirus Vector

    PubMed Central

    Williams, Briana Jill; Bhatia, Shilpa; Adams, Lisa K.; Boling, Susan; Carroll, Jennifer L.; Li, Xiao-Lin; Rogers, Donna L.; Korokhov, Nikolay; Kovesdi, Imre; Pereboev, Alexander V.; Curiel, David T.; Mathis, J. Michael

    2012-01-01

    Human prostate tumor vaccine and gene therapy trials using ex vivo methods to prime dendritic cells (DCs) with prostate specific membrane antigen (PSMA) have been somewhat successful, but to date the lengthy ex vivo manipulation of DCs has limited the widespread clinical utility of this approach. Our goal was to improve upon cancer vaccination with tumor antigens by delivering PSMA via a CD40-targeted adenovirus vector directly to DCs as an efficient means for activation and antigen presentation to T-cells. To test this approach, we developed a mouse model of prostate cancer by generating clonal derivatives of the mouse RM-1 prostate cancer cell line expressing human PSMA (RM-1-PSMA cells). To maximize antigen presentation in target cells, both MHC class I and TAP protein expression was induced in RM-1 cells by transduction with an Ad vector expressing interferon-gamma (Ad5-IFNγ). Administering DCs infected ex vivo with CD40-targeted Ad5-huPSMA, as well as direct intraperitoneal injection of the vector, resulted in high levels of tumor-specific CTL responses against RM-1-PSMA cells pretreated with Ad5-IFNγ as target cells. CD40 targeting significantly improved the therapeutic antitumor efficacy of Ad5-huPSMA encoding PSMA when combined with Ad5-IFNγ in the RM-1-PSMA model. These results suggest that a CD-targeted adenovirus delivering PSMA may be effective clinically for prostate cancer immunotherapy. PMID:23056548

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

    PubMed

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

    2015-10-13

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

  8. 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.

  9. 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

  10. Classification of dendritic cell phenotypes from gene expression data

    PubMed Central

    2011-01-01

    Background The selection of relevant genes for sample classification is a common task in many gene expression studies. Although a number of tools have been developed to identify optimal gene expression signatures, they often generate gene lists that are too long to be exploited clinically. Consequently, researchers in the field try to identify the smallest set of genes that provide good sample classification. We investigated the genome-wide expression of the inflammatory phenotype in dendritic cells. Dendritic cells are a complex group of cells that play a critical role in vertebrate immunity. Therefore, the prediction of the inflammatory phenotype in these cells may help with the selection of immune-modulating compounds. Results A data mining protocol was applied to microarray data for murine cell lines treated with various inflammatory stimuli. The learning and validation data sets consisted of 155 and 49 samples, respectively. The data mining protocol reduced the number of probe sets from 5,802 to 10, then from 10 to 6 and finally from 6 to 3. The performances of a set of supervised classification models were compared. The best accuracy, when using the six following genes --Il12b, Cd40, Socs3, Irgm1, Plin2 and Lgals3bp-- was obtained by Tree Augmented Naïve Bayes and Nearest Neighbour (91.8%). Using the smallest set of three genes --Il12b, Cd40 and Socs3-- the performance remained satisfactory and the best accuracy was with Support Vector Machine (95.9%). These data mining models, using data for the genes Il12b, Cd40 and Socs3, were validated with a human data set consisting of 27 samples. Support Vector Machines (71.4%) and Nearest Neighbour (92.6%) gave the worst performances, but the remaining models correctly classified all the 27 samples. Conclusions The genes selected by the data mining protocol proposed were shown to be informative for discriminating between inflammatory and steady-state phenotypes in dendritic cells. The robustness of the data mining

  11. 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

  12. Targeting antigens through blood dendritic cell antigen 2 (BDCA2) on plasmacytoid dendritic cells promotes immunologic tolerance1

    PubMed Central

    Draves, Kevin E.; Chen, ChangHung; Hayden-Ledbetter, Martha S.; Shlomchik, Mark J.; Kaplan, Daniel H.; Clark, Edward A.

    2014-01-01

    The C-type lectin receptor blood dendritic cell antigen 2 (BDCA2) is expressed exclusively on human plasmacytoid dendritic cells (pDCs) and plays a role in Ag capture, internalization and presentation to T cells. We used transgenic mice that express human BDCA2 and anti-BDCA2 mAbs to deliver Ags directly to BDCA2 on pDCs in vivo. Targeting Ag to pDCs in this manner resulted in significant suppression of Ag-specific CD4+ T cell and Ab responses upon secondary exposure to Ag in the presence of adjuvant. Suppression of Ab responses required both a decrease in effector CD4+ T cells and preservation of Foxp3+ regulatory T cells (Tregs). Reduction in Treg cell numbers following Ag delivery to BDCA2 restored both CD4+ T cell activation and Ab responses, demonstrating that Tregs were required for the observed tolerance. Our results demonstrate that Ag delivery to pDCs through BDCA2 is an effective method to induce immunological tolerance, which may be useful for treating autoimmune diseases or to inhibit unwanted Ab responses. PMID:24829416

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

    PubMed

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

    2015-08-01

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

  14. Leukemia-derived immature dendritic cells differentiate into functionally competent mature dendritic cells that efficiently stimulate T cell responses.

    PubMed

    Cignetti, Alessandro; Vallario, Antonella; Roato, Ilaria; Circosta, Paola; Allione, Bernardino; Casorzo, Laura; Ghia, Paolo; Caligaris-Cappio, Federico

    2004-08-15

    Primary acute myeloid leukemia cells can be induced to differentiate into dendritic cells (DC). In the presence of GM-CSF, TNF-alpha, and/or IL-4, leukemia-derived DC are obtained that display features of immature DC (i-DC). The aim of this study was to determine whether i-DC of leukemic origin could be further differentiated into mature DC (m-DC) and to evaluate the possibility that leukemic m-DC could be effective in vivo as a tumor vaccine. Using CD40L as maturating agent, we show that leukemic i-DC can differentiate into cells that fulfill the phenotypic criteria of m-DC and, compared with normal counterparts, are functionally competent in vitro in terms of: 1) production of cytokines that support T cell activation and proliferation and drive Th1 polarization; 2) generation of autologous CD8(+) CTLs and CD4(+) T cells that are MHC-restricted and leukemia-specific; 3) migration from tissues to lymph nodes; 4) amplification of Ag presentation by monocyte attraction; 5) attraction of naive/resting and activated T cells. Irradiation of leukemic i-DC after CD40L stimulation did not affect their differentiating and functional capacity. Our data indicate that acute myeloid leukemia cells can fully differentiate into functionally competent m-DC and lay the ground for testing their efficacy as a tumor vaccine.

  15. Direct depolarization and antidromic action potentials transiently suppress dendritic IPSPs in hippocampal CA1 pyramidal cells.

    PubMed

    Morishita, W; Alger, B E

    2001-01-01

    Whole-cell current-clamp recordings were made from distal dendrites of rat hippocampal CA1 pyramidal cells. Following depolarization of the dendritic membrane by direct injection of current pulses or by back-propagating action potentials elicited by antidromic stimulation, evoked gamma-aminobutyric acid-A (GABA(A)) receptor-mediated inhibitory postsynaptic potentials (IPSPs) were transiently suppressed. This suppression had properties similar to depolarization-induced suppression of inhibition (DSI): it was enhanced by carbachol, blocked by dendritic hyperpolarization sufficient to prevent action potential invasion, and reduced by 4-aminopyridine (4-AP) application. Thus DSI or a DSI-like process can be recorded in CA1 distal dendrites. Moreover, localized application of TTX to stratum pyramidale blocked somatic action potentials and somatic IPSPs, but not dendritic IPSPs or DSI induced by direct dendritic depolarization, suggesting DSI is expressed in part in the dendrites. These data extend the potential physiological roles of DSI.

  16. Immunostimulatory conventional dendritic cells evolve into regulatory macrophage-like cells.

    PubMed

    Diao, Jun; Mikhailova, Anastassia; Tang, Michael; Gu, Hongtao; Zhao, Jun; Cattral, Mark S

    2012-05-24

    Dendritic cell (DC) homeostasis in peripheral tissues reflect a balance between DC generation, migration, and death. The current model of DC ontogeny indicates that pre-cDCs are committed to become terminal conventional DCs (cDCs). Here, we report the unexpected finding that proliferating immunostimulatory CD11c(+) MHC class II(+) cDCs derived from pre-cDCs can lose their DC identity and generate progeny that exhibit morphologic, phenotypic, and functional characteristics of regulatory macrophages. DC-derived-macrophages (DC-d-Ms) potently suppress T-cell responses through the production of immunosuppressive molecules including nitric oxide, arginase, and IL-10. Relative deficiency of granulocyte-macrophage colony stimulating factor (GM-CSF) provided a permissive signal for DC-d-M generation. Using a transgenic mouse model that allows tracking of CD11c(+) cells in vivo, we found that DC-d-M development occurs commonly in cancer, but not in lymphoid or nonlymphoid tissues under steady-state conditions. We propose that this developmental pathway serves as an alternative mechanism of regulating DC homeostasis during inflammatory processes.

  17. Interleukin-4 Inhibits Regulatory T Cell Differentiation through Regulating CD103+ Dendritic Cells

    PubMed Central

    Tu, Lei; Chen, Jie; Zhang, Hongwei; Duan, Lihua

    2017-01-01

    CD103+ dendritic cells (DCs) have been shown to play a crucial role in the pathogenesis of inflammatory bowel diseases (IBDs) through educating regulatory T (Treg) cells differentiation. However, the mechanism of CD103+ DCs subsets differentiation remains elusive. Interleukin (IL)-4 is a pleiotropic cytokine that is upregulated in certain types of inflammation, including IBDs and especially ulcerative colitis. However, the precise role of IL-4 in the differentiation of CD103+ DCs subpopulation remains unknown. In this study, we observed a repressive role of IL-4 on the CD103+ DCs differentiation in both mouse and human. High-dose IL-4 inhibited the CD103+ DC differentiation. In comparison to CD103− DCs, CD103+ DCs expressed high levels of the co-stimulatory molecules and indoleamine 2,3-dioxygenase (IDO). Interestingly, IL-4 diminished IDO expression on DCs in a dose-dependent manner. Besides, high-dose IL-4-induced bone marrow-derived DCs, and monocyte-derived DCs revealed mature DCs profiles, characterized by increased co-stimulatory molecules and decreased pinocytotic function. Furthermore, DCs generated under low concentrations of IL-4 favored Treg cells differentiation, which depend on IDO produced by CD103+ DCs. Consistently, IL-4 also reduced the frequency of CD103+ DC in vivo. Thus, we here demonstrated that the cytokine IL-4 involved in certain types of inflammatory diseases by orchestrating the functional phenotype of CD103+ DCs subsets. PMID:28316599

  18. Redefining the role of dendritic cells in periodontics.

    PubMed

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

    2013-11-01

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

  19. Targeting MOG expression to dendritic cells delays onset of experimental autoimmune disease.

    PubMed

    Ko, Hyun-Ja; Chung, Jie-Yu; Nasa, Zeyad; Chan, James; Siatskas, Christopher; Toh, Ban-Hock; Alderuccio, Frank

    2011-05-01

    Haematopoietic stem cell (HSC) transfer coupled with gene therapy is a powerful approach to treating fatal diseases such as X-linked severe combined immunodeficiency. This ability to isolate and genetically manipulate HSCs also offers a strategy for inducing immune tolerance through ectopic expression of autoantigens. We have previously shown that retroviral transduction of bone marrow (BM) with vectors encoding the autoantigen, myelin oligodendrocyte glycoprotein (MOG), can prevent the induction of experimental autoimmune encephalomyelitis (EAE). However, ubiquitous cellular expression of autoantigen driven by retroviral promoters may not be the best approach for clinical translation and a targeted expression approach may be more acceptable. As BM-derived dendritic cells (DCs) play a major role in tolerance induction, we asked whether targeted expression of MOG, a target autoantigen in EAE, to DCs can promote tolerance induction and influence the development of EAE. Self-inactivating retroviral vectors incorporating the mouse CD11c promoter were generated and used to transduce mouse BM cells. Transplantation of gene-modified cells into irradiated recipients resulted in the generation of chimeric mice with transgene expression limited to DCs. Notably, chimeric mice transplanted with MOG-expressing BM cells manifest a significant delay in the development of EAE suggesting that targeted antigen expression to tolerogenic cell types may be a feasible approach to inducing antigen-specific tolerance.

  20. Ablation of ErbB4 from excitatory neurons leads to reduced dendritic spine density in mouse prefrontal cortex

    PubMed Central

    Cooper, Margaret A.; Koleske, Anthony J.

    2014-01-01

    Dendritic spine loss is observed in many psychiatric disorders, including schizophrenia, and likely contributes to the altered sense of reality, disruption of working memory, and attention deficits that characterize these disorders. ErbB4, a member of the EGF family of receptor tyrosine kinases, is genetically associated0020with schizophrenia, suggesting that alterations in ErbB4 function contribute to the disease pathology. Additionally, ErbB4 functions in synaptic plasticity, leading us to hypothesize that disruption of ErbB4 signaling may affect dendritic spine development. We show that dendritic spine density is reduced in the dorsomedial prefrontal cortex of ErbB4 conditional whole-brain knockout mice. We find that ErbB4 localizes to dendritic spines of excitatory neurons in cortical neuronal cultures and is present in synaptic plasma membrane preparations. Finally, we demonstrate that selective ablation of ErbB4 from excitatory neurons leads to a decrease in the proportion of mature spines and an overall reduction in dendritic spine density in the prefrontal cortex of weanling (P21) mice that persists at 2 months of age. These results suggest that ErbB4 signaling in excitatory pyramidal cells is critical for the proper formation and maintenance of dendritic spines in excitatory pyramidal cells. PMID:24752666

  1. Investigating Evolutionary Conservation of Dendritic Cell Subset Identity and Functions

    PubMed Central

    Vu Manh, Thien-Phong; Bertho, Nicolas; Hosmalin, Anne; Schwartz-Cornil, Isabelle; Dalod, Marc

    2015-01-01

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

  2. 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

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

    NASA Technical Reports Server (NTRS)

    Rohatgi, A.

    1980-01-01

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

  4. Building on Dendritic Cell Subsets to Improve Cancer Vaccines

    PubMed Central

    Palucka, Karolina; Ueno, Hideki; Zurawski, Gerard; Fay, Joseph; Banchereau, Jacques

    2010-01-01

    SUMMARY T cells can reject established tumors when adoptively transferred into patients, thereby demonstrating that the immune system can be harnessed for cancer therapy. However, such passive immunotherapy is unlikely to maintain memory T cells that might control tumor outgrowth on the long term. Active immunotherapy with vaccines has the potential to induce tumor-specific effector and memory T cells. Vaccines act through dendritic cells (DCs) which induce, regulate and maintain T cell immunity. Clinical trials testing first generation DC vaccines pulsed with tumor antigens provided a proof-of-principle that therapeutic immunity can be elicited. The increased knowledge of the DC system, including the existence of distinct DC subsets is leading to new trials which aim at improved immune and clinical outcomes. PMID:20226644

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

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

    PubMed

    Kumar, Chaitanya; Kohli, Sakshi; Bapsy, Poonamalle Parthasarathy; Vaid, Ashok Kumar; Jain, Minish; Attili, Venkata Sathya Suresh; Sharan, Bandana

    2017-03-01

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

  7. Regulation of intestinal immune system by dendritic cells.

    PubMed

    Ko, Hyun-Jeong; Chang, Sun-Young

    2015-02-01

    Innate immune cells survey antigenic materials beneath our body surfaces and provide a front-line response to internal and external danger signals. Dendritic cells (DCs), a subset of innate immune cells, are critical sentinels that perform multiple roles in immune responses, from acting as principal modulators to priming an adaptive immune response through antigen-specific signaling. In the gut, DCs meet exogenous, non-harmful food antigens as well as vast commensal microbes under steady-state conditions. In other instances, they must combat pathogenic microbes to prevent infections. In this review, we focus on the function of intestinal DCs in maintaining intestinal immune homeostasis. Specifically, we describe how intestinal DCs affect IgA production from B cells and influence the generation of unique subsets of T cell.

  8. Integrin-mediated interactions between B cells and follicular dendritic cells influence germinal center B cell fitness1

    PubMed Central

    Wang, Xiaoming; Rodda, Lauren; Bannard, Oliver; Cyster, Jason G.

    2014-01-01

    Integrin-ligand interactions between germinal center (GC) B cells and antigen-presenting follicular dendritic cells (FDCs) have been suggested to play central roles during GC responses but their in vivo requirement has not been directly tested. Here we show that while integrins αLβ2 and α4β1 are highly expressed and functional on mouse GC B cells, removal of single integrins or their ligands had little effect on B cell participation in the GC response. Combined β2-integrin deficiency and α4-integrin blockade also did not affect the GC response against a particulate antigen. However, the combined integrin deficiency did cause B cells to be outcompeted in splenic GC responses against a soluble protein antigen and in mesenteric lymph node GC responses against gut-derived antigens. Similar findings were made for β2-deficient B cells in mice lacking VCAM1 on FDCs. The reduced fitness of the GC B cells did not appear to be due to decreased antigen acquisition, proliferation rates or pAKT levels. In summary, our findings provide evidence that αLβ2 and α4β1 play overlapping and context-dependent roles in supporting interactions with FDCs that can augment the fitness of responding GC B cells. We also find that mouse GC B cells upregulate αvβ3 and adhere to vitronectin and milk fat globule EGF-factor-8 protein. Integrin β3-deficient B cells contributed in a slightly exaggerated manner to GC responses suggesting this integrin has a regulatory function in GC B cells. PMID:24740506

  9. Methods of analysis of dendritic cell-derived exosome-shuttle microRNA and its horizontal propagation between dendritic cells.

    PubMed

    Montecalvo, Angela; Larregina, Adriana T; Morelli, Adrian E

    2013-01-01

    Exosomes are extremely small (<100 nm) membrane vesicles, generated in the endocytic compartment that are released to the extracellular milieu by living cells. Although the biological function of exosomes in vivo remains unclear, they seem to function as mechanisms of cell-to-cell communication for horizontal transfer of proteins, antigens, prions, morphogens, mRNA, and noncoding regulatory RNAs, including microRNAs (miRNAs) (also known as exosome-shuttle miRNAs). Dendritic cells (DCs), the most potent professional antigen-presenting leukocytes of the immune system, release relatively high levels of exosomes and also interact with free exosomes present in the extracellular space. Therefore, DCs constitute a good model for the analysis of exosome-shuttle miRNAs and their horizontal propagation between cells. This chapter provides basic protocols for purification of exosomes released by mouse bone marrow-derived DCs, analysis of their miRNA content, and assessment of the function of exosome-shuttle miRNAs, once they are transferred to target/acceptor DCs.

  10. Dendritic Cell Regulation by Cannabinoid-Based Drugs

    PubMed Central

    Svensson, Mattias; Chen, Puran; Hammarfjord, Oscar

    2010-01-01

    Cannabinoid pharmacology has made important advances in recent years after the cannabinoid system was discovered. Studies in experimental models and in humans have produced promising results using cannabinoid-based drugs for the treatment of obesity and cancer, as well as neuroinflammatory and chronic inflammatory diseases. Moreover, as we discuss here, additional studies also indicates that these drugs have immunosuppressive and anti-inflammatory properties including modulation of immune cell function. Thus, manipulation of the endocannabinoid system in vivo may provide novel therapeutic strategies against inflammatory disorders. At least two types of cannabinoid receptors, cannabinoid 1 and cannabinoid 2 receptors are expressed on immune cells such as dendritic cells (DC). Dendritic cells are recognized for their critical role in initiating and maintaining immune responses. Therefore, DC are potential targets for cannabinoid-mediated modulation. Here, we review the effects of cannabinoids on DC and provide some perspective concerning the therapeutic potential of cannabinoids for the treatment of human diseases involving aberrant inflammatory processes. PMID:27713374

  11. Resistivity and thickness effects in dendritic web silicon solar cells

    NASA Technical Reports Server (NTRS)

    Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

    1987-01-01

    The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

  12. Plasmacytoid dendritic cells play a major role in apoptotic leukocyte-induced immune modulation.

    PubMed

    Bonnefoy, Francis; Perruche, Sylvain; Couturier, Mélanie; Sedrati, Abdeslem; Sun, Yunwei; Tiberghien, Pierre; Gaugler, Béatrice; Saas, Philippe

    2011-05-15

    Several APCs participate in apoptotic cell-induced immune modulation. Whether plasmacytoid dendritic cells (PDCs) are involved in this process has not yet been characterized. Using a mouse model of allogeneic bone marrow engraftment, we demonstrated that donor bone marrow PDCs are required for both donor apoptotic cell-induced engraftment and regulatory T cell (Treg) increase. We confirmed in naive mice receiving i.v. syngeneic apoptotic cell infusion that PDCs from the spleen induce ex vivo Treg commitment. We showed that PDCs did not interact directly with apoptotic cells. In contrast, in vivo macrophage depletion experiments using clodronate-loaded liposome infusion and coculture experiments with supernatant from macrophages incubated with apoptotic cells showed that PDCs required macrophage-derived soluble factors--including TGF-β--to exert their immunomodulatory functions. Overall, PDCs may be considered as the major APC involved in Treg stimulation/generation in the setting of an immunosuppressive environment obtained by apoptotic cell infusion. These findings show that like other APCs, PDC functions are influenced, at least indirectly, by exposure to blood-borne apoptotic cells. This might correspond with an additional mechanism preventing unwanted immune responses against self-antigens clustered at the cell surface of apoptotic cells occurring during normal cell turnover.

  13. p15Ink4b is Key in Dendritic Cell Development | Center for Cancer Research

    Cancer.gov

    An important step in the initiation of leukemia is the ability of pre-leukemic and leukemic cells to evade the immune system. Dendritic cells are instrumental in maintaining the body’s immunity, and CCR scientists have shown for the first time that the tumor suppressor protein p15Ink4b regulates the differentiation and maturation of conventional dendritic cells.

  14. Virulent Salmonella enterica Serovar Typhimurium Evades Adaptive Immunity by Preventing Dendritic Cells from Activating T Cells

    PubMed Central

    Tobar, Jaime A.; Carreño, Leandro J.; Bueno, Susan M.; González, Pablo A.; Mora, Jorge E.; Quezada, Sergio A.; Kalergis, Alexis M.

    2006-01-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis. PMID:17057096

  15. Allogeneic IgG combined with dendritic cell stimuli induces anti-tumor T cell immunity

    PubMed Central

    Carmi, Yaron; Spitzer, Matthew H.; Linde, Ian L.; Burt, Bryan M; Prestwood, Tyler R.; Perlman, Nikola; Davidson, Matthew G.; Kenkel, Justin A.; Segal, Ehud; Pusapati, Ganesh V.; Bhattacharya, Nupur; Engleman, Edgar G.

    2015-01-01

    While cancers grow in their hosts and evade host immunity through immunoediting and immunosuppression1–5, tumors are rarely transmissible between individuals. Much like transplanted allogeneic organs, allogeneic tumors are reliably rejected by host T cells, even when the tumor and host share the same major histocompatibility complex (MHC) alleles, the most potent determinants of transplant rejection6–10. How such tumor-eradicating immunity is initiated remains unknown, though elucidating this process could provide a roadmap for inducing similar responses against naturally arising tumors. We found that allogeneic tumor rejection is initiated by naturally occurring tumor-binding IgG antibodies, which enable dendritic cells (DC) to internalize tumor antigens and subsequently activate tumor-reactive T cells. We exploited this mechanism to successfully treat autologous and autochthonous tumors. Either systemic administration of DC loaded with allogeneic IgG (alloIgG)-coated tumor cells or intratumoral injection of alloIgG in combination with DC stimuli induced potent T cell mediated anti-tumor immune responses, resulting in tumor eradication in mouse models of melanoma, pancreas, lung and breast cancer. Moreover, this strategy led to eradication of distant tumors and metastases, as well as the injected primary tumors. To assess the clinical relevance of these findings, we studied antibodies and cells from patients with lung cancer. T cells from these patients responded vigorously to autologous tumor antigens after culture with alloIgG-loaded DC, recapitulating our findings in mice. These results reveal that tumor-binding alloIgG can induce powerful anti-tumor immunity that can be exploited for cancer immunotherapy. PMID:25924063

  16. Aggressive Indeterminate Dendritic Cell Tumor Mimicking Scalp Angiosarcoma.

    PubMed

    Li, Yun; Wang, Ting-Ting; Zhang, Zi-Hui; Wang, Lin

    2017-10-01

    Indeterminate dendritic cell tumor (IDCT) is a proliferation of CD1a+, S100+ and langerin- histiocytes with a generally benign course. Here, we describe a case of a 90-year-old male who developed skin lesions on his scalp mimicking angiosarcoma and lymphadenopathy. He died six months after the onset of skin lesions despite of months' radiotherapy. Pathological examination ruled out scalp angiosarcoma and showed a high Ki-67 index. The appearance of skin lesions and lymphadenopathy led to challenges in diagnosis and the development of a treatment plan.

  17. Differential distribution of NCX1 contributes to spine–dendrite compartmentalization in CA1 pyramidal cells

    PubMed Central

    Lőrincz, Andrea; Rózsa, Balázs; Katona, Gergely; Vizi, E. Sylvester; Tamás, Gábor

    2007-01-01

    Compartmentalization of Ca2+ between dendritic spines and shafts is governed by diffusion barriers and a range of Ca2+ extrusion mechanisms. The distinct contribution of different Ca2+ clearance systems to Ca2+ compartmentalization in dendritic spines versus shafts remains elusive. We applied a combination of ultrastructural and functional imaging methods to assess the subcellular distribution and role of NCX1 in rat CA1 pyramidal cells. Quantitative electron microscopic analysis of preembedding immunogold reactions revealed uniform densities of NCX1 along the shafts of apical and basal dendrites, but densities in dendritic shafts were approximately seven times higher than in dendritic spines. In line with these results, two-photon imaging of synaptically activated Ca2+ transients during NCX blockade showed preferential action localized to the dendritic shafts for NCXs in regulating spine–dendrite coupling. PMID:17215351

  18. Replication of human immunodeficiency virus type 1 in primary dendritic cell cultures.

    PubMed Central

    Langhoff, E; Terwilliger, E F; Bos, H J; Kalland, K H; Poznansky, M C; Bacon, O M; Haseltine, W A

    1991-01-01

    The ability of the human immunodeficiency virus type 1 (HIV-1) to replicate in primary blood dendritic cells was investigated. Dendritic cells compose less than 1% of the circulating leukocytes and are nondividing cells. Highly purified preparations of dendritic cells were obtained using recent advances in cell fractionation. The results of these experiments show that dendritic cells, in contrast to monocytes and T cells, support the active replication of all strains of HIV-1 tested, including T-cell tropic and monocyte/macrophage tropic isolates. The dendritic cell cultures supported much more virus production than did cultures of primary unseparated T cells, CD4+ T cells, and adherent as well as nonadherent monocytes. Replication of HIV-1 in dendritic cells produces no noticeable cytopathic effect nor does it decrease total cell number. The ability of the nonreplicating dendritic cells to support high levels of replication of HIV-1 suggests that this antigen-presenting cell population, which is also capable of supporting clonal T-cell growth, may play a central role in HIV pathogenesis, serving as a source of continued infection of CD4+ T cells and as a reservoir of virus infection. Images PMID:1910172

  19. 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.

  20. Innate immune sensing of HIV-1 by dendritic cells.

    PubMed

    Luban, Jeremy

    2012-10-18

    HIV-1-specific antibodies and CD8(+) cytotoxic T cells are detected in most HIV-1-infected people, yet HIV-1 infection is not eradicated. Contributing to the failure to mount a sterilizing immune response may be the inability of antigen-presenting dendritic cells (DCs) to sense HIV-1 during acute infection, and thus the inability to effectively prime naive, HIV-1-specific T cells. Recent findings related to DC-expressed innate immune factors including SAMHD1, TREX1, and TRIM5 provide a molecular basis for understanding why DCs fail to adequately sense invasion by this deadly pathogen and suggest experimental approaches to improve T cell priming to HIV-1 in prophylactic vaccination protocols. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. [Features of functional activity of dendritic cells in tumor growth].

    PubMed

    Sennikov, S V; Obleukhova, I A; Kurilin, V V; Kulikova, E V; Khristin, A A

    2015-01-01

    During recent years much data, accumulated on biology, function and role of dendritic cells (DC) in cancer development, in a new way allow assessing their role in disease process. Identification of features of DC functional state as well as their interaction and influence on the immune cells in tumor growth can be used as a basis for a new approach to cancer therapy enhancing standard therapy efficacy. The review analyzes different mechanisms of escaping of tumor cell from immune surveillance involving DC as one of the main participants of antitumor immune response. Also the prospects of using DC for vaccination are discussed. DC can be promising target for therapeutic strategies and also can be used for formation of antitumor response and cell therapy.

  2. Innate NKT lymphocytes confer superior adaptive immunity via tumor-capturing dendritic cells.

    PubMed

    Liu, Kang; Idoyaga, Juliana; Charalambous, Anna; Fujii, Shin-Ichiro; Bonito, Anthony; Mordoh, Jose; Wainstok, Rosa; Bai, Xue-Feng; Liu, Yang; Steinman, Ralph M

    2005-12-05

    If irradiated tumor cells could be rendered immunogenic, they would provide a safe, broad, and patient-specific array of antigens for immunotherapies. Prior approaches have emphasized genetic transduction of live tumor cells to express cytokines, costimulators, and surrogate foreign antigens. We asked if immunity could be achieved by delivering irradiated, major histocompatibility complex-negative plasmacytoma cells to maturing mouse dendritic cells (DCs) within lymphoid organs. Tumor cells injected intravenously (i.v.) were captured by splenic DCs, whereas subcutaneous (s.c.) injection led only to weak uptake in lymph node or spleen. The natural killer T (NKT) cells mobilizing glycolipid alpha-galactosyl ceramide, used to mature splenic DCs, served as an effective adjuvant to induce protective immunity. This adjuvant function was mimicked by a combination of poly IC and agonistic alphaCD40 antibody. The adjuvant glycolipid had to be coadministered with tumor cells i.v. rather than s.c. Specific resistance was generated both to a plasmacytoma and lymphoma. The resistance afforded by a single vaccination lasted >2 mo and required both CD4+ and CD8+ T cells. Mature tumor capturing DCs stimulated the differentiation of P1A tumor antigen-specific, CD8+ T cells and uniquely transferred tumor resistance to naive mice. Therefore, the access of dying tumor cells to DCs that are maturing to activated NKT cells efficiently induces long-lived adaptive resistance.

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

    PubMed

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

    2015-02-01

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

  4. NGF induces neonatal rat sensory neurons to extend dendrites in culture after removal of satellite cells.

    PubMed

    De Koninck, P; Carbonetto, S; Cooper, E

    1993-02-01

    Vertebrate sensory neurons have a pseudo-unipolar morphology; their somata are covered by satellite cells and lack dendrites or synaptic contacts. However, when neonatal rat sensory neurons from the nodose ganglia develop in culture in absence of satellite cells and with NGF, they form synapses among themselves. In this study, we investigated whether neonatal rat nodose neurons express dendrites under the same culture conditions. We show by Lucifer yellow injection that nodose neurons remain typically unipolar when cocultured with their ganglionic satellite cells. However, when these neurons are cultured without satellite cells, virtually all neurons acquire a multipolar morphology. Moreover, when NGF is added to satellite cell-free cultures, several neurons extend dendrites; these processes stain positively for microtubule-associated protein-2. NGF induces a 17-fold increase in dendritic outgrowth after 3 weeks but has little effect on axon number. In addition, we find that the ability of nodose neurons to extend dendrites is developmentally regulated. Furthermore, in a combined morphological and electrophysiological study, using whole-cell voltage-clamp technique with Lucifer yellow in the recording solution, we demonstrate a positive correlation between the extent of dendritic outgrowth and the density of ACh currents, suggesting that these dendrites have ACh receptors. Our results indicate that neonatal rat nodose neurons are capable of extending dendrites and that extrinsic factors can induce or suppress their extension. In addition, the results suggest that these dendrites may act as principal post-synaptic structures for synapse formation that occurs in these cultures.

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  6. [In vitro culture of human dendritic cells by using a HydroCell™].

    PubMed

    Aruga, Atsushi; Kogen, Yumi; Sakai, Mayuko; Kotera, Yoshihito; Yamamoto, Masakazu

    2011-11-01

    Cancer Immunotherapy using dendritic cells would be a feasible and useful tool for cancer treatment. However, no immunotherapy has been approved in Japan because of a lack of any randomized clinical studies. We are now trying to develop an automatic dendritic cell culture system in order to perform a large-scale randomized clinical trial. In this study, we investigated the utility of a HydroCell™ for in vitro culture of human dendritic cells induced from peripheral blood monocytes. The dendritic cells grew one and a half times when they were cultured in a HydroCell™. All the cells were floating and harvested easily without any enzymes. The cells expressed the CD80 and CD83 molecules on their surface and still had strong phagocytosis. This results demonstrated that a HydroCell™ was a useful tool for in vitro culture of dendritic cells.

  7. Tolerogenic and Activatory Plasmacytoid Dendritic Cells in Autoimmunity

    PubMed Central

    Guéry, Leslie; Hugues, Stéphanie

    2013-01-01

    Plasmacytoid dendritic cells (pDCs) are a particular subset of DCs that link innate and adaptive immunity. They are responsible for the substantial production of type 1 interferon (IFN-I) in response to viral RNA or DNA through activation of TLR7 and 9. Furthermore, pDCs present antigens (Ag) and induce naïve T cell differentiation. It has been demonstrated that pDCs can induce immunogenic T cell responses through differentiation of cytotoxic CD8+ T cells and effector CD4+ T cells. Conversely, pDCs exhibit strong tolerogenic functions by inducing CD8+ T cell deletion, CD4+ T cell anergy, and Treg differentiation. However, since IFN-I produced by pDCs efficiently activates and recruits conventional DCs, B cells, T cells, and NK cells, pDCs also indirectly affect the nature and the amplitude of adaptive immune responses. As a consequence, the precise role of Ag-presenting functions of pDCs in adaptive immunity has been difficult to dissect in vivo. Additionally, different experimental procedures led to conflicting results regarding the outcome of T cell responses induced by pDCs. During the development of autoimmunity, pDCs have been shown to play both immunogenic and tolerogenic functions depending on disease, disease progression, and the experimental conditions. In this review, we will discuss the relative contribution of innate and adaptive pDC functions in modulating T cell responses, particularly during the development of autoimmunity. PMID:23508732

  8. Impact of TRPV3 on the development of allergic dermatitis as a dendritic cell modulator.

    PubMed

    Yamamoto-Kasai, Erika; Yasui, Kiyoshi; Shichijo, Michitaka; Sakata, Tsuneaki; Yoshioka, Takeshi

    2013-12-01

    The transient receptor potential channel vanilloid subfamily V member 3 (TRPV3), which functions as a thermosensor in keratinocytes, plays an important role in the development of allergic and itchy dermatitis in rodents. Although real-time PCR analysis using lesional and non-lesional skin samples from patients with atopic dermatitis showed that TRPV3 was expressed in lesional skin, the role that TRPV3 plays in patients with dermatitis is still relatively obscure. Here, we determined whether TRPV3 was a dendritic cell (DC) modulator using DS-Nh mice with a gain-of-function mutation in TRPV3 (TRPV3Gly573Ser), because increasing skin temperature is associated with the modulation of dermal dendritic cells (DCs). Interestingly, increased responses to haptens by skin and DCs were observed in DS-Nh mice compared with those from DS mice with wild-type TRPV3. Increased thymic stromal lymphopoietin (TSLP) responses were also observed in keratinocytes from DS-Nh mice compared with those from DS mice. Taken together, we propose that the DS-Nh mouse is a good model to use in order to better understand the role of this orphan channel and that TRPV3 may represent a new therapeutic target in certain types of dermatitis through the control of DCs.

  9. Activity-dependent accumulation of calcium in Purkinje cell dendritic spines

    SciTech Connect

    Andrews, S.B.; Leapman, R.D.; Landis, D.M.; Reese, T.S.

    1988-03-01

    The calcium content of synapses of parallel fibers on Purkinje cell dendritic spines was determined by electron probe x-ray microanalysis of freeze-dried cryosections from directly frozen slices of mouse cerebellar cortex. In fresh slices frozen within 20-30 sec of excision, calcium concentrations ranging from 0.8 to 18.6 mmol/kg of dry weight were measured in cisterns of smooth endoplasmic reticulum within Purkinje cell dendritic spines. The average calcium content of spine cisterns in rapidly excised slices (6.7 +/- 0.6 mmol/kg of dry weight +/- SEM) was higher than the average calcium content of spine cisterns in brain slices incubated without stimulation for 1-2 hr before direct freezing (2.5 +/- 0.4 mmol/kg of dry weight). Depolarization of incubated cerebellar slices by isotonic 55 mM KCl resulted in the accumulation within spine cisterns of very high amounts of calcium or isotonically substituted strontium, both derived from the extracellular fluid. These results suggest that one function of spine cisterns is to sequester free calcium that enters the spine through ligand-gated or voltage-gated channels during synaptic transmission.

  10. Neural stem cell transplantation in mouse brain.

    PubMed

    Lee, Jean-Pyo; McKercher, Scott; Muller, Franz-Josef; Snyder, Evan Y

    2008-01-01

    Neural stem cells (NSCs) are the most primordial, least committed cells of the nervous system, and transplantation of these multipotent cells holds the promise of regenerative therapy for many central nervous system (CNS) diseases. This unit describes methods for NSC transplantation into neonatal mouse pups, embryonic mouse brain, and adult mouse brain. A description of options for detection of labeled donor cells in engrafted mouse brain is provided along with an example protocol for detecting lacZ-expressing cells in situ. Also included is a protocol for preparing NSCs for transplantation.

  11. Immunohistochemical detection of dendritic cell markers in cattle.

    PubMed

    Romero-Palomo, F; Risalde, M A; Molina, V; Sánchez-Cordón, P J; Pedrera, M; Gómez-Villamandos, J C

    2013-11-01

    Dendritic cells (DCs) are "professional" antigen-presenting cells with a critical role in the regulation of innate and adaptive immune responses and thus have been considered of great interest in the study of a variety of infectious diseases. The objective of this investigation was to characterize the in vivo distribution of DCs in bovine tissues by using potential DC markers to establish a basis for the study of DCs in diseased tissues. Markers evaluated included MHCII, CD208, CD1b, CD205, CNA.42, and S100 protein, the latter 2 being expressed by follicular dendritic cells whose origin and role are different from the rest of hematopoietic DCs. Paraffin wax-embedded tissues from 6 healthy Friesian calves were subjected to the avidin-biotin-peroxidase method, and the most appropriate fixatives, dilutions, and antigen retrieval pretreatments were studied for each of the primary antibodies. The most significant results included the localization of CD208-positive cells not only in the T zone of lymphoid organs but also within lymphoid follicles; CD1b-positive cells were mainly found in thymus and interfollicular areas of some lymph nodes; cells stained with anti-CD205 antibody were scarce, and their location was mainly in nonlymphoid tissues; and CNA.42- and S100 protein-positive cells localized in primary lymphoid follicles and light zones of germinal centers, although showing differences in the staining pattern. Furthermore, MHCII was established as one of the most sensitive markers for any DC of hematopoietic origin. These results increase our understanding of DC immunolabeling and will help in future DC studies of both healthy and diseased tissues.

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

    PubMed

    Pazmandi, Kitti; Kumar, Brahma V; Szabo, Krisztina; Boldogh, Istvan; Szoor, Arpad; Vereb, Gyorgy; Veres, Agota; Lanyi, Arpad; Rajnavolgyi, Eva; Bacsi, Attila

    2012-01-01

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

  13. Ragweed Subpollen Particles of Respirable Size Activate Human Dendritic Cells

    PubMed Central

    Pazmandi, Kitti; Kumar, Brahma V.; Szabo, Krisztina; Boldogh, Istvan; Szoor, Arpad; Vereb, Gyorgy; Veres, Agota; Lanyi, Arpad; Rajnavolgyi, Eva; Bacsi, Attila

    2012-01-01

    Ragweed (Ambrosia artemisiifolia) pollen grains, which are generally considered too large to reach the lower respiratory tract, release subpollen particles (SPPs) of respirable size upon hydration. These SPPs contain allergenic proteins and functional NAD(P)H oxidases. In this study, we examined whether exposure to SPPs initiates the activation of human monocyte-derived dendritic cells (moDCs). We found that treatment with freshly isolated ragweed SPPs increased the intracellular levels of reactive oxygen species (ROS) in moDCs. Phagocytosis of SPPs by moDCs, as demonstrated by confocal laser-scanning microscopy, led to an up-regulation of the cell surface expression of CD40, CD80, CD86, and HLA-DQ and an increase in the production of IL-6, TNF-α, IL-8, and IL-10. Furthermore, SPP-treated moDCs had an increased capacity to stimulate the proliferation of naïve T cells. Co-culture of SPP-treated moDCs with allogeneic CD3+ pan-T cells resulted in increased secretion of IFN-γ and IL-17 by T cells of both allergic and non-allergic subjects, but induced the production of IL-4 exclusively from the T cells of allergic individuals. Addition of exogenous NADPH further increased, while heat-inactivation or pre-treatment with diphenyleneiodonium (DPI), an inhibitor of NADPH oxidases, strongly diminished, the ability of SPPs to induce phenotypic and functional changes in moDCs, indicating that these processes were mediated, at least partly, by the intrinsic NAD(P)H oxidase activity of SPPs. Collectively, our data suggest that inhaled ragweed SPPs are fully capable of activating dendritic cells (DCs) in the airways and SPPs' NAD(P)H oxidase activity is involved in initiation of adaptive immune responses against innocuous pollen proteins. PMID:23251688

  14. Dendritic-tumor fusion cells in cancer immunotherapy.

    PubMed

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

    2015-03-01

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

  15. Dendritic cell specific targeting of MyD88 signalling pathways in vivo.

    PubMed

    Arnold-Schrauf, Catharina; Berod, Luciana; Sparwasser, Tim

    2015-01-01

    Dendritic cells (DCs) are key regulators of both innate and adaptive immunity. During infection, DCs recognise pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs) including the Toll-like receptor (TLR) family. TLRs mainly signal via the adaptor protein MyD88. This signalling pathway is required for immune protection during many infections, which are lethal in the absence of MyD88. However, the cell type specific importance of this pathway during both innate and adaptive immune responses against pathogens in vivo remains ill-defined. We discuss recent findings from conditional KO or gain-of-function mouse models targeting TLR/MyD88 signalling pathways in DCs and other myeloid cells during infection. While the general assumption that MyD88-dependent recognition by DCs is essential for inducing protective immunity holds true in some instances, the results surprisingly indicate a much more complex context-dependent requirement for this pathway in DCs and other myeloid or lymphoid cell-types in vivo. Furthermore, we highlight the advantages of Cre-mediated DC targeting approaches and their possible limitations. We also present future perspectives on the development of new genetic mouse models to target distinct DC subsets in vivo. Such models will serve to understand the functional heterogeneity of DCs in vivo.

  16. Maturation modulates caspase-1-independent responses of dendritic cells to Anthrax lethal toxin.

    PubMed

    Reig, Núria; Jiang, Aimin; Couture, Rachael; Sutterwala, Fayyaz S; Ogura, Yasunori; Flavell, Richard A; Mellman, Ira; van der Goot, F Gisou

    2008-05-01

    Anthrax lethal toxin (LT) contributes to the immune evasion strategy of Bacillus anthracis by impairing the function of cells of the immune system, such as macrophages and dendritic cells (DCs). Macrophages from certain inbred mice strains undergo rapid death upon LT treatment mediated by caspase-1 activation dependent on Nalp1b, an inflammasome component. Rapid LT-induced death is however, not observed in macrophages from human and many mouse strains. Here, we focused on the responses of various murine DCs to LT. Using a variety of knockout mice, we found that depending on the mouse strain, death of bone marrow-derived DCs and macrophages was mediated either by a fast Nalp1b and caspase-1-dependent, or by a slow caspase-1-independent pathway that was triggered by the impairment of MEK1/2 pathways. Caspase-1-independent death was observed in cells of different genetic backgrounds and interestingly occurred only in immature DCs. Maturation, triggered by different types of stimuli, led to full protection of DCs. These studies illustrate that the cellular damage inflicted by LT depends not only on the innate responses but also on the maturation stage of the cell, which modulates the more general caspase-1-independent responses.

  17. Maturation Modulates Caspase-1 Independent Responses of Dendritic Cells to Anthrax Lethal Toxin

    PubMed Central

    Reig, Núria; Jiang, Aimin; Couture, Rachael; Sutterwala, Fayyaz S.; Ogura, Yasunori; Flavell, Richard A.; Mellman, Ira; van der Goot, F. Gisou

    2010-01-01

    Anthrax lethal toxin (LT) contributes to the immune evasion strategy of B. anthracis by impairing the function of cells of the immune system, such as macrophages and dendritic cells (DCs). Macrophages from certain inbred mice strains undergo rapid death upon LT treatment mediated by caspase-1 activation dependent on Nalp1b, an inflammasome component. Rapid LT-induced death is however not observed in macrophages from human and many mouse strains. Here, we focused on the responses of various murine DCs to LT. Using a variety of knock-out mice, we found that depending on the mouse strain, death of bone marrow derived DCs and macrophages was mediated either by a fast Nalp1b and caspase-1 dependent, or by a slow caspase-1 independent pathway that was triggered by the impairment of MEK1/2 pathways. Caspase-1 independent death was observed in cells of different genetic backgrounds and interestingly occurred only in immature DCs. Maturation, triggered by different types of stimuli, led to full protection of DCs. These studies illustrate that the cellular damage inflicted by LT depends not only on the innate responses but also on the maturation stage of the cell, which modulates the more general caspase-1 independent responses. PMID:18194483

  18. Interaction of Salmonella enterica Serotype Typhimurium with Dendritic Cells Is Defined by Targeting to Compartments Lacking Lysosomal Membrane Glycoproteins

    PubMed Central

    García-Del Portillo, Francisco; Jungnitz, Heidrun; Rohde, Manfred; Guzmán, Carlos A.

    2000-01-01

    Dendritic cells (DCs) play a central role in the generation of acquired immunity to infections by pathogenic microorganisms. Salmonella enterica serotype Typhimurium is known to survive and proliferate intracellularly within macrophages and nonphagocytic cells, but no data exist on how this pathogen interacts with DCs. In this report, we show the capacity of serotype Typhimurium to survive within the established mouse DC line CB1. In contrast to the case for the macrophage model, the compartments of DCs containing serotype Typhimurium are devoid of lysosomal membrane glycoproteins and the PhoPQ two-component regulatory system is not essential for pathogen intracellular survival. PMID:10768999

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

    PubMed

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

    2017-07-07

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

  20. Aligning bona fide dendritic cell populations across species.

    PubMed

    Dutertre, Charles-Antoine; Wang, Lin-Fa; Ginhoux, Florent

    2014-01-01

    Dendritic cells (DC) are professional antigen sensing and presenting cells that link innate and adaptive immunity. Consisting of functionally specialized subsets, they form a complex cellular network capable of integrating multiple environmental signals leading to immunity or tolerance. Much of DC research so far has been carried out in mice and increasing efforts are now being devoted to translating the findings into humans and other species. Recent studies have aligned these cellular networks across species at multiple levels from phenotype, gene expression program, ontogeny and functional specializations. In this review, we focus on recent advances in the definition of bona fide DC subsets across species. The understanding of functional similarities and differences of specific DC subsets in different animals not only brings light in the field of DC biology, but also paves the way for the design of future effective therapeutic strategies targeting these cells.

  1. Dendritic cells in autoimmune disorders and cancer of the thyroid.

    PubMed

    Lewinski, Andrzej; Sliwka, Przemyslaw Wiktor; Stasiolek, Mariusz

    2014-01-01

    Dendritic cells (DCs), considered as one of the crucial immune regulatory populations, are implicated in the immune pathology of various disorders. Also in the thyroid gland, DCs were shown to be involved in early and chronic phases of various types of autoimmunity - including Hashimoto's thyroiditis and Graves' disease. In thyroid malignant processes, DCs are suggested as an important element of both tumour defence and tumour immune evasion mechanisms. Recent findings emphasize a crucial role of interactions between particular DC subsets and other regulatory cell populations (e.g. FoxP3+ regulatory T cells) in thyroid pathology. Additionally, an increasing attention has been paid to the control of DC function by thyrometabolic conditions.

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

    PubMed

    Heesters, Balthasar A; Lindqvist, Madelene; Vagefi, Parsia A; Scully, Eileen P; Schildberg, Frank A; Altfeld, Marcus; Walker, Bruce D; Kaufmann, Daniel E; Carroll, Michael C

    2015-12-01

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

  3. Role of plasmacytoid dendritic cells in lung-associated inflammation.

    PubMed

    Sorrentino, Rosalinda; Morello, Silvana; Pinto, Aldo

    2010-06-01

    Plasmacytoid Dendritic Cells (pDCs) are important immune orchestrators. One of the most important features of pDCs is the high production of IFN type I that can promote the polarization of T cells towards a Th1 phenotype. Recent evidence has highlighted the relevance of pDCs in therapy for asthma, lung infections and cancer. However, it is to note that pDCs can also participate in suppressive networks via the recruitment of T regulatory cells. Further studies are needed to understand pDCs activity in the lung, not only to elucidate pathological mechanisms, but also to lead towards new therapeutic approaches for lung inflammatory-based diseases. The article also outlines recent patents on plasmacytoid DCs.

  4. Clinical View on the Importance of Dendritic Cells in Asthma

    PubMed Central

    Gaurav, Rohit; Agrawal, Devendra K.

    2015-01-01

    Summary Allergic asthma is characterized by airway hyperresponsiveness and inflammation and may lead to airway remodeling in uncontrolled cases. Genetic predisposition to an atopic phenotype plays a major component in the pathophysiology of asthma. However, with tremendous role of epigenetic factors and environmental stimuli in precipitating an immune response, the underlying pathophysiological mechanisms are complicated. Dendritic cells are principal antigen presenting cells and initiators of the immune response in allergic asthma. Their phenotype, guided by multiple factors may dictate the immune reaction to an allergic or tolerogenic response. Involvement of the local cytokine milieu, microbiome and interplay between immune cells add dimension to the fate of immune response. In addition to allergen exposure, these factors modulate DC phenotype and function. In this article, integration of many factors and pathways associated with the recruitment and activation of DCs in the pathophysiology of allergic asthma is presented in a clinical and translational manner. PMID:24128155

  5. Dendritic Cells in the Gut: Interaction with Intestinal Helminths

    PubMed Central

    Mendlovic, Fela; Flisser, Ana

    2010-01-01

    The mucosal environment in mammals is highly tolerogenic; however, after exposure to pathogens or danger signals, it is able to shift towards an inflammatory response. Dendritic cells (DCs) orchestrate immune responses and are highly responsible, through the secretion of cytokines and expression of surface markers, for the outcome of such immune response. In particular, the DC subsets found in the intestine have specialized functions and interact with different immune as well as nonimmune cells. Intestinal helminths primarily induce Th2 responses where DCs have an important yet not completely understood role. In addition, this cross-talk results in the induction of regulatory T cells (T regs) as a result of the homeostatic mucosal environment. This review highlights the importance of studying the particular relation “helminth-DC-milieu” in view of the significance that each of these factors plays. Elucidating the mechanisms that trigger Th2 responses may provide the understanding of how we might modulate inflammatory processes. PMID:20224759

  6. A polymeric bacterial protein activates dendritic cells via TLR4.

    PubMed

    Berguer, Paula M; Mundiñano, Juliana; Piazzon, Isabel; Goldbaum, Fernando A

    2006-02-15

    The enzyme lumazine synthase from Brucella spp. (BLS) is a highly immunogenic protein that folds as a stable dimer of pentamers. It is possible to insert foreign peptides and proteins at the 10 N terminus of BLS without disrupting its general folding, and these chimeras are very efficient to elicit systemic and oral immunity without adjuvants. In this study, we show that BLS stimulates bone marrow dendritic cells from mice in vitro to up-regulate the levels of costimulatory molecules (CD40, CD80, and CD86) and major histocompatibility class II Ag. Furthermore, the mRNA levels of several chemokines are increased, and proinflammatory cytokine secretion is induced upon exposure to BLS. In vivo, BLS increases the number of dendritic cells and their expression of CD62L in the draining lymph node. All of the observed effects are dependent on TLR4, and clearly independent of LPS contamination. The described characteristics of BLS make this protein an excellent candidate for vaccine development.

  7. Active specific T-cell-based immunotherapy for cancer: nucleic acids, peptides, whole native proteins, recombinant viruses, with dendritic cell adjuvants or whole tumor cell-based vaccines. Principles and future prospects.

    PubMed

    Fernandez, N; Duffour, M T; Perricaudet, M; Lotze, M T; Tursz, T; Zitvogel, L

    1998-03-01

    Whereas tumor cells are poor immunogens, recombinant tumor cells or dendritic cells as well as engineered viruses have been demonstrated to elicit specific antitumor immune responses leading to tumor growth suppression and long-lasting immunity in mouse tumor models. Single cytotoxic T lymphocyte-defined epitope-based strategies have proved useful for immunization in tumor-bearing mice. This strategy is under investigation in human melanoma, along with adjuvants such as cytokines or dendritic cells. Flt3L is an in vivo dendritic-cell growth factor that offers new prospects in the field of active specific immunotherapy. These immunotherapeutic approaches are being tested in clinical trials, and may open up novel avenues for disease-free patients with poor prognostic factors.

  8. Dendritic cell type-specific HIV-1 activation in effector T cells: implications for latent HIV-1 reservoir establishment.

    PubMed

    van der Sluis, Renée M; van Capel, Toni M M; Speijer, Dave; Sanders, Rogier W; Berkhout, Ben; de Jong, Esther C; Jeeninga, Rienk E; van Montfort, Thijs

    2015-06-01

    Latent HIV type I (HIV-1) infections can frequently occur in short-lived proliferating effector T lymphocytes. These latently infected cells could revert into resting T lymphocytes and thereby contribute to the establishment of the long-lived viral reservoir. Monocyte-derived dendritic cells can revert latency in effector T cells in vitro. Here we investigated the latency activation properties of tissue-specific immune cells, including a large panel of dendritic cell subsets, to explore in which body compartments effector T cells are most likely to maintain latent HIV-1 provirus and thus potentially contribute to the long-lived reservoir. Our results demonstrate that blood or genital tract dendritic cells do not activate latent provirus in effector T cells, whereas gut or lymphoid dendritic cells induce virus production from latently infected effector T cells in our in-vitro model for latency. Toll-like receptor 3-induced interferon production by myeloid dendritic cells abolished the dendritic cells' ability to induce viral gene expression. In this study, we show that HIV-1 provirus residing in effector T cells is activated from latency by tissue-specific dendritic cell subsets and other immune cells with remarkably different efficiencies.Our new assay system points to an important, neglected aspect of HIV-1 research: the ability of other immune cells, especially dendritic cells, to differentially affect latency establishment as well as virus reactivation.

  9. Supravital uptake of methylene blue by dendritic cells within stratified squamous epithelia: a light and electron microscope study.

    PubMed

    Müller, T

    1996-03-01

    Electron microscopic data on methylene blue staining of dendritic cells in the epithelia of the soft palate and skin of the mouse after supravital dye injection are presented. The ultra-structural details were compared with corresponding light microscopic findings. Methylene blue stained tissue was fixed by immersion in a paraformaldehyde-glutaraldehyde solution containing phosphomolybdic acid. The ensuing dye precipitate was stabilized by ammonium heptamolybdate. The light microscopic investigation revealed that selective staining of dendritic cells depended on the presence of ambient oxygen. In addition, delicate morphological characteristics, like spinous structures of the dendrites, were visible. Some cells also showed terminal enlargements of the dendrites close to the surface of the epithelium. In general, visualization of morphological detail was superior to that obtained by conventional histological and immunohistochemical procedures. Nerve fibers were also stained within the epithelium as well as the subepithelial connective tissue. At the electron microscopic level, the dye was clearly identified as an electron dense precipitate that accumulated primarily within the cytoplasm near the plasma membrane. Furthermore, it was bound to the chromatin of the nuclei. No significant staining of mitochondria or other organelles was seen. Within the cytoplasm, the oxygen-dependent binding sites may be associated with heme proteins that attract both the dye in its reduced lipophilic leuco form and oxygen, followed by generation of oxygen radicals and a reoxidation of the leuco form to the cationic blue dye. Because of its selectivity for intraepithelial dendritic cells, the method described here supplements immunocytochemical procedures at both the light and electron microscopic levels.

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

    PubMed Central

    Long-Hua, Qiu; Qin, Xiao; Jian, Wang; Xiao-Yuan, Feng

    2011-01-01

    Follicular dendritic cell sarcoma is a rare malignant neoplasm and little is known about its radiological features. We present here four cases of follicular dendritic cell sarcomas and we provide the image characteristics of these tumors to help radiologists recognize this entity when making a diagnosis. PMID:21228948

  11. Imaging findings of follicular dendritic cell sarcoma: report of four cases.

    PubMed

    Long-Hua, Qiu; Qin, Xiao; Ya-Jia, Gu; Jian, Wang; Xiao-Yuan, Feng

    2011-01-01

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

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

    SciTech Connect

    Macoch, Mélinda; Morzadec, Claudie; Fardel, Olivier; Vernhet, Laurent

    2013-01-15

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

  13. Broncho Alveolar Dendritic Cells and Macrophages Are Highly Similar to Their Interstitial Counterparts

    PubMed Central

    Maisonnasse, Pauline; Bordet, Elise; Bouguyon, Edwige; Bertho, Nicolas

    2016-01-01

    In human medicine, bronchoalveolar lavage is the main non-traumatic procedure allowing an insight into the respiratory Dendritic Cells (DC) and Macrophages populations. However, it has never been demonstrated in a relevant model that alveolar DC subpopulations were comparable to their interstitial counterparts. In a precedent work we observed that respiratory pig DC and Macrophages were more similar to the human ones than to the mouse ones. In the present work, thanks to our animal model, we were able to collect the rare bronchoalveolar DC and compare them to their interstitial counterparts. We observed that DC presented very similar gene-expression patterns in the alveolar and interstitial compartments, validating the study of human bronchoalveolar DC as surrogate of their interstitium counterparts. PMID:27992536

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

    PubMed Central

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

    2010-01-01

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

  15. Democracy-independence trade-off in oscillating dendrites and its implications for grid cells.

    PubMed

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

    2010-05-13

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

  16. Plasmacytoid Dendritic Cells Die by the CD8 T Cell-Dependent Perforin Pathway during Acute Nonviral Inflammation.

    PubMed

    Mossu, Adrien; Daoui, Anna; Bonnefoy, Francis; Aubergeon, Lucie; Saas, Philippe; Perruche, Sylvain

    2016-09-01

    Regulation of the inflammatory response involves the control of dendritic cell survival. To our knowledge, nothing is known about the survival of plasmacytoid dendritic cells (pDC) in such situation. pDC are specialized in type I IFN (IFN-I) secretion to control viral infections, and IFN-I also negatively regulate pDC survival during the course of viral infections. In this study, we asked about pDC behavior in the setting of virus-free inflammation. We report that pDC survival was profoundly reduced during different nonviral inflammatory situations in the mouse, through a mechanism independent of IFN-I and TLR signaling. Indeed, we demonstrated that during inflammation, CD8(+) T cells induced pDC apoptosis through the perforin pathway. The data suggest, therefore, that pDC have to be turned down during ongoing acute inflammation to not initiate autoimmunity. Manipulating CD8(+) T cell response may therefore represent a new therapeutic opportunity for the treatment of pDC-associated autoimmune diseases, such as lupus or psoriasis. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. Reovirus activates human dendritic cells to promote innate antitumor immunity.

    PubMed

    Errington, Fiona; Steele, Lynette; Prestwich, Robin; Harrington, Kevin J; Pandha, Hardev S; Vidal, Laura; de Bono, Johann; Selby, Peter; Coffey, Matt; Vile, Richard; Melcher, Alan

    2008-05-01

    Oncolytic viruses can exert their antitumor activity via direct oncolysis or activation of antitumor immunity. Although reovirus is currently under clinical investigation for the treatment of localized or disseminated cancer, any potential immune contribution to its efficacy has not been addressed. This is the first study to investigate the ability of reovirus to activate human dendritic cells (DC), key regulators of both innate and adaptive immune responses. Reovirus induced DC maturation and stimulated the production of the proinflammatory cytokines IFN-alpha, TNF-alpha, IL-12p70, and IL-6. Activation of DC by reovirus was not dependent on viral replication, while cytokine production (but not phenotypic maturation) was inhibited by blockade of PKR and NF-kappaB signaling. Upon coculture with autologous NK cells, reovirus-activated DC up-regulated IFN-gamma production and increased NK cytolytic activity. Moreover, short-term coculture of reovirus-activated DC with autologous T cells also enhanced T cell cytokine secretion (IL-2 and IFN-gamma) and induced non-Ag restricted tumor cell killing. These data demonstrate for the first time that reovirus directly activates human DC and that reovirus-activated DC stimulate innate killing by not only NK cells, but also T cells, suggesting a novel potential role for T cells in oncolytic virus-induced local tumor cell death. Hence reovirus recognition by DC may trigger innate effector mechanisms to complement the virus's direct cytotoxicity, potentially enhancing the efficacy of reovirus as a therapeutic agent.

  18. The dendritic cell side of the immunological synapse.

    PubMed

    Verboogen, Danielle R J; Dingjan, Ilse; Revelo, Natalia H; Visser, Linda J; ter Beest, Martin; van den Bogaart, Geert

    2016-02-01

    Immune responses are initiated by the interactions between antigen-presenting cells (APCs), such as dendritic cells (DCs), with responder cells, such as T cells, via a tight cellular contact interface called the immunological synapse. The immunological synapse is a highly organized subcellular structure that provides a platform for the presentation of antigen in major histocompatibility class I and II complexes (MHC class I and II) on the surface of the APC to receptors on the surface of the responder cells. In T cells, these contacts lead to highly polarized membrane trafficking that results in the local release of lytic granules and in the delivery and recycling of T cell receptors at the immunological synapse. Localized trafficking also occurs at the APC side of the immunological synapse, especially in DCs where antigen loaded in MHC class I and II is presented and cytokines are released specifically at the synapse. Whereas the molecular mechanisms underlying polarized membrane trafficking at the T cell side of the immunological synapse are increasingly well understood, these are still very unclear at the APC side. In this review, we discuss the organization of the APC side of the immunological synapse. We focus on the directional trafficking and release of membrane vesicles carrying MHC molecules and cytokines at the immunological synapses of DCs. We hypothesize that the specific delivery of MHC and the release of cytokines at the immunological synapse mechanistically resemble that of lytic granule release from T cells.

  19. The diverging roles of dendritic cells in kidney allotransplantation.

    PubMed

    Podestà, Manuel Alfredo; Cucchiari, David; Ponticelli, Claudio

    2015-07-01

    Dendritic cells (DCs) are a family of antigen presenting cells that play a paramount role in bridging innate and adaptive immunity. In murine models several subtypes of DCs have been identified, including classical DCs, monocyte-derived DCs, and plasmacytoid DCs. Quiescent, immature DCs and some subtypes of plasmacytoid cells favor the expression of regulatory T cells, but in an inflammatory milieu DCs become mature and after intercepting the antigen migrate to lymphatic system where they present the antigen to naïve T cells. Transplant rejection largely depends on the phenotype and maturation of DCs. The ischemia-reperfusion injury causes the release of endogenous molecules that are recognized as danger signals by the pattern recognition receptor of the innate immunity with subsequent activation of inflammatory cells and mediators. In this environment DCs become mature and migrate to lymphonodes where they present the alloantigen to T cells and direct their differentiation towards Th1 and Th17 effector cells. On the other hand, manipulation of DCs may favor T cell differentiation towards tolerant Th2 and T regulators (Treg). Experimental studies in murine models showed the possibility of inducing an operational tolerance by injecting immature tolerogenic DCs. Recently, such a possibility has been also confirmed in primates. Although manipulation of DCs may represent an important step ahead in kidney transplantation, a number of technical and ethical issues should be solved before its clinical application.

  20. Modulation of Dendritic Cell Activation and Subsequent Th1 Cell Polarization by Lidocaine

    PubMed Central

    Chung, Yeonseok

    2015-01-01

    Dendritic cells play an essential role in bridging innate and adaptive immunity by recognizing cellular stress including pathogen- and damage-associated molecular patterns and by shaping the types of antigen-specific T cell immunity. Although lidocaine is widely used in clinical settings that trigger cellular stress, it remains unclear whether such treatment impacts the activation of innate immune cells and subsequent differentiation of T cells. Here we showed that lidocaine inhibited the production of IL–6, TNFα and IL–12 from dendritic cells in response to toll-like receptor ligands including lipopolysaccharide, poly(I:C) and R837 in a dose-dependent manner. Notably, the differentiation of Th1 cells was significantly suppressed by the addition of lidocaine while the same treatment had little effect on the differentiation of Th17, Th2 and regulatory T cells in vitro. Moreover, lidocaine suppressed the ovalbumin-specific Th1 cell responses in vivo induced by the adoptive transfer of ovalbumin-pulsed dendritic cells. These results demonstrate that lidocaine inhibits the activation of dendritic cells in response to toll-like receptor signals and subsequently suppresses the differentiation of Th1 cell responses. PMID:26445366

  1. Oral prion disease pathogenesis is impeded in the specific absence of CXCR5-expressing dendritic cells.

    PubMed

    Bradford, Barry M; Reizis, Boris; Mabbott, Neil A

    2017-03-08

    After oral exposure the early replication of certain prion strains upon stromal-derived follicular dendritic cells (FDC) in the Peyer's patches in the small intestine is essential for the efficient spread of disease to the brain. However, little is known of how prions are initially conveyed from the gut lumen to establish infection on FDC. Our previous data suggest that mononuclear phagocytes such as CD11c(+) conventional dendritic cells play an important role in the initial propagation of prions from the gut lumen into Peyer's patches. But whether these cells conveyed orally-acquired prions towards FDC within Peyer's patches was not known. The chemokine CXCL13 is expressed by FDC and follicular stromal cells and modulates the homing of CXCR5-expressing cells towards the FDC-containing B cell follicles. Here, novel compound transgenic mice were created in which CXCR5-deficiency was specifically restricted to CD11c(+) cells. These mice were used to determine whether CXCR5-expressing conventional dendritic cells propagate prions towards FDC after oral exposure. Our data show that in the specific absence of CXCR5-expressing conventional dendritic cells the early accumulation of prions upon FDC in Peyer's patches and the spleen was impaired, and disease susceptibility significantly reduced. These data suggest that CXCR5-expressing conventional dendritic cells play an important role in the efficient propagation of orally-administered prions towards FDC within Peyer's patches in order to establish host infection.IMPORTANCE Many natural prion diseases are acquired by oral consumption of contaminated food or pasture. Once the prions reach the brain they cause extensive neurodegeneration which ultimately leads to death. In order for the prions to efficiently spread from the gut to the brain, they first replicate upon follicular dendritic cells within intestinal Peyer's patches. How the prions are first delivered to follicular dendritic cells to establish infection was

  2. Epstein-Barr Virus–induced Molecule 1 Ligand Chemokine Is Expressed by Dendritic Cells in Lymphoid Tissues and Strongly Attracts Naive T Cells and Activated B Cells

    PubMed Central

    Ngo, Vu N.; Lucy Tang, H.; Cyster, Jason G.

    1998-01-01

    Movement of T and B lymphocytes through secondary lymphoid tissues is likely to involve multiple cues that help the cells navigate to appropriate compartments. Epstein-Barr virus– induced molecule 1 (EBI-1) ligand chemokine (ELC/MIP3β) is expressed constitutively within lymphoid tissues and may act as such a guidance cue. Here, we have isolated mouse ELC and characterized its expression pattern and chemotactic properties. ELC is expressed constitutively in dendritic cells within the T cell zone of secondary lymphoid tissues. Recombinant ELC was strongly chemotactic for naive (L-selectinhi) CD4 T cells and for CD8 T cells and weakly attractive for resting B cells and memory (L-selectinlo) CD4 T cells. After activation through the B cell receptor, the chemotactic response of B cells was enhanced. Like its human counterpart, murine ELC stimulated cells transfected with EBI-1/CC chemokine receptor 7 (CCR7). Our findings suggest a central role for ELC in promoting encounters between recirculating T cells and dendritic cells and in the migration of activated B cells into the T zone of secondary lymphoid tissues. PMID:9653094

  3. Epstein-Barr virus-induced molecule 1 ligand chemokine is expressed by dendritic cells in lymphoid tissues and strongly attracts naive T cells and activated B cells.

    PubMed

    Ngo, V N; Tang, H L; Cyster, J G

    1998-07-06

    Movement of T and B lymphocytes through secondary lymphoid tissues is likely to involve multiple cues that help the cells navigate to appropriate compartments. Epstein-Barr virus- induced molecule 1 (EBI-1) ligand chemokine (ELC/MIP3beta) is expressed constitutively within lymphoid tissues and may act as such a guidance cue. Here, we have isolated mouse ELC and characterized its expression pattern and chemotactic properties. ELC is expressed constitutively in dendritic cells within the T cell zone of secondary lymphoid tissues. Recombinant ELC was strongly chemotactic for naive (L-selectinhi) CD4 T cells and for CD8 T cells and weakly attractive for resting B cells and memory (L-selectinlo) CD4 T cells. After activation through the B cell receptor, the chemotactic response of B cells was enhanced. Like its human counterpart, murine ELC stimulated cells transfected with EBI-1/CC chemokine receptor 7 (CCR7). Our findings suggest a central role for ELC in promoting encounters between recirculating T cells and dendritic cells and in the migration of activated B cells into the T zone of secondary lymphoid tissues.

  4. 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.

  5. Blood-derived dermal langerin+ dendritic cells survey the skin in the steady state

    PubMed Central

    Ginhoux, Florent; Collin, Matthew P.; Bogunovic, Milena; Abel, Michal; Leboeuf, Marylene; Helft, Julie; Ochando, Jordi; Kissenpfennig, Adrien; Malissen, Bernard; Grisotto, Marcos; Snoeck, Hans; Randolph, Gwendalyn; Merad, Miriam

    2007-01-01

    Langerin is a C-type lectin receptor that recognizes glycosylated patterns on pathogens. Langerin is used to identify human and mouse epidermal Langerhans cells (LCs), as well as migratory LCs in the dermis and the skin draining lymph nodes (DLNs). Using a mouse model that allows conditional ablation of langerin+ cells in vivo, together with congenic bone marrow chimeras and parabiotic mice as tools to differentiate LC- and blood-derived dendritic cells (DCs), we have revisited the origin of langerin+ DCs in the skin DLNs. Our results show that in contrast to the current view, langerin+CD8− DCs in the skin DLNs do not derive exclusively from migratory LCs, but also include blood-borne langerin+ DCs that transit through the dermis before reaching the DLN. The recruitment of circulating langerin+ DCs to the skin is dependent on endothelial selectins and CCR2, whereas their recruitment to the skin DLNs requires CCR7 and is independent of CD62L. We also show that circulating langerin+ DCs patrol the dermis in the steady state and migrate to the skin DLNs charged with skin antigens. We propose that this is an important and previously unappreciated element of immunosurveillance that needs to be taken into account in the design of novel vaccine strategies. PMID:18086862

  6. Curcumin prevents human dendritic cell response to immune stimulants

    SciTech Connect

    Shirley, Shawna A.; Montpetit, Alison J.; Lockey, R.F.; Mohapatra, Shyam S.

    2008-09-26

    Curcumin, a compound found in the Indian spice turmeric, has anti-inflammatory and immunomodulatory properties, though the mechanism remains unclear. Dendritic cells (DCs) are important to generating an immune response and the effect of curcumin on human DCs has not been explored. The role curcumin in the DC response to bacterial and viral infection was investigated in vitro using LPS and Poly I:C as models of infection. CD14{sup +} monocytes, isolated from human peripheral blood, were cultured in GM-CSF- and IL-4-supplemented medium to generate immature DCs. Cultures were incubated with curcumin, stimulated with LPS or Poly I:C and functional assays were performed. Curcumin prevents DCs from responding to immunostimulants and inducing CD4{sup +} T cell proliferation by blocking maturation marker, cytokine and chemokine expression and reducing both migration and endocytosis. These data suggest a therapeutic role for curcumin as an immune suppressant.

  7. Dendritic cells and cytokines in immune re