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Sample records for dendritic cell tracking

  1. 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

  2. In Vivo Dendritic Cell Tracking Using Fluorescence Lifetime Imaging and Near-Infrared-Emissive Polymersomes

    PubMed Central

    Christian, Natalie A.; Benencia, Fabian; Milone, Michael C.; Li, Guizhi; Frail, Paul R.; Therien, Michael J.; Coukos, George; Hammer, Daniel A.

    2009-01-01

    Purpose: Noninvasive in vivo cell-tracking techniques are necessary to advance the field of cellular-based therapeutics as well as to elucidate mechanisms governing in vivo cell biology. Fluorescence is commonly used for in vitro and postmortem biomedical studies but has been limited by autofluorescence at the whole-animal level. Procedures: In this report, we demonstrate the ability of in vivo fluorescent lifetime imaging to remove autofluorescence and thereby enable in vivo dendritic cell tracking in naïve mice. Specifically, we track mature dendritic cells (DCs) labeled internally with near-infrared-emissive polymersomes (NIR-DCs). Results: We establish the ability to detect labeled cells in vivo and image NIR-DC trafficking after both intravenous and subcutaneous delivery. In addition, we demonstrate the longitudinal capacity of this method by characterizing NIR-DC migration kinetics in the popliteal lymph node. Conclusions: This work provides a tool to evaluate dendritic-cell-based immunotherapy and generates novel opportunities for in vivo fluorescence imaging. PMID:19194761

  3. Clinical grade OK432-activated dendritic cells: in vitro characterization and tracking during intralymphatic delivery.

    PubMed

    West, Emma; Morgan, Ruth; Scott, Karen; Merrick, Alison; Lubenko, Anatole; Pawson, David; Selby, Peter; Hatfield, Paul; Prestwich, Robin; Fraser, Sheila; Eves, David; Anthoney, Alan; Twelves, Chris; Beirne, Debbie; Patel, Poulam; O'Donnell, Dearbhaile; Watt, Suzanne; Waller, Michael; Dietz, Allan; Robinson, Philip; Melcher, Alan

    2009-01-01

    Dendritic cells (DC) are under intense preclinical and early clinical evaluation for the immunotherapy of cancer. However, the optimal culture conditions and route of delivery for DC vaccination have not been established. Here we describe the first human application of DC matured with the bacterial agent OK432 (OK-DC), using a short-term serum-free culture protocol, which generates mature DC from CD14+ precursors after 5 days. These cells were prepared within the framework of a National Blood Service facility, demonstrating that DC represent a product which is potentially deliverable alongside current standardized cell therapies within the UK National Health Service. In vitro analysis confirmed that OK-DC were mature, secreted tumor necrosis factor-alpha, interleukin-6, and interleukin-12, and stimulated both T cell and natural killer cell function. To explore effective delivery of OK-DC to lymph nodes, we performed an initial clinical tracking study of radioactively labeled, unpulsed OK-DC after intralymphatic injection into the dorsum of the foot. We showed that injected DC rapidly localized to ipsilateral pelvic lymph nodes, but did not disseminate to more distant nodes over a 48-hour period. There was no significant toxicity associated with OK-DC delivery. These results show that OK-DC are suitable for clinical use, and that intralymphatic delivery is feasible for localizing cells to sites where optimal priming of innate and adaptive antitumor immunity is likely to occur.

  4. In vivo Tracking of Dendritic Cell using MRI Reporter Gene, Ferritin

    PubMed Central

    Kim, Hoe Suk; Woo, Jisu; Lee, Jae Hoon; Joo, Hyun Jung; Choi, YoonSeok; Kim, Hyeonjin; Moon, Woo Kyung; Kim, Seung Ja

    2015-01-01

    The noninvasive imaging of dendritic cells (DCs) migrated into lymph nodes (LNs) can provide helpful information on designing DCs-based immunotherapeutic strategies. This study is to investigate the influence of transduction of human ferritin heavy chain (FTH) and green fluorescence protein (GFP) genes on inherent properties of DCs, and the feasibility of FTH as a magnetic resonance imaging (MRI) reporter gene to track DCs migration into LNs. FTH-DCs were established by the introduction of FTH and GFP genes into the DC cell line (DC2.4) using lentivirus. The changes in the rate of MRI signal decay (R2*) resulting from FTH transduction were analyzed in cell phantoms as well as popliteal LN of mice after subcutaneous injection of those cells into hind limb foot pad by using a multiple gradient echo sequence on a 9.4 T MR scanner. The transduction of FTH and GFP did not influence the proliferation and migration abilities of DCs. The expression of co-stimulatory molecules (CD40, CD80 and CD86) in FTH-DCs was similar to that of DCs. FTH-DCs exhibited increased iron storage capacity, and displayed a significantly higher transverse relaxation rate (R2*) as compared to DCs in phantom. LNs with FTH-DCs exhibited negative contrast, leading to a high R2* in both in vivo and ex vivo T2*-weighted images compared to DCs. On histological analysis FTH-DCs migrated to the subcapsular sinus and the T cell zone of LN, where they highly expressed CD25 to bind and stimulate T cells. Our study addresses the feasibility of FTH as an MRI reporter gene to track DCs migration into LNs without alteration of their inherent properties. This study suggests that FTH-based MRI could be a useful technique to longitudinally monitor DCs and evaluate the therapeutic efficacy of DC-based vaccines. PMID:25993535

  5. Tracking the Migration of Dendritic Cells By In Vivo Optical Imaging1

    PubMed Central

    Pham, Wellington; Xie, Jingping; Gore, John C

    2007-01-01

    We report herein a method to track the migration of dendritic cells (DCs) using optical imaging. With the assistance of the delivery module, fluorescein isothiocyanate (FITC) could internalize inside DCs within 15 minutes of incubation. The fluorescent signal was mostly cytoplasmic and could be detected using in vivo imaging. Furthermore, we observed that the probe did not interfere with the DCs maturation as we assessed the expression of several surface markers. The labeled DCs secreted interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-α) and stimulated the proliferation of CD4+ T lymphocytes responding to lipopolysaccharide (LPS) stimulation. We have systematically compared the probe uptake between mature and immature DCs. The study showed that the latter phagocytosed the probe slightly better than the former. Intravital imaging of treated mice showed the migration of DCs to lymph nodes (LNs), which is confirmed by immunohistochemistry. Taken together, we demonstrated the potential use of optical imaging for tracking the migration of DCs and homing in vivo. The delivery molecules could also be used on other imaging modalities or for delivery of antigens. PMID:18084620

  6. In vivo tracking and immunological properties of pulsed porcine monocyte-derived dendritic cells.

    PubMed

    Crisci, Elisa; Fraile, Lorenzo; Novellas, Rosa; Espada, Yvonne; Cabezón, Raquel; Martínez, Jorge; Cordoba, Lorena; Bárcena, Juan; Benitez-Ribas, Daniel; Montoya, María

    2015-02-01

    Cellular therapies using immune cells and in particular dendritic cells (DCs) are being increasingly applied in clinical trials and vaccines. Their success partially depends on accurate delivery of cells to target organs or migration to lymph nodes. Delivery and subsequent migration of cells to regional lymph nodes is essential for effective stimulation of the immune system. Thus, the design of an optimal DC therapy would be improved by optimizing technologies for monitoring DC trafficking. Magnetic resonance imaging (MRI) represents a powerful tool for non-invasive imaging of DC migration in vivo. Domestic pigs share similarities with humans and represent an excellent animal model for immunological studies. The aim of this study was to investigate the possibility using pigs as models for DC tracking in vivo. Porcine monocyte derived DC (MoDC) culture with superparamagnetic iron oxide (SPIO) particles was standardized on the basis of SPIO concentration and culture viability. Phenotype, cytokine production and mixed lymphocyte reaction assay confirmed that porcine SPIO-MoDC culture were similar to mock MoDCs and fully functional in vivo. Alike, similar patterns were obtained in human MoDCs. After subcutaneous inoculation in pigs, porcine SPIO-MoDC migration to regional lymph nodes was detected by MRI and confirmed by Perls staining of draining lymph nodes. Moreover, after one dose of virus-like particles-pulsed MoDCs specific local and systemic responses were confirmed using ELISPOT IFN-γ in pigs. In summary, the results in this work showed that after one single subcutaneous dose of pulsed MoDCs, pigs were able to elicit specific local and systemic immune responses. Additionally, the dynamic imaging of MRI-based DC tracking was shown using SPIO particles. This proof-of-principle study shows the potential of using pigs as a suitable animal model to test DC trafficking with the aim of improving cellular therapies.

  7. Tracking of dendritic cell migration into lymph nodes using molecular imaging with sodium iodide symporter and enhanced firefly luciferase genes.

    PubMed

    Lee, Ho Won; Yoon, Seung Yun; Singh, Thoudam Debraj; Choi, Yoon Ju; Lee, Hong Je; Park, Ji Young; Jeong, Shin Young; Lee, Sang-Woo; Ha, Jeoung-Hee; Ahn, Byeong-Cheol; Jeon, Yong Hyun; Lee, Jaetae

    2015-05-14

    We sought to evaluate the feasibility of molecular imaging using the human sodium iodide symporter (hNIS) gene as a reporter, in addition to the enhanced firefly luciferase (effluc) gene, for tracking dendritic cell (DCs) migration in living mice. A murine dendritic cell line (DC2.4) co-expressing hNIS and effluc genes (DC/NF) was established. For the DC-tracking study, mice received either parental DCs or DC/NF cells in the left or right footpad, respectively, and combined I-124 PET/CT and bioluminescence imaging (BLI) were performed. In vivo PET/CT imaging with I-124 revealed higher activity of the radiotracer in the draining popliteal lymph nodes (DPLN) of the DC/NF injection site at day 1 than DC injection site (p < 0.05). The uptake value further increased at day 4 (p < 0.005). BLI also demonstrated migration of DC/NF cells to the DPLNs at day 1 post-injection, and signals at the DPLNs were much higher at day 4. These data support the feasibility of hNIS reporter gene imaging in the tracking of DC migration to lymphoid organs in living mice. DCs expressing the NIS reporter gene could be a useful tool to optimize various strategies of cell-based immunotherapy.

  8. Superparamagnetic MRI probes for in vivo tracking of dendritic cell migration with a clinical 3 T scanner.

    PubMed

    Xu, Ye; Wu, Changqiang; Zhu, Wencheng; Xia, Chunchao; Wang, Dan; Zhang, Houbin; Wu, Jun; Lin, Gan; Wu, Bing; Gong, Qiyong; Song, Bin; Ai, Hua

    2015-07-01

    Dendritic cell (DC) based vaccines have shown promising results in the immunotherapy of cancers and other diseases. How to track the in vivo fate of DC vaccines will provide important insights to the final therapeutic results. In this study, we chose magnetic resonance imaging (MRI) to track murine DCs migration to the draining lymph node under a clinical 3 T scanner. Different from labeling immature DCs usually reported in literature, this study instead labeled matured DC with superparamagnetic iron oxide (SPIO) nanoparticle based imaging probes. The labeling process did not show negative impacts on cell viability, morphology, and surface biomarker expression. To overcome the imaging challenges brought by the limitations of the scanner, the size of lymph node, and the number of labeled cell, we optimized MRI pulse sequences. As a result, the signal reduction, caused either by gelatin phantoms containing as low as 12 SPIO-laden cells in each voxel or by the homing SPIO-laden DCs within the draining nodes after footpad injection of only 1 × 10(5) cells, can be clearly depicted under a 3 T MR scanner. Overall, the MRI labeling probes offer a low-toxic and high-efficient MR imaging platform for the assessment of DC-based immunotherapies.

  9. Dendritic morphogenesis of cerebellar Purkinje cells through extension and retraction revealed by long-term tracking of living cells in vitro.

    PubMed

    Tanaka, M; Yanagawa, Y; Obata, K; Marunouchi, T

    2006-08-25

    Cerebellar Purkinje cells have the most elaborate dendritic trees among the neurons in the CNS. To investigate the dynamic aspects of dendritic morphogenesis of Purkinje cells, we performed a long-term analysis of living cells in cerebellar cell cultures derived from glutamate decarboxylase 67-green fluorescent protein mice. Most Purkinje cells had several primary dendrites during the 25-day culture period. Repeated observation of green fluorescent protein-expressing Purkinje cells over a period of 10-25 days in vitro demonstrated that not only extension, but also retraction of primary dendrites occurred during this culture period. Interestingly, both extension and retraction of primary dendrites were active between 10 and 15 days in vitro, and retraction of a primary dendrite occurred concomitantly with elongation of other primary dendrites in the same cell. Analysis of the morphological characteristics of the retracted primary dendrites demonstrated that shorter and less branched primary dendrites tended to retract. Furthermore, treatment with an inhibitor of calcium/calmodulin-dependent protein kinase II reduced the number of primary dendrites specifically during 5-15 days in vitro, the culture period when the extension and retraction of primary dendrites occurred actively. Blockade of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate-type glutamate receptors also reduced the number of primary dendrites during the same culture period, while inhibition of glutamate transporters increased the number. These findings suggest that the final morphology of Purkinje cells is achieved not only through extension, but also through retraction of their dendrites, and that calcium/calmodulin-dependent protein kinase II and neuronal activity are involved in this dendritic morphogenesis.

  10. Finite-particle tracking reveals submicroscopic-size changes of mitochondria during transport in mitral cell dendrites

    NASA Astrophysics Data System (ADS)

    Gennerich, Arne; Schild, Detlev

    2006-03-01

    The mechanisms of molecular motor regulation during bidirectional organelle transport are still uncertain. There is, for instance, the unsettled question of whether opposing motor proteins can be engaged in a tug-of-war. Clearly, any non-synchronous activation of the molecular motors of one cargo can principally lead to changes in the cargo's shape and size; the cargo's size and shape parameters would certainly be observables of such changes. We therefore set out to measure position, shape and size parameters of fluorescent mitochondria (during their transport) in dendrites of cultured neurons using a finite-particle tracking algorithm. Our data clearly show transport-related submicroscopic-size changes of mitochondria. The observed displacements of the mitochondrial front and rear ends are consistent with a model in which microtubule plus- and minus-end-directed motor proteins or motors of the same type but moving along anti-parallel microtubules are often out-of-phase and occasionally engaged in a tug-of-war. Mostly the leading and trailing ends of mitochondria undergo similar characteristic movements but with a substantial time delay between the displacements of both ends, a feature reminiscent of an inchworm-like motility mechanism. More generally, we demonstrate that observing the position, shape and size of actively transported finite objects such as mitochondria can yield information on organelle transport that is generally not accessible by tracking the organelles' centroid alone.

  11. 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.

  12. 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.

  13. 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

  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. 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.

  16. 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.

  17. 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

  18. [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.

  19. 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.

  20. 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

  1. 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.

  2. [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.

  3. 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

  4. 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.

  5. 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.

  6. ISOLATION OF CHICKEN FOLLICULAR DENDRITIC CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Plasmacytoid dendritic cells and autoimmune inflammation.

    PubMed

    Galicia, Georgina; Gommerman, Jennifer L

    2014-03-01

    Plasmacytoid dendritic cells (pDC) are a sub-population of dendritic cells (DC) that produce large amounts of type I interferon (IFN) in response to nucleic acids that bind and activate toll-like-receptor (TLR)9 and TLR7. Type I IFN can regulate the function of B, T, DC, and natural killer (NK) cells and can also alter the residence time of leukocytes within lymph nodes. Activated pDC can also function as antigen presenting cells (APC) and have the potential to prime and differentiate T cells into regulatory or inflammatory effector cells, depending on the context. In this review we discuss pDC ontogeny, function, trafficking, and activation. We will also examine how pDC can potentially be involved in regulating immune responses in the periphery as well as within the central nervous system (CNS) during multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE).

  12. Dendritic Cells, New Tools for Vaccination

    DTIC Science & Technology

    2003-01-01

    19], Borrelia burgdorferi [20] Chlamydia trachomatis [21] and Candida albicans [22]. C. albicans provides a paradigmatic example of how this ap... Borrelia burgdorferi -pulsed dendritic cells induce a protective immune response against tick-transmitted spirochetes, Infect. Immun. 65 (1997) 3386–3390

  13. Characterization of chicken dendritic cell markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. 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

  15. 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.

  16. Numerical study of dendritic growth during solidification using front-tracking method

    NASA Astrophysics Data System (ADS)

    Jaafar, Mohamad Ali; Gibout, Stéphane; Rousse, Daniel; Bédécarrats, Jean-Pierre

    2016-09-01

    A two dimensional front-tracking method is developed in order to model dendritic growth during solidification processes of pure substances. The method uses a sequential set of moving marker points to describe and track the liquid-solid interface which evolves over a fixed background mesh describing the whole medium. The code behaviour is first checked by a simple stable case of solidification to provide homogeneous velocity at the interface. Then, test examples of unstable solidification cases considering different modes of anisotropy are performed. Finally, interface evolution, with primary and secondary branches, is described, showing the ability of the code to study realistic dendritic growth characteristics.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. [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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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).

  11. Divergent Effects of Dendritic Cells on Pancreatitis

    DTIC Science & Technology

    2015-09-01

    responses. Our work utilizes murine models and human tissues. Dendritic cells in mice express MHC II and the integrin CD11c. They are proficient in...CD54), and co-stimulatory molecules (CD80, CD86) in the pancreas and spleen in control mice and in models of pancreatitis. We showed that DC... generated BMDC in vitro from BM progenitors using GMCSF (20 ng/ml) in 8 day cultures. Mice were adoptively transferred with 1x106 BMDC after daily caerulein

  12. 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.

  13. Sensitivity analysis of dendritic growth kinetics in a Bridgman furnace front tracking model

    NASA Astrophysics Data System (ADS)

    Mooney, R. P.; McFadden, S.

    2016-03-01

    A directional solidification experiment of a Ti-Al-Nb-B-C alloy by power down method is simulated using a Bridgman furnace front tracking model. The effect of varying the dendritic growth parameters; C, the columnar dendrite growth coefficient, and n, the undercooling exponent, is investigated. A matrix of growth coefficients and undercooling exponents - at three levels each, based around a growth law for Ti-46wt.%Al - is applied in simulations, and the effect on columnar dendrite tip temperature, tip velocity, and tip temperature gradient is observed. The simulation results show that the dendrite tip velocity and temperature gradient at the tip are practically unaffected by the use of different growth parameters. However, the predicted columnar dendrite tip undercooling did vary to give the required dendrite tip velocity. This finding has implications for the analysis of microstructural transitions, such as the Columnar to Equiaxed Transition (CET). In conclusion, it is suggested that, for transient solidification conditions, a CET prediction criterion based on tip undercooling is preferable to one that uses growth velocity.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. Aptamer technology for tracking cells' status & function.

    PubMed

    Wiraja, Christian; Yeo, David; Lio, Daniel; Labanieh, Louai; Lu, Mengrou; Zhao, Weian; Xu, Chenjie

    2014-01-01

    In fields such as cancer biology and regenerative medicine, obtaining information regarding cell bio-distribution, tropism, status, and other cellular functions are highly desired. Understanding cancer behaviors including metastasis is important for developing effective cancer treatments, while assessing the fate of therapeutic cells following implantation is critical to validate the efficacy and efficiency of the therapy. For visualization purposes with medical imaging modalities (e.g. magnetic resonance imaging), cells can be labeled with contrast agents (e.g. iron-oxide nanoparticles), which allows their identification from the surrounding environment. Despite the success of revealing cell biodistribution in vivo, most of the existing agents do not provide information about the status and functions of cells following transplantation. The emergence of aptamers, single-stranded RNA or DNA oligonucleotides of 15 to 60 bases in length, is a promising solution to address this need. When aptamers bind specifically to their cognate molecules, they undergo conformational changes which can be transduced into a change of imaging contrast (e.g. optical, magnetic resonance). Thus by monitoring this signal change, researchers can obtain information about the expression of the target molecules (e.g. mRNA, surface markers, cell metabolites), which offer clues regarding cell status/function in a non-invasive manner. In this review, we summarize recent efforts to utilize aptamers as biosensors for monitoring the status and function of transplanted cells. We focus on cancer cell tracking for cancer study, stem cell tracking for regenerative medicine, and immune cell (e.g. dendritic cells) tracking for immune therapy.

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

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

    PubMed

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

    2016-01-01

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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Dynamic imaging of cell-free and cell-associated viral capture in mature dendritic cells.

    PubMed

    Izquierdo-Useros, Nuria; Esteban, Olga; Rodriguez-Plata, Maria T; Erkizia, Itziar; Prado, Julia G; Blanco, Julià; García-Parajo, Maria F; Martinez-Picado, Javier

    2011-12-01

    Dendritic cells (DCs) capture human immunodeficiency virus (HIV) through a non-fusogenic mechanism that enables viral transmission to CD4(+) T cells, contributing to in vivo viral dissemination. Although previous studies have provided important clues to cell-free viral capture by mature DCs (mDCs), dynamic and kinetic insight on this process is still missing. Here, we used three-dimensional video microscopy and single-particle tracking approaches to dynamically dissect both cell-free and cell-associated viral capture by living mDCs. We show that cell-free virus capture by mDCs operates through three sequential phases: virus binding through specific determinants expressed in the viral particle, polarized or directional movements toward concrete regions of the cell membrane and virus accumulation in a sac-like structure where trapped viral particles display a hindered diffusive behavior. Moreover, real-time imaging of cell-associated viral transfer to mDCs showed a similar dynamics to that exhibited by cell-free virus endocytosis leading to viral accumulation in compartments. However, cell-associated HIV type 1 transfer to mDCs was the most effective pathway, boosted throughout enhanced cellular contacts with infected CD4(+) T cells. Our results suggest that in lymphoid tissues, mDC viral uptake could occur either by encountering cell-free or cell-associated virus produced by infected cells generating the perfect scenario to promote HIV pathogenesis and impact disease progression.

  19. 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

  20. [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.

  1. Three-dimensional tracking and analysis of ion channel signals across dendritic arbors

    PubMed Central

    Ginger, Melanie; Broser, Philip; Frick, Andreas

    2013-01-01

    Most neuron types possess elaborate dendritic arbors that receive and integrate excitatory and inhibitory inputs from numerous other neurons to give rise to cell-type specific firing patterns. The computational properties of these dendrites are therefore crucial for neuronal information processing, and are strongly determined by the expression of many types of voltage-gated ion channels in their membrane. The dendritic distribution patterns of these ion channels are characteristic for each ion channel type, are dependent on the neuronal identity, and can be modified in a plastic or pathophysiological manner. We present a method that enables us to semi-automatically map and quantify in 3D the expression levels of specific ion channel types across the entire dendritic arbor. To achieve this, standard immunohistochemistry was combined with reconstruction and quantification procedures for the localization and relative distribution of ion channels with respect to dendritic morphology. This method can, in principle, be applied to any fluorescent signal, including fluorescently tagged membrane proteins, RNAs, or intracellular signaling molecules. PMID:23576958

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Vaccination with Dendritic Cell Myeloma Fusions in Conjuction with Stem Cell Transplantation and PD-1 Blockade

    DTIC Science & Technology

    2015-07-01

    Award Number: W81XWH-09-1-0296 TITLE: Vaccination with Dendritic Cell Myeloma Fusions in Conjuction with Stem Cell Transplantation and PD-1...Addendum 3. DATES COVERED (From - To) 1May2014 - 30Apr2015 4. TITLE AND SUBTITLE Vaccination with Dendritic Cell Myeloma Fusions in Conjuction with Stem...anti-PD1 antibody (CT-011) alone (Cohort 1) and in conjunction with a dendritic cell/myeloma fusion cell vaccine (Cohort 2) following autologous

  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. 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

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. Migratory dermal dendritic cells act as rapid sensors of protozoan parasites.

    PubMed

    Ng, Lai Guan; Hsu, Alice; Mandell, Michael A; Roediger, Ben; Hoeller, Christoph; Mrass, Paulus; Iparraguirre, Amaya; Cavanagh, Lois L; Triccas, James A; Beverley, Stephen M; Scott, Phillip; Weninger, Wolfgang

    2008-11-01

    Dendritic cells (DC), including those of the skin, act as sentinels for intruding microorganisms. In the epidermis, DC (termed Langerhans cells, LC) are sessile and screen their microenvironment through occasional movements of their dendrites. The spatio-temporal orchestration of antigen encounter by dermal DC (DDC) is not known. Since these cells are thought to be instrumental in the initiation of immune responses during infection, we investigated their behavior directly within their natural microenvironment using intravital two-photon microscopy. Surprisingly, we found that, under homeostatic conditions, DDC were highly motile, continuously crawling through the interstitial space in a Galpha(i) protein-coupled receptor-dependent manner. However, within minutes after intradermal delivery of the protozoan parasite Leishmania major, DDC became immobile and incorporated multiple parasites into cytosolic vacuoles. Parasite uptake occurred through the extension of long, highly dynamic pseudopods capable of tracking and engulfing parasites. This was then followed by rapid dendrite retraction towards the cell body. DDC were proficient at discriminating between parasites and inert particles, and parasite uptake was independent of the presence of neutrophils. Together, our study has visualized the dynamics and microenvironmental context of parasite encounter by an innate immune cell subset during the initiation of the immune response. Our results uncover a unique migratory tissue surveillance program of DDC that ensures the rapid detection of pathogens.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  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. 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.

  9. Langerhans cells and lymph node dendritic cells express the tight junction component claudin-1.

    PubMed

    Zimmerli, Simone C; Hauser, Conrad

    2007-10-01

    Claudin-1 is a critical structural component of tight junctions that have an important role in adhesive properties, barrier function, and paracellular transport of epithelia and other nonhematopoietic tissues. We found claudin-1 in murine CD207+ Langerhans cells (LC) residing in epidermis. Claudin-1 was not detected in other skin dendritic cells (DC). LC expressed claudin-1 in steady state and inflamed skin. Claudin-1 was demonstrated further in lymph node LC under steady state and inflammatory conditions, including after direct tracking with tetramethylrhodamine-isothiocyanate (TRITC). All subsets of skin draining lymph node DC defined by CD205, CD11b, CD11c, and CD8, including a presumably blood-borne lymph node resident CD8+CD207+ LC population, were claudin-1+. TRITC tracking demonstrated claudin-1 in CD207- skin migrant DC in the lymph node, suggesting upregulation of this molecule during migration or once arrived in the lymph node. Claudin-1 expression in CD207+ cells was confirmed at the protein and mRNA levels. Transforming growth factor-beta, a factor critical for the induction of LC in vitro and in vivo, stimulated the accumulation of claudin-1 mRNA and protein when added to bone marrow cells cultured with GM-CSF and IL-4. Claudin-1 may thus have an important function in adhesion and/or migration of LC.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 19F MRI for quantitative in vivo cell tracking

    PubMed Central

    Srinivas, Mangala; Heerschap, Arend; Ahrens, Eric T.; Figdor, Carl G.; de Vries, I. Jolanda M.

    2010-01-01

    Cellular therapy, including stem cell transplants and dendritic cell vaccines, is typically monitored for dosage optimization, accurate delivery and localization using non-invasive imaging, of which magnetic resonance imaging (MRI) is a key modality. 19F MRI retains the advantages of MRI as an imaging modality, while allowing direct detection of labelled cells for unambiguous identification and quantification, unlike typical metal-based contrast agents. Recent developments in 19F MRI-based in vivo cell quantification, the existing clinical use of 19F compounds and current explosive interest in cellular therapeutics have brought 19F imaging technology closer to clinical application. We review the application of 19F MRI to cell tracking, discussing intracellular 19F labels, cell labelling and in vivo quantification, as well as the potential clinical use of 19F MRI. PMID:20427096

  16. 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

  17. A Probabilistic Cell Tracking Algorithm

    NASA Astrophysics Data System (ADS)

    Steinacker, Reinhold; Mayer, Dieter; Leiding, Tina; Lexer, Annemarie; Umdasch, Sarah

    2013-04-01

    The research described below was carried out during the EU-Project Lolight - development of a low cost, novel and accurate lightning mapping and thunderstorm (supercell) tracking system. The Project aims to develop a small-scale tracking method to determine and nowcast characteristic trajectories and velocities of convective cells and cell complexes. The results of the algorithm will provide a higher accuracy than current locating systems distributed on a coarse scale. Input data for the developed algorithm are two temporally separated lightning density fields. Additionally a Monte Carlo method minimizing a cost function is utilizied which leads to a probabilistic forecast for the movement of thunderstorm cells. In the first step the correlation coefficients between the first and the second density field are computed. Hence, the first field is shifted by all shifting vectors which are physically allowed. The maximum length of each vector is determined by the maximum possible speed of thunderstorm cells and the difference in time for both density fields. To eliminate ambiguities in determination of directions and velocities, the so called Random Walker of the Monte Carlo process is used. Using this method a grid point is selected at random. Moreover, one vector out of all predefined shifting vectors is suggested - also at random but with a probability that is related to the correlation coefficient. If this exchange of shifting vectors reduces the cost function, the new direction and velocity are accepted. Otherwise it is discarded. This process is repeated until the change of cost functions falls below a defined threshold. The Monte Carlo run gives information about the percentage of accepted shifting vectors for all grid points. In the course of the forecast, amplifications of cell density are permitted. For this purpose, intensity changes between the investigated areas of both density fields are taken into account. Knowing the direction and speed of thunderstorm

  18. 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.

  19. Tracking stem cells in the cardiovascular system.

    PubMed

    Chemaly, Elie R; Yoneyama, Ryuichi; Frangioni, John V; Hajjar, Roger J

    2005-11-01

    Stem cells are a promising approach to cardiovascular therapeutics. Animal experiments have assessed the fate of injected stem cells through ex vivo methods on sacrificed animals. Approaches are needed for in vivo tracking of stem cells. Various imaging techniques and contrast agents for stem cell tracking will be reviewed.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  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. Chemotactic Migration of T Cells towards Dendritic Cells Promotes the Detection of Rare Antigens

    PubMed Central

    Vroomans, Renske M. A.; Marée, Athanasius F. M.; de Boer, Rob J.; Beltman, Joost B.

    2012-01-01

    In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs) has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs) carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data. PMID:23166480

  12. Chemotactic migration of T cells towards dendritic cells promotes the detection of rare antigens.

    PubMed

    Vroomans, Renske M A; Marée, Athanasius F M; de Boer, Rob J; Beltman, Joost B

    2012-01-01

    In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs) has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs) carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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

  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. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. [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.

  3. 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.

  4. 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

  5. Resolution of de novo HIV production and trafficking in immature dendritic cells.

    PubMed

    Turville, Stuart G; Aravantinou, Meropi; Stössel, Hella; Romani, Nikolaus; Robbiani, Melissa

    2008-01-01

    The challenge in observing de novo virus production in human immunodeficiency virus (HIV)-infected dendritic cells (DCs) is the lack of resolution between cytosolic immature and endocytic mature HIV gag protein. To track HIV production, we developed an infectious HIV construct bearing a diothiol-resistant tetracysteine motif (dTCM) at the C terminus of HIV p17 matrix within the HIV gag protein. Using this construct in combination with biarsenical dyes, we observed restricted staining of the dTCM to de novo-synthesized uncleaved gag in the DC cytosol. Co-staining with HIV gag antibodies, reactive to either p17 matrix or p24 capsid, preferentially stained mature virions and thus allowed us to track the virus at distinct stages of its life cycle within DCs and upon transfer to neighboring DCs or T cells. Thus, in staining HIV gag with biarsenical dye system in situ, we characterized a replication-competent virus capable of being tracked preferentially within infected leukocytes and observed in detail the dynamic nature of the HIV production and transfer in primary DCs.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Airway epithelial IL-15 transforms monocytes into dendritic cells.

    PubMed

    Regamey, Nicolas; Obregon, Carolina; Ferrari-Lacraz, Sylvie; van Leer, Coretta; Chanson, Marc; Nicod, Laurent P; Geiser, Thomas

    2007-07-01

    IL-15 has recently been shown to induce the differentiation of functional dendritic cells (DCs) from human peripheral blood monocytes. Since DCs lay in close proximity to epithelial cells in the airway mucosa, we investigated whether airway epithelial cells release IL-15 in response to inflammatory stimuli and thereby induce differentiation and maturation of DCs. Alveolar (A549) and bronchial (BEAS-2B) epithelial cells produced IL-15 spontaneously and in a time- and dose-dependent manner after stimulation with IL-1beta, IFN-gamma, or TNF-alpha. Airway epithelial cell supernatants induced an increase of IL-15Ralpha gene expression in ex vivo monocytes, and stimulated DCs enhanced their IL-15Ralpha gene expression up to 300-fold. Airway epithelial cell-conditioned media induced the differentiation of ex vivo monocytes into partially mature DCs (HLA-DR+, DC-SIGN+, CD14+, CD80-, CD83+, CD86+, CCR3+, CCR6(+), CCR7-). Based on their phenotypic (CD123+, BDCA2+, BDCA4+, BDCA1(-), CD1a-) and functional properties (limited maturation upon stimulation with LPS and limited capacity to induce T cell proliferation), these DCs resembled plasmacytoid DCs. The effects of airway epithelial cell supernatants were largely blocked by a neutralizing monoclonal antibody to IL-15. Thus, our results demonstrate that airway epithelial cell-conditioned media have the capacity to differentiate monocytes into functional DCs, a process substantially mediated by epithelial-derived IL-15.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus

    NASA Astrophysics Data System (ADS)

    Hole, Camaron R.; Bui, Hoang; Wormley, Floyd L.; Wozniak, Karen L.

    2012-10-01

    Cryptococcus neoformans is an opportunistic pulmonary fungal pathogen that disseminates to the CNS causing fatal meningitis in immunocompromised patients. Dendritic cells (DCs) phagocytose C. neoformans following inhalation. Following uptake, cryptococci translocate to the DC lysosomal compartment and are killed by oxidative and non-oxidative mechanisms. DC lysosomal extracts kill cryptococci in vitro; however, the means of antifungal activity remain unknown. Our studies determined non-oxidative antifungal activity by DC lysosomal extract. We examined DC lysosomal killing of cryptococcal strains, anti-fungal activity of purified lysosomal enzymes, and mechanisms of killing against C. neoformans. Results confirmed DC lysosome fungicidal activity against all cryptococcal serotypes. Purified lysosomal enzymes, specifically cathepsin B, inhibited cryptococcal growth. Interestingly, cathepsin B combined with its enzymatic inhibitors led to enhanced cryptococcal killing. Electron microscopy revealed structural changes and ruptured cryptococcal cell walls following treatment. Finally, additional studies demonstrated that osmotic lysis was responsible for cryptococcal death.

  19. Optimizing dendritic cell-based immunotherapy for cancer.

    PubMed

    Zhong, Hua; Shurin, Michael R; Han, Baohui

    2007-06-01

    Dendritic cells (DCs) are the most powerful professional antigen-presenting cells and are unique in their capability to initiate, maintain and regulate the intensity of primary immune responses, including specific antitumor responses. Development of practical procedures to prepare sufficient numbers of functional human DCs in culture from the peripheral blood precursors, paved the way for clinical trials to evaluate various DC-based strategies in patients with malignant diseases. However, no definite conclusions regarding the clinical and even immunological efficacy of DC vaccination can be stated, despite the fact that 12 years have passed since the first clinical trial utilizing DCs in cancer patients. Many unanswered questions hamper the development of DC-based vaccines, including the source of DC preparation and protocols for DC generation, activation and loading with tumor antigens, source of tumor antigens, route of vaccine administration and methods of immunomonitoring. Fortunately, in spite of the many obstacles, DC vaccines continue to hold promise for cancer therapy.

  20. 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.

  1. Engineered Lentivector Targeting of Dendritic Cells for In Vivo Immunization

    PubMed Central

    Yang, Lili; Yang, Haiguang; Rideout, Kendra; Cho, Taehoon; Joo, Kye il; Ziegler, Leslie; Elliot, Abigail; Walls, Anthony; Yu, Dongzi; Baltimore, David; Wang, Pin

    2008-01-01

    We report a method of inducing antigen production in dendritic cells (DCs) by in vivo targeting with lentiviral vectors that specifically bind to the DC surface protein, DC-SIGN. To target the DCs, the lentivector was enveloped with a viral glycoprotein from Sindbis virus, engineered to be DC-SIGN-specific. In vitro, this lentivector specifically transduced DCs and induced DC maturation. A remarkable frequency (up to 12%) of ovalbumin (OVA)-specific CD8+ T cells and a significant antibody response were observed 2 weeks following injection of a targeted lentiviral vector encoding an OVA transgene into naïve mice. These mice were solidly protected against the growth of the OVA-expressing E.G7 tumor and this methodology could even induce regression of an established tumor. Thus, lentiviral vectors targeting DCs provide a simple method of producing effective immunity and may provide an alternative route for immunization with protein antigens. PMID:18297056

  2. Optimizing Dendritic Cell-Based Approaches for Cancer Immunotherapy

    PubMed Central

    Datta, Jashodeep; Terhune, Julia H.; Lowenfeld, Lea; Cintolo, Jessica A.; Xu, Shuwen; Roses, Robert E.; Czerniecki, Brian J.

    2014-01-01

    Dendritic cells (DC) are professional antigen-presenting cells uniquely suited for cancer immunotherapy. They induce primary immune responses, potentiate the effector functions of previously primed T-lymphocytes, and orchestrate communication between innate and adaptive immunity. The remarkable diversity of cytokine activation regimens, DC maturation states, and antigen-loading strategies employed in current DC-based vaccine design reflect an evolving, but incomplete, understanding of optimal DC immunobiology. In the clinical realm, existing DC-based cancer immunotherapy efforts have yielded encouraging but inconsistent results. Despite recent U.S. Federal and Drug Administration (FDA) approval of DC-based sipuleucel-T for metastatic castration-resistant prostate cancer, clinically effective DC immunotherapy as monotherapy for a majority of tumors remains a distant goal. Recent work has identified strategies that may allow for more potent “next-generation” DC vaccines. Additionally, multimodality approaches incorporating DC-based immunotherapy may improve clinical outcomes. PMID:25506283

  3. Metabolic reprogramming in macrophages and dendritic cells in innate immunity

    PubMed Central

    Kelly, Beth; O'Neill, Luke AJ

    2015-01-01

    Activation of macrophages and dendritic cells (DCs) by pro-inflammatory stimuli causes them to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS), similar to the Warburg effect in tumors. However, it is only recently that the mechanisms responsible for this metabolic reprogramming have been elucidated in more detail. The transcription factor hypoxia-inducible factor-1α (HIF-1α) plays an important role under conditions of both hypoxia and normoxia. The withdrawal of citrate from the tricarboxylic acid (TCA) cycle has been shown to be critical for lipid biosynthesis in both macrophages and DCs. Interference with this process actually abolishes the ability of DCs to activate T cells. Another TCA cycle intermediate, succinate, activates HIF-1α and promotes inflammatory gene expression. These new insights are providing us with a deeper understanding of the role of metabolic reprogramming in innate immunity. PMID:26045163

  4. Deciphering the transcriptional network of the dendritic cell lineage.

    PubMed

    Miller, Jennifer C; Brown, Brian D; Shay, Tal; Gautier, Emmanuel L; Jojic, Vladimir; Cohain, Ariella; Pandey, Gaurav; Leboeuf, Marylene; Elpek, Kutlu G; Helft, Julie; Hashimoto, Daigo; Chow, Andrew; Price, Jeremy; Greter, Melanie; Bogunovic, Milena; Bellemare-Pelletier, Angelique; Frenette, Paul S; Randolph, Gwendalyn J; Turley, Shannon J; Merad, Miriam

    2012-09-01

    Although much progress has been made in the understanding of the ontogeny and function of dendritic cells (DCs), the transcriptional regulation of the lineage commitment and functional specialization of DCs in vivo remains poorly understood. We made a comprehensive comparative analysis of CD8(+), CD103(+), CD11b(+) and plasmacytoid DC subsets, as well as macrophage DC precursors and common DC precursors, across the entire immune system. Here we characterized candidate transcriptional activators involved in the commitment of myeloid progenitor cells to the DC lineage and predicted regulators of DC functional diversity in tissues. We identified a molecular signature that distinguished tissue DCs from macrophages. We also identified a transcriptional program expressed specifically during the steady-state migration of tissue DCs to the draining lymph nodes that may control tolerance to self tissue antigens.

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

    PubMed Central

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

    2013-01-01

    A complex role has been described for dendritic cells (DCs) in the potentiation and control of vascular inflammation and atherosclerosis. Resident vascular DCs are found in the intima of atherosclerosis-prone vascular regions exposed to disturbed blood flow patterns. Several phenotypically and functionally distinct vascular DC subsets have been described. The functional heterogeneity of these cells and their contributions to vascular homeostasis, inflammation, and atherosclerosis are only recently beginning to emerge. Here, we review the available literature, characterizing the origin and function of known vascular DC subsets and their important role contributing to the balance of immune activation and immune tolerance governing vascular homeostasis under healthy conditions. We then discuss how homeostatic DC functions are disrupted during atherogenesis, leading to atherosclerosis. The effectiveness of DC-based “atherosclerosis vaccine” therapies in the treatment of atherosclerosis is also reviewed. We further provide suggestions for distinguishing DCs from macrophages and discuss important future directions for the field. PMID:23552284

  6. Dendritic cell MST1 inhibits Th17 differentiation

    PubMed Central

    Li, Chunxiao; Bi, Yujing; Li, Yan; Yang, Hui; Yu, Qing; Wang, Jian; Wang, Yu; Su, Huilin; Jia, Anna; Hu, Ying; Han, Linian; Zhang, Jiangyuan; Li, Simin; Tao, Wufan; Liu, Guangwei

    2017-01-01

    Although the differentiation of CD4+T cells is widely studied, the mechanisms of antigen-presenting cell-dependent T-cell modulation are unclear. Here, we investigate the role of dendritic cell (DC)-dependent T-cell differentiation in autoimmune and antifungal inflammation and find that mammalian sterile 20-like kinase 1 (MST1) signalling from DCs negatively regulates IL-17 producing-CD4+T helper cell (Th17) differentiation. MST1 deficiency in DCs increases IL-17 production by CD4+T cells, whereas ectopic MST1 expression in DCs inhibits it. Notably, MST1-mediated DC-dependent Th17 differentiation regulates experimental autoimmune encephalomyelitis and antifungal immunity. Mechanistically, MST1-deficient DCs promote IL-6 secretion and regulate the activation of IL-6 receptor α/β and STAT3 in CD4+T cells in the course of inducing Th17 differentiation. Activation of the p38 MAPK signal is responsible for IL-6 production in MST1-deficient DCs. Thus, our results define the DC MST1–p38MAPK signalling pathway in directing Th17 differentiation. PMID:28145433

  7. The role of dendritic cells in CNS autoimmunity

    PubMed Central

    Zozulya, Alla L.; Clarkson, Benjamin D.; Ortler, Sonja; Fabry, Zsuzsanna

    2010-01-01

    Multiple sclerosis (MS) is a chronic immune-mediated, central nervous system (CNS) demyelinating disease. Clinical and histopathological features suggest an inflammatory etiology involving resident CNS innate cells as well as invading adaptive immune cells. Encephalitogenic myelin-reactive T cells have been implicated in the initiation of an inflammatory cascade, eventually resulting in demyelination and axonal damage (the histological hallmarks of MS). Dendritic cells (DC) have recently emerged as key modulators of this immunopathological cascade, as supported by studies in humans and experimental disease models. In one such model, experimental autoimmune encephalomyelitis (EAE), CNS microvessel-associated DC have been shown to be essential for local antigen recognition by myelin-reactive T cells. Moreover, the functional state and compartmental distribution of DC derived from CNS and associated lymphatics seem to be limiting factors in both the induction and effector phases of EAE. Moreover, DC modulate and balance the recruitment of encephalitogenic and regulatory T cells into CNS tissue. This capacity is critically influenced by DC surface expression of co-stimulatory or co-inhibitory molecules. The fact that DC accumulate in the CNS before T cells and can direct T-cell responses suggests that they are key determinants of CNS autoimmune outcomes. Here we provide a comprehensive review of recent advances in our understanding of CNS-derived DC and their relevance to neuroinflammation. PMID:20217033

  8. Uncoupling Dendrite Growth and Patterning: Single Cell Knockout Analysis of NMDA Receptor 2B

    PubMed Central

    Espinosa, J. Sebastian; Wheeler, Damian G.; Tsien, Richard W.; Luo, Liqun

    2009-01-01

    SUMMARY N-Methyl-D-aspartate receptors (NMDARs) play important functions in neural development. NR2B is the predominant NR2 subunit of NMDAR in the developing brain. Here we use MADM (Mosaic Analysis with Double Markers) to knock out NR2B in isolated single cells and analyze its cell-autonomous function in dendrite development. NR2B mutant dentate gyrus granule cells (dGCs) and barrel cortex layer 4 spiny stellate cells (bSCs) have similar dendritic growth rates, total length and branch number as control cells. However, mutant dGCs maintain supernumerary primary dendrites resulting from a pruning defect. Furthermore, while control bSCs restrict dendritic growth to a single barrel, mutant bSCs maintain dendritic growth in multiple barrels. Thus, NR2B functions cell-autonomously to regulate dendrite patterning to ensure that sensory information is properly represented in the cortex. Our study also indicates that molecular mechanisms that regulate activity-dependent dendrite patterning can be separated from those that control general dendrite growth and branching. PMID:19409266

  9. Uncoupling dendrite growth and patterning: single-cell knockout analysis of NMDA receptor 2B.

    PubMed

    Espinosa, J Sebastian; Wheeler, Damian G; Tsien, Richard W; Luo, Liqun

    2009-04-30

    N-methyl-D-aspartate receptors (NMDARs) play important functions in neural development. NR2B is the predominant NR2 subunit of NMDAR in the developing brain. Here we use mosaic analysis with double markers (MADM) to knock out NR2B in isolated single cells and analyze its cell-autonomous function in dendrite development. NR2B mutant dentate gyrus granule cells (dGCs) and barrel cortex layer 4 spiny stellate cells (bSCs) have similar dendritic growth rates, total length, and branch number as control cells. However, mutant dGCs maintain supernumerary primary dendrites resulting from a pruning defect. Furthermore, while control bSCs restrict dendritic growth to a single barrel, mutant bSCs maintain dendritic growth in multiple barrels. Thus, NR2B functions cell autonomously to regulate dendrite patterning to ensure that sensory information is properly represented in the cortex. Our study also indicates that molecular mechanisms that regulate activity-dependent dendrite patterning can be separated from those that control general dendrite growth and branching.

  10. Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

    DTIC Science & Technology

    2014-07-01

    by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy PRINCIPAL INVESTIGATOR: David J. Chung, MD, PhD...5a. CONTRACT NUMBER Evaluation of Immune Responses Mediated by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine...ABSTRACT The purpose of this project is to study the immunomodulatory effect of Listeria on human dendritic cells (DCs) to optimize Listeria - based

  11. Tracking stem cells using magnetic nanoparticles

    PubMed Central

    Cromer Berman, Stacey M.; Walczak, Piotr; Bulte, Jeff W.M.

    2011-01-01

    Stem cell therapies offer great promise for many diseases, especially those without current effective treatments. It is believed that noninvasive imaging techniques, which offer the ability to track the status of cells after transplantation, will expedite progress in this field and help to achieve maximized therapeutic effect. Today’s biomedical imaging technology allows for real-time, noninvasive monitoring of grafted stem cells including their biodistribution, migration, survival, and differentiation, with magnetic resonance imaging (MRI) of nanoparticle-labeled cells being one of the most commonly used techniques. Among the advantages of MR cell tracking are its high spatial resolution, no exposure to ionizing radiation, and clinical applicability. In order to track cells by MRI, the cells need to be labeled with magnetic nanoparticles, for which many types exist. There are several cellular labeling techniques available, including simple incubation, use of transfection agents, magnetoelectroporation, and magnetosonoporation. In this overview article, we will review the use of different magnetic nanoparticles and discuss how these particles can be used to track the distribution of transplanted cells in different organ systems. Caveats and limitations inherent to the tracking of nanoparticle-labeled stem cells are also discussed. PMID:21472999

  12. 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

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

    EPA Science Inventory

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

  14. Altered heme-mediated modulation of dendritic cell function in sickle cell alloimmunization

    PubMed Central

    Godefroy, Emmanuelle; Liu, Yunfeng; Shi, Patricia; Mitchell, W. Beau; Cohen, Devin; Chou, Stella T.; Manwani, Deepa; Yazdanbakhsh, Karina

    2016-01-01

    Transfusions are the main treatment for patients with sickle cell disease. However, alloimmunization remains a major life-threatening complication for these patients, but the mechanism underlying pathogenesis of alloimmunization is not known. Given the chronic hemolytic state characteristic of sickle cell disease, resulting in release of free heme and activation of inflammatory cascades, we tested the hypothesis that anti-inflammatory response to heme is compromised in alloimmunized sickle patients, increasing their risk of alloimmunization. Heme-exposed monocyte-derived dendritic cells from both non-alloimmunized sickle patients and healthy donors inhibited priming of pro-inflammatory CD4+ type 1 T cells, and exhibited significantly reduced levels of the maturation marker CD83. In contrast, in alloimmunized patients, heme did not reverse priming of pro-inflammatory CD4+ cells by monocyte-derived dendritic cells or their maturation. Furthermore, heme dampened NF-κB activation in non-alloimmunized, but not in alloimmunized monocyte-derived dendritic cells. Heme-mediated CD83 inhibition depended on Toll-like receptor 4 but not heme oxygenase 1. These data suggest that extracellular heme limits CD83 expression on dendritic cells in non-alloimmunized sickle patients through a Toll-like receptor 4-mediated pathway, involving NF-κB, resulting in dampening of pro-inflammatory responses, but that in alloimmunized patients this pathway is defective. This opens up the possibility of developing new therapeutic strategies to prevent sickle cell alloimmunization. PMID:27229712

  15. Stem cell tracking using iron oxide nanoparticles.

    PubMed

    Bull, Elizabeth; Madani, Seyed Yazdan; Sheth, Roosey; Seifalian, Amelia; Green, Mark; Seifalian, Alexander M

    2014-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are an exciting advancement in the field of nanotechnology. They expand the possibilities of noninvasive analysis and have many useful properties, making them potential candidates for numerous novel applications. Notably, they have been shown that they can be tracked by magnetic resonance imaging (MRI) and are capable of conjugation with various cell types, including stem cells. In-depth research has been undertaken to establish these benefits, so that a deeper level of understanding of stem cell migratory pathways and differentiation, tumor migration, and improved drug delivery can be achieved. Stem cells have the ability to treat and cure many debilitating diseases with limited side effects, but a main problem that arises is in the noninvasive tracking and analysis of these stem cells. Recently, researchers have acknowledged the use of SPIONs for this purpose and have set out to establish suitable protocols for coating and attachment, so as to bring MRI tracking of SPION-labeled stem cells into common practice. This review paper explains the manner in which SPIONs are produced, conjugated, and tracked using MRI, as well as a discussion on their limitations. A concise summary of recently researched magnetic particle coatings is provided, and the effects of SPIONs on stem cells are evaluated, while animal and human studies investigating the role of SPIONs in stem cell tracking will be explored.

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

    PubMed Central

    Robak, E; Smolewski, P; Woźniacka, A; Sysa-Jedrzejowska, A; Robak, T

    2004-01-01

    Dendritic cells are a complex group of mainly bone-marrow-derived leukocytes that play a role in autoimmune diseases. The total number of circulating dendritic cells (tDC), and their plasmacytoid dendritic cell (pDC) and myeloid dendritic cell (mDC1 and mDC2) subpopulations were assessed using flow cytometry. The number of tDC and their subsets were significantly lower in systemic lupus erythematosus patients than in the control group. The count of tDC and their subsets correlated with the number of T cells. The number of tDC and pDC subpopulation were lower in the patients with lymphopenia and leukopenia than in the patients without these symptoms. Our data suggest that fluctuations in blood dendritic cell count in systemic lupus erythematosus patients are much more significant in pDC than in mDC, what may be caused by their migration to the sites of inflammation including skin lesions. Positive correlation between dendritic cell number and TCD4+, TCD8+ and CD19+ B cells, testify of their interactions and influence on SLE pathogenesis. The association between dendritic cell number and clinical features seems to be less clear. PMID:15223608

  17. Dendritic cell-based immunotherapy for cancer and relevant challenges for transfusion medicine.

    PubMed

    Voss, Ching Y; Albertini, Mark R; Malter, James S

    2004-07-01

    The encouraging results from dendritic cell-related cancer immunotherapy have created tremendous interest for its broad clinical application. Dendritic cells are the most potent antigen-presenting cells. In cancer patients, dendritic cell production and function along with other antitumor immune defenses are compromised. Autologous dendritic cells enriched and sensitized in vitro with tumor-associated antigens can effectively elicit host cellular immunity against cancer and result in clinical antitumor responses through either direct injection or ex vivo generation of antitumor T lymphocytes. In small group studies, clinical response rates have reached 50% in patients with advanced stage of cancer. These cellular products caused minimal side effects and were well tolerated. The isolation and preparation of clinical grade dendritic cells have been driven by transfusion medicine specialists who are well versed in similar processes for hematopoietic stem-cell preparation. The purpose of this article is to review the mechanisms of tumor immune surveillance and the biology of dendritic cells relevant to tumor antigen presentation, sensitization, and T-lymphocyte stimulation. Information on tumor-associated antigens and clinical trial results with dendritic cell-based cancer immunotherapy are summarized. The potential challenges for blood banking/transfusion medicine involving both technical and regulatory issues are discussed.

  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. 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

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

    PubMed Central

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

    2016-01-01

    Antithymocyte globulin (ATG) is used in the prevention of graft-versus-host disease during allogeneic hematopoietic stem cell transplantation. It is generally accepted that ATG mediates its immunosuppressive effect primarily via depletion of T cells. Here, we analyzed the impact of ATG-Fresenius (now Grafalon®) on human monocyte-derived dendritic cells (DC). ATG induced a semi-mature phenotype in DC with significantly reduced expression of CD14, increased expression of HLA-DR, and intermediate expression of CD54, CD80, CD83, and CD86. ATG-DC showed an increase in IL-10 secretion but no IL-12 production. In line with this tolerogenic phenotype, ATG caused a significant induction of indoleamine 2,3-dioxygenase expression and a concomitant increase in levels of tryptophan metabolites in the supernatants of DC. Further, ATG-DC did not induce the proliferation of allogeneic T cells in a mixed lymphocyte reaction but actively suppressed the T cell proliferation induced by mature DC. These data suggest that besides its well-known effect on T cells, ATG modulates the phenotype of DC in a tolerogenic way, which might constitute an essential part of its immunosuppressive action in vivo. PMID:27973435

  1. Follicular Dendritic Cells Emerge from Ubiquitous Perivascular Precursors

    PubMed Central

    Krautler, Nike Julia; Kana, Veronika; Kranich, Jan; Tian, Yinghua; Perera, Dushan; Lemm, Doreen; Schwarz, Petra; Armulik, Annika; Browning, Jeffrey L.; Tallquist, Michelle; Buch, Thorsten; Oliveira-Martins, José B.; Zhu, Caihong; Hermann, Mario; Wagner, Ulrich; Brink, Robert; Heikenwalder, Mathias; Aguzzi, Adriano

    2013-01-01

    Summary The differentiation of follicular dendritic cells (FDC) is essential to the remarkable microanatomic plasticity of lymphoid follicles. Here we show that FDC arise from ubiquitous perivascular precursors (preFDC) expressing platelet-derived growth factor receptor β (PDGFRβ). PDGFRβ-Cre-driven reporter gene recombination resulted in FDC labeling, whereas conditional ablation of PDGFRβ+-derived cells abolished FDC, indicating that FDC originate from PDGFRβ+ cells. Lymphotoxin-α-overexpressing prion protein (PrP)+ kidneys developed PrP+ FDC after transplantation into PrP mice, confirming that preFDC exist outside lymphoid organs. Adipose tissue-derived PDGFRβ+ stromal-vascular cells responded to FDC maturation factors and, when transplanted into lymphotoxin β receptor (LTβR) kidney capsules, differentiated into Mfge8+CD21/35+ FcγRIIβ+PrP+ FDC capable of trapping immune complexes and recruiting B cells. Spleens of lymphocyte-deficient mice contained perivascular PDGFRβ+ FDC precursors whose expansion required both lymphoid tissue inducer (LTi) cells and lymphotoxin. The ubiquity of preFDC and their strategic location at blood vessels may explain the de novo generation of organized lymphoid tissue at sites of lymphocytic inflammation. PMID:22770220

  2. Hypergravity Effects on Dendritic Cells and Vascular Wall Interactions

    NASA Astrophysics Data System (ADS)

    Bellik, L.; Parenti, A.; Ledda, F.; Basile, V.; Romano, G.; Fusi, F.; Monici, M.

    2009-01-01

    Dendritic cells (DCs), the most potent antigen-presenting cells inducing specific immune responses, are involved in the pathogenesis of atherosclerosis. In this inflammatory disease, DCs increase in number, being particularly abundant in the shoulder regions of plaques. Since the exposure to altered gravitational conditions results in a significant impairment of the immune function, the aim of this study was to investigate the effects of hypergravity on both the function of DCs and their interactions with the vascular wall cells. Monocytes from peripheral blood mononuclear cells of healthy volunteers were sorted by CD14+ magnetic beads selection, cultured for 6 days in medium supplemented with GM-CSF and IL-4, followed by a further maturation stimulus. DC phenotype, assessed by flow cytometry, showed a high expression of the specific DC markers CD80, CD86, HLA-DR and CD83. The DCs obtained were then exposed to hypergravitational stimuli and their phenotype, cytoskeleton, ability to activate lymphocytes and interaction with vascular wall cells were investigated. The findings showed that the exposure to hypergravity conditions resulted in a significant impairment of DC cytoskeletal organization, without affecting the expression of DC markers. Moreover, an increase in DC adhesion to human vascular smooth muscle cells and in their ability to activate lymphocytes was observed.

  3. 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

  4. Dendritic Cell-Mediated In Vivo Bone Resorption

    PubMed Central

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

    2013-01-01

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

  5. Defining human dendritic cell progenitors by multiparametric flow cytometry

    PubMed Central

    Breton, Gaëlle; Lee, Jaeyop; Liu, Kang; Nussenzweig, Michel C

    2015-01-01

    Human dendritic cells (DCs) develop from progressively restricted bone marrow (BM) progenitors: these progenitor cells include granulocyte, monocyte and DC progenitor (GMDP) cells; monocyte and DC progenitor (MDP) cells; and common DC progenitor (CDP) and DC precursor (pre-DC) cells. These four DC progenitors can be defined on the basis of the expression of surface markers such as CD34 and hematopoietin receptors. In this protocol, we describe five multiparametric flow cytometry panels that can be used as a tool (i) to simultaneously detect or phenotype the four DC progenitors, (ii) to isolate DC progenitors to enable in vitro differentiation or (iii) to assess the in vitro differentiation and proliferation of DC progenitors. The entire procedure from isolation of cells to flow cytometry can be completed in 3–7 h. This protocol provides optimized antibody panels, as well as gating strategies, for immunostaining of BM and cord blood specimens to study human DC hematopoiesis in health, disease and vaccine settings. PMID:26292072

  6. Dendritic cell targeted vaccines: Recent progresses and challenges

    PubMed Central

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

    2016-01-01

    ABSTRACT Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches. PMID:26513200

  7. Aging and the Dendritic Cell System: Implications for Cancer

    PubMed Central

    Shurin, Michael R.; Shurin, Galina V.; Chatta, Gurkamal S.

    2007-01-01

    The immune system shows a decline in responsiveness to antigens both with aging, as well as in the presence of tumors. The malfunction of the immune system with age can be attributed to developmental and functional alterations in several cell populations. Previous studies have shown defects in humoral responses and abnormalities in T cell function in aged individuals, but have not distinguished between abnormalities in antigen presentation and intrinsic T cell or B cell defects in aged individuals. Dendritic cells (DC) play a pivotal role in regulating immune responses by presenting antigens to naïve T lymphocytes, modulating Th1/Th2/Treg balance, producing numerous regulatory cytokines and chemokines, and modifying survival of immune effectors. DC are receiving increased attention due to their involvement in the immunobiology of tolerance and autoimmunity, as well as their potential role as biological adjuvants in tumor vaccines. Recent advances in the molecular and cell biology of different DC populations allow for addressing the issue of DC and aging both in rodents and humans. Since DC play a crucial role in initiating and regulating immune responses, it is reasonable to hypothesize that they are directly involved in altered antitumor immunity in aging. However, the results of studies focusing on DC in the elderly are conflicting. The present review summarizes the available human and experimental animal data on quantitative and qualitative alterations of DC in aging and discusses the potential role of the DC system in the increased incidence of cancer in the elderly. PMID:17446082

  8. 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

  9. Maturing dendritic cells depend on RAGE for in vivo homing to lymph nodes.

    PubMed

    Manfredi, Angelo A; Capobianco, Annalisa; Esposito, Antonio; De Cobelli, Francesco; Canu, Tamara; Monno, Antonella; Raucci, Angela; Sanvito, Francesca; Doglioni, Claudio; Nawroth, Peter P; Bierhaus, Angelika; Bianchi, Marco E; Rovere-Querini, Patrizia; Del Maschio, Alessandro

    2008-02-15

    The mobilization of dendritic cells (DCs) from peripheral tissues is critical for the establishment of T cell-dependent immune responses or tolerance, because the physical interaction of DCs with naive T cells takes place in the T cell areas of lymph nodes. The autocrine/paracrine release of the high mobility group box 1 (HMGB1) nuclear protein by DCs controls the outcome of the DC-T cell interaction, influencing the priming/Th1 polarization of naive T cells. We herein present evidence that the receptor for advanced glycation end products (RAGE), a multiligand member of the Ig superfamily of cell-surface molecules that acts as a receptor for HMGB1, plays a nonredundant role in DC homing to lymph nodes. We used noninvasive imaging by magnetic resonance and immunohistochemistry to track DCs after s.c. injection in the footpad of wild-type(+/+) or RAGE(-/-) mice. Maturing DCs expressing RAGE effectively migrated in both conditions. In contrast, RAGE(-/-) DCs failed to reach the draining popliteal lymph nodes of +/+ and -/- mice, indicating that the integrity of RAGE is required for DC mobilization. Thus the HMGB1-RAGE pathway is a checkpoint in DC maturation and function and a candidate for targeted therapies.

  10. 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

  11. Designing vaccines based on biology of human dendritic cell subsets

    PubMed Central

    Palucka, Karolina; Banchereau, Jacques; Mellman, Ira

    2010-01-01

    The effective vaccines developed against a variety of infectious agents, including polio, measles and Hepatitis B, represent major achievements in medicine. These vaccines, usually composed of microbial antigens, are often associated with an adjuvant that activates dendritic cells (DCs). Many infectious diseases are still in need of an effective vaccine including HIV, malaria, hepatitis C and tuberculosis. In some cases, the induction of cellular rather than humoral responses may be more important as the goal is to control and eliminate the existing infection rather than to prevent it. Our increased understanding of the mechanisms of antigen presentation, particularly with the description of DC subsets with distinct functions, as well as their plasticity in responding to extrinsic signals, represent opportunities to develop novel vaccines. In addition, we foresee that this increased knowledge will permit us to design vaccines that will reprogram the immune system to intervene therapeutically in cancer, allergy and autoimmunity. PMID:21029958

  12. Increased plasmacytoid dendritic cells in Guillain-Barré syndrome.

    PubMed

    Wang, Yu-Zhong; Feng, Xun-Gang; Wang, Qian; Xing, Chun-Ye; Shi, Qi-Guang; Kong, Qing-Xia; Cheng, Pan-Pan; Zhang, Yong; Hao, Yan-Lei; Yuki, Nobuhiro

    2015-06-15

    Guillain-Barré syndrome (GBS) is a post-infectious autoimmune disease. Dendritic cells (DCs) can recognize the pathogen and modulate the host immune response. Exploring the role of DCs in GBS will help our understanding of the disease development. In this study, we aimed to analyze plasmacytoid and conventional DCs in peripheral blood of patients with GBS at different stages of the disease: acute phase as well as early and late recovery phases. There was a significant increase of plasmacytoid DCs in the acute phase (p=0.03 vs healthy donors). There was a positive correlation between percentage of plasmacytoid DCs and the clinical severity of patients with GBS (r=0.61, p<0.001). Quantitative polymerase chain reaction and flow cytometry confirmed the aberrant plasmacytoid DCs in GBS. Thus, plasmacytoid DCs may participate in the development of GBS.

  13. New generation of oral mucosal vaccines targeting dendritic cells

    PubMed Central

    Owen, Jennifer L.; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-01-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including B. anthracis in experimental models of disease. PMID:23835515

  14. New generation of oral mucosal vaccines targeting dendritic cells.

    PubMed

    Owen, Jennifer L; Sahay, Bikash; Mohamadzadeh, Mansour

    2013-12-01

    As most infectious organisms gain entry at mucosal surfaces, there is a great deal of interest in developing vaccines that elicit effective mucosal immune responses against pathogen challenge. Targeted vaccination is one of the most effective methods available to prevent and control infectious diseases. Mucosal vaccines can offer lower costs, better accessibility, needle free delivery, and a higher capacity for mass immunizations during pandemics. Both local mucosal immunity and robust systemic responses can be achieved through mucosal vaccination. Recent progress in understanding the molecular and cellular components of the mucosal immune system have allowed for the development of a novel mucosal vaccine platform utilizing specific dendritic cell-targeting peptides and orally administered lactobacilli to elicit efficient antigen specific immune responses against infections, including Bacillus anthracis in experimental models of disease.

  15. Differential functional effects of biomaterials on dendritic cell maturation.

    PubMed

    Park, Jaehyung; Babensee, Julia E

    2012-10-01

    The immunological outcome of dendritic cell (DC) treatment with different biomaterials was assessed to demonstrate the range of DC phenotypes induced by biomaterials commonly used in combination products. Immature DCs (iDCs) were derived from human peripheral blood monocytes, and treated with different biomaterial films of alginate, agarose, chitosan, hyaluronic acid (HA), or 75:25 poly(lactic-co-glycolic acid) (PLGA) and a comprehensive battery of phenotypic functional outcomes was assessed. Different levels of functional changes in DC phenotype were observed depending on the type of biomaterial films used to treat the DCs. Treatment of DCs with PLGA or chitosan films supported DC maturation, with higher levels of DC allostimulatory capacity, pro-inflammatory cytokine release, and expression of CD80, CD86, CD83, HLA-DQ and CD44 compared with iDCs, and lower endocytic ability compared with iDCs. Alginate film induced pro-inflammatory cytokine release from DCs at levels higher than from iDCs. Dendritic cells treated with HA film expressed lower levels of CD40, CD80, CD86 and HLA-DR compared with iDCs. They also exhibited lower endocytic ability and CD44 expression than iDCs, possibly due to an insolubilized (cross-linked) form of high molecular weight HA. Interestingly, treatment of DCs with agarose film maintained the DC functional phenotype at levels similar to iDCs except for CD44 expression, which was lower than that of iDCs. Taken together, these results can provide selection criteria for biomaterials to be used in immunomodulating applications and can inform potential outcomes of biomaterials within combination products on associated immune responses as desired by the application.

  16. Role of Dendritic Cells in the Pathogenesis of Whipple's Disease

    PubMed Central

    Schinnerling, Katina; Geelhaar-Karsch, Anika; Allers, Kristina; Friebel, Julian; Conrad, Kristina; Loddenkemper, Christoph; Kühl, Anja A.; Erben, Ulrike; Ignatius, Ralf; Schneider, Thomas

    2014-01-01

    Accumulation of Tropheryma whipplei-stuffed macrophages in the duodenum, impaired T. whipplei-specific Th1 responses, and weak secretion of interleukin-12 (IL-12) are hallmarks of classical Whipple's disease (CWD). This study addresses dendritic cell (DC) functionality during CWD. We documented composition, distribution, and functionality of DC ex vivo or after in vitro maturation by fluorescence-activated cell sorting (FACS) and by immunohistochemistry in situ. A decrease in peripheral DC of untreated CWD patients compared to healthy donors was due to reduced CD11chigh myeloid DC (M-DC). Decreased maturation markers CD83, CD86, and CCR7, as well as low IL-12 production in response to stimulation, disclosed an immature M-DC phenotype. In vitro-generated monocyte-derived DC from CWD patients showed normal maturation and T cell-stimulatory capacity under proinflammatory conditions but produced less IL-12 and failed to activate T. whipplei-specific Th1 cells. In duodenal and lymphoid tissues, T. whipplei was found within immature DC-SIGN+ DC. DC and proliferating lymphocytes were reduced in lymph nodes of CWD patients compared to levels in controls. Our results indicate that dysfunctional IL-12 production by DC provides suboptimal conditions for priming of T. whipplei-specific T cells during CWD and that immature DC carrying T. whipplei contribute to the dissemination of the bacterium. PMID:25385798

  17. Thrombin regulates the function of human blood dendritic cells

    SciTech Connect

    Yanagita, Manabu; Kobayashi, Ryohei; Kashiwagi, Yoichiro; Shimabukuro, Yoshio; Murakami, Shinya E-mail: ipshinya@dent.osaka-u.ac.jp

    2007-12-14

    Thrombin is the key enzyme in the coagulation cascade and activates endothelial cells, neutrophils and monocytes via protease-activated receptors (PARs). At the inflammatory site, immune cells have an opportunity to encounter thrombin. However little is known about the effect of thrombin for dendritic cells (DC), which are efficient antigen-presenting cells and play important roles in initiating and regulating immune responses. The present study revealed that thrombin has the ability to stimulate blood DC. Plasmacytoid DC (PDC) and myeloid DC (MDC) isolated from PBMC expressed PAR-1 and released MCP-1, IL-10, and IL-12 after thrombin stimulation. Unlike blood DC, monocyte-derived DC (MoDC), differentiated in vitro did not express PAR-1 and were unresponsive to thrombin. Effects of thrombin on blood DC were significantly diminished by the addition of anti-PAR-1 Ab or hirudin, serine protease inhibitor. Moreover, thrombin induced HLA-DR and CD86 expression on DC and the thrombin-treated DC induced allogenic T cell proliferation. These findings indicate that thrombin plays a role in the regulation of blood DC functions.

  18. Dendritic cells therapy confers a protective microenvironment in murine pregnancy.

    PubMed

    Miranda, S; Litwin, S; Barrientos, G; Szereday, L; Chuluyan, E; Bartho, J S; Arck, P C; Blois, S M

    2006-11-01

    The fetal-placental unit is a semi-allograft and immunological recognition of pregnancy, together with the subsequent response of the maternal immune system, is necessary for a successful pregnancy. Dendritic cells (DC) show a biological plasticity that confers them special characteristics regulating both immunity and tolerance. Therapy employing DC proved to diminish the abortion in the DBA/2J-mated CBA/J females; however, the underlying mechanisms remain unknown. Here, we evaluated whether DC therapy influences the presence of immunoregulatory populations of cells at the fetal-maternal interface. To address this hypothesis, we analysed the pregnancy-protective CD8, gammadelta cell populations as well as transforming growth factor (TGF)-beta1 and progesterone-induced blocking factor (PIBF) expression at the fetal-maternal interface from abortion-prone female mice that had previously received adoptive transfer of syngeneic DC. Syngeneic DC therapy induced an increase in the number of CD8 and gammadelta cells. Additionally, an upregulation of TGF-beta1 and PIBF expression could be detected after DC transfer. We suggest that DC therapy differentially upregulates a regulatory/protective population of cells at the fetal-maternal interface. It is reasonable to assure that this mechanism would be responsible for the lower abortion rate.

  19. Probiotic modulation of dendritic cell function is influenced by ageing.

    PubMed

    You, Jialu; Dong, Honglin; Mann, Elizabeth R; Knight, Stella C; Yaqoob, Parveen

    2014-02-01

    Dendritic cells (DCs) are critical for the generation of T-cell responses. DC function may be modulated by probiotics, which confer health benefits in immunocompromised individuals, such as the elderly. This study investigated the effects of four probiotics, Bifidobacterium longum bv. infantis CCUG 52486, B. longum SP 07/3, Lactobacillus rhamnosus GG (L.GG) and L. casei Shirota (LcS), on DC function in an allogeneic mixed leucocyte reaction (MLR) model, using DCs and T-cells from young and older donors in different combinations. All four probiotics enhanced expression of CD40, CD80 and CCR7 on both young and older DCs, but enhanced cytokine production (TGF-β, TNF-α) by old DCs only. LcS induced IL-12 and IFNγ production by DC to a greater degree than other strains, while B. longum bv. infantis CCUG 52486 favoured IL-10 production. Stimulation of young T cells in an allogeneic MLR with DC was enhanced by probiotic pretreatment of old DCs, which demonstrated greater activation (CD25) than untreated controls. However, pretreatment of young or old DCs with LPS or probiotics failed to enhance the proliferation of T-cells derived from older donors. In conclusion, this study demonstrates that ageing increases the responsiveness of DCs to probiotics, but this is not sufficient to overcome the impact of immunosenescence in the MLR.

  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 differentiation of cerebellar Purkinje cells is promoted by ryanodine receptors expressed by Purkinje and granule cells.

    PubMed

    Ohashi, Ryo; Sakata, Shin-ichi; Naito, Asami; Hirashima, Naohide; Tanaka, Masahiko

    2014-04-01

    Cerebellar Purkinje cells have the most elaborate dendritic trees among neurons in the brain. We examined the roles of ryanodine receptor (RyR), an intracellular Ca(2+) release channel, in the dendrite formation of Purkinje cells using cerebellar cell cultures. In the cerebellum, Purkinje cells express RyR1 and RyR2, whereas granule cells express RyR2. When ryanodine (10 µM), a blocker of RyR, was added to the culture medium, the elongation and branching of Purkinje cell dendrites were markedly inhibited. When we transferred small interfering RNA (siRNA) against RyR1 into Purkinje cells using single-cell electroporation, dendritic branching but not elongation of the electroporated Purkinje cells was inhibited. On the other hand, transfection of RyR2 siRNA into granule cells also inhibited dendritic branching of Purkinje cells. Furthermore, ryanodine reduced the levels of brain-derived neurotrophic factor (BDNF) in the culture medium. The ryanodine-induced inhibition of dendritic differentiation was partially rescued when BDNF was exogenously added to the culture medium in addition to ryanodine. Overall, these results suggest that RyRs expressed by both Purkinje and granule cells play important roles in promoting the dendritic differentiation of Purkinje cells and that RyR2 expressed by granule cells is involved in the secretion of BDNF from granule cells.

  2. In vivo cell tracking with bioluminescence imaging.

    PubMed

    Kim, Jung Eun; Kalimuthu, Senthilkumar; Ahn, Byeong-Cheol

    2015-03-01

    Molecular imaging is a fast growing biomedical research that allows the visual representation, characterization and quantification of biological processes at the cellular and subcellular levels within intact living organisms. In vivo tracking of cells is an indispensable technology for development and optimization of cell therapy for replacement or renewal of damaged or diseased tissue using transplanted cells, often autologous cells. With outstanding advantages of bioluminescence imaging, the imaging approach is most commonly applied for in vivo monitoring of transplanted stem cells or immune cells in order to assess viability of administered cells with therapeutic efficacy in preclinical small animal models. In this review, a general overview of bioluminescence is provided and recent updates of in vivo cell tracking using the bioluminescence signal are discussed.

  3. Novel immunomodulatory effects of adiponectin on dendritic cell functions.

    PubMed

    Tsang, Julia Yuen Shan; Li, Daxu; Ho, Derek; Peng, Jiao; Xu, Aimin; Lamb, Jonathan; Chen, Yan; Tam, Paul Kwong Hang

    2011-05-01

    Adiponectin (ADN) is an adipocytokine with anti-inflammatory properties. Although it has been reported that ADN can inhibit the immunostimulatory function of monocytes and macrophages, little is known of its effect on dendritic cells (DC). Recent data suggest that ADN can regulate immune responses. DCs are uniquely specialised antigen presenting cells that play a central role in the initiation of immunity and tolerance. In this study, we have investigated the immuno- modulatory effects of ADN on DC functions. We found that ADN has only moderate effect on the differentiation of murine bone marrow (BM) derived DCs but altered the phenotype of DCs. The expression of major histocompatibilty complex class II (MHCII), CD80 and CD86 on ADN conditioned DCs (ADN-DCs) was lower than that on untreated cells. The production of IL-12p40 was also suppressed in ADN-DCs. Interestingly, ADN treated DCs showed an increase in the expression of the inhibitory molecule, programmed death-1 ligand (PDL-1) compared to untreated cells. In vitro co-culture of ADN-DCs with allogeneic T cells led to a decrease in T cell proliferation and reduction of IL-2 production. Concomitant with that, a higher percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) was detected in co-cultures of T cells and ADN-DCs. Blocking PD-1/PDL-1 pathway could partially restore T cell function. These findings suggest that the immunomodulatory effect of ADN on immune responses could be at least partially be mediated by its ability to alter DC function. The PD-1/PDL-1 pathway and the enhancement of Treg expansion are implicated in the immunomodulatory mechanisms.

  4. Regulation of Neonatal Development of Retinal Ganglion Cell Dendrites by Neurotrophin-3 Overexpression

    PubMed Central

    Liu, Xiaorong; Robinson, Michael L.; Schreiber, Ann Marie; Wu, Vincent; LaVail, Matthew M.; Cang, Jianhua; Copenhagen, David R.

    2009-01-01

    The morphology of dendrites constrains and reflects the nature of synaptic inputs to neurons. The visual system has served as a useful model to show how visual function is determined by the arborization patterns of neuronal processes. In retina, light ON and light OFF responding ganglion cells selectively elaborate their dendritic arbors in distinct sublamina, where they receive, respectively, inputs from ON and OFF bipolar cells. During neonatal maturation, the bi-laminarly distributed dendritic arbors of ON-OFF RGCs are refined to more narrowly localized monolaminar structures characteristic of ON or OFF RGCs. Recently, brain-derived neurotrophic factor (BDNF) has been shown to regulate this laminar refinement, and, additionally, to enhance the development of dendritic branches selectively of ON RGCs. Although other related neurotrophins are known to regulate neuronal process formation in the central nervous system, little is known about their action in maturing retina. Here, we report that overexpression of neurotrophin-3 (NT-3) in the eye accelerates RGC laminar refinement before eye opening. Furthermore, NT-3 overexpression increases dendritic branch number but reduces dendritic elongation preferentially in ON-OFF RGCs, a process that also occurs before eye opening. NT-3 overexpression does affect dendritic maturation in ON RGCs, but to a much less degree. Taken together, our results suggest that NT-3 and BDNF exhibit overlapping effects in laminar refinement but distinct RGC-cell-type specific effects in shaping dendritic arborization during postnatal development. PMID:19350645

  5. 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.

  6. Dendritic cells in hyperplastic thymuses from patients with myasthenia gravis.

    PubMed

    Nagane, Yuriko; Utsugisawa, Kimiaki; Obara, Daiji; Yamagata, Munehisa; Tohgi, Hideo

    2003-05-01

    To investigate the role of dendritic cells (DCs) in the hyperplastic myasthenia gravis (MG) thymus, we studied the frequency and distribution of three mature DC phenotypes (CD83(+)CD11c(+), CD86(+)CD11c(+), and HLA-DR(+)CD11c(+)) in samples from patients with MG whose symptoms dramatically improved following thymectomy and in non-MG control thymuses. In hyperplastic MG thymuses, mature DCs were much more numerous in nonmedullary areas, such as the subcapsular/outer cortex; around the germinal centers; and in extralobular connective tissue, particularly around blood vessels. Mature DCs strongly coexpressed CD44 and appeared to be components of a CD44-highly positive (CD44(high)) cell population migrating from the vascular system. Furthermore, in the hyperplastic MG thymus, the expression of secondary lymphoid-tissue chemokine (SLC) markedly increased especially around extralobular blood vessels, where the CD44(high) cell population accumulated. These findings suggest that DCs may migrate into the hyperplastic thymus from the vascular system via mechanisms that involve CD44 and SLC. DCs may present self-antigens, thereby promoting the priming and/or boosting of potentially autoreactive T cells against the acetylcholine receptor.

  7. Immunogenicity is preferentially induced in sparse dendritic cell cultures

    PubMed Central

    Nasi, Aikaterini; Bollampalli, Vishnu Priya; Sun, Meng; Chen, Yang; Amu, Sylvie; Nylén, Susanne; Eidsmo, Liv; Rothfuchs, Antonio Gigliotti; Réthi, Bence

    2017-01-01

    We have previously shown that human monocyte-derived dendritic cells (DCs) acquired different characteristics in dense or sparse cell cultures. Sparsity promoted the development of IL-12 producing migratory DCs, whereas dense cultures increased IL-10 production. Here we analysed whether the density-dependent endogenous breaks could modulate DC-based vaccines. Using murine bone marrow-derived DC models we show that sparse cultures were essential to achieve several key functions required for immunogenic DC vaccines, including mobility to draining lymph nodes, recruitment and massive proliferation of antigen-specific CD4+ T cells, in addition to their TH1 polarization. Transcription analyses confirmed higher commitment in sparse cultures towards T cell activation, whereas DCs obtained from dense cultures up-regulated immunosuppressive pathway components and genes suggesting higher differentiation plasticity towards osteoclasts. Interestingly, we detected a striking up-regulation of fatty acid and cholesterol biosynthesis pathways in sparse cultures, suggesting an important link between DC immunogenicity and lipid homeostasis regulation. PMID:28276533

  8. Targeting Dendritic Cell Function during Systemic Autoimmunity to Restore Tolerance

    PubMed Central

    Mackern-Oberti, Juan P.; Vega, Fabián; Llanos, Carolina; Bueno, Susan M.; Kalergis, Alexis M.

    2014-01-01

    Systemic autoimmune diseases can damage nearly every tissue or cell type of the body. Although a great deal of progress has been made in understanding the pathogenesis of autoimmune diseases, current therapies have not been improved, remain unspecific and are associated with significant side effects. Because dendritic cells (DCs) play a major role in promoting immune tolerance against self-antigens (self-Ags), current efforts are focusing at generating new therapies based on the transfer of tolerogenic DCs (tolDCs) during autoimmunity. However, the feasibility of this approach during systemic autoimmunity has yet to be evaluated. TolDCs may ameliorate autoimmunity mainly by restoring T cell tolerance and, thus, indirectly modulating autoantibody development. In vitro induction of tolDCs loaded with immunodominant self-Ags and subsequent cell transfer to patients would be a specific new therapy that will avoid systemic immunosuppression. Herein, we review recent approaches evaluating the potential of tolDCs for the treatment of systemic autoimmune disorders. PMID:25229821

  9. 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

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

    PubMed

    Pietrella, Donatella; Bistoni, Giovanni; Corbucci, Cristina; Perito, Stefano; Vecchiarelli, Anna

    2006-04-01

    Cell wall components of fungi involved in induction of host immune response are predominantly proteins and glycoproteins, the latter being mainly mannoproteins (MP). In this study we analyse the interaction of the MP from Candida albicans (MP65) with dendritic cells (DC) and demonstrate that MP65 stimulates DC and induces the release of TNF-alpha, IL-6 and the activation of IL-12 gene, with maximal value 6 h post treatment. MP65 induces DC maturation by increasing costimulatory molecules and decreasing CD14 and FcgammaR molecule expression. The latter effect is partly mediated by toll-like receptor 2 (TLR2) and TLR4, and the MyD88-dependent pathway is involved in the process. MP65 enables DC to activate T cell response, its protein core is essential for induction of T cell activation, while its glycosylated portion primarily promotes cytokine production. The mechanisms involved in induction of protective response against C. albicans could be mediated by the MP65 antigen, suggesting that MP65 may be a suitable candidate vaccine.

  11. 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.

  12. 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

  13. Software for precise tracking of cell proliferation

    SciTech Connect

    Kurokawa, Hiroshi; Noda, Hisayori; Sugiyama, Mayu; Sakaue-Sawano, Asako; Fukami, Kiyoko; Miyawaki, Atsushi

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer We developed software for analyzing cultured cells that divide as well as migrate. Black-Right-Pointing-Pointer The active contour model (Snakes) was used as the core algorithm. Black-Right-Pointing-Pointer The time backward analysis was also used for efficient detection of cell division. Black-Right-Pointing-Pointer With user-interactive correction functions, the software enables precise tracking. Black-Right-Pointing-Pointer The software was successfully applied to cells with fluorescently-labeled nuclei. -- Abstract: We have developed a multi-target cell tracking program TADOR, which we applied to a series of fluorescence images. TADOR is based on an active contour model that is modified in order to be free of the problem of locally optimal solutions, and thus is resistant to signal fluctuation and morphological changes. Due to adoption of backward tracing and addition of user-interactive correction functions, TADOR is used in an off-line and semi-automated mode, but enables precise tracking of cell division. By applying TADOR to the analysis of cultured cells whose nuclei had been fluorescently labeled, we tracked cell division and cell-cycle progression on coverslips over an extended period of time.

  14. 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

  15. Inflammatory pseudotumour-like follicular dendritic cell tumour of the spleen

    PubMed Central

    Nishiyama, Raisuke; Baba, Satoshi; Watahiki, Yoichi; Maruo, Hirotoshi

    2015-01-01

    We describe an unusual case of a 73-year-old woman presenting with a solitary splenic mass 8 cm in diameter and an elevation of serum soluble interleukin-2 receptor level. The preoperative diagnosis was primary malignant lymphoma of the spleen. Splenectomy was conducted. Histological analysis confirmed an inflammatory pseudotumour-like follicular dendritic cell tumour that showed different clinicopathological features from those of the classic follicular dendritic cell tumour. Only 33 cases of inflammatory pseudotumour-like follicular dendritic cell tumour have so far been reported. We discuss the incidence, presentation and management of this rare disease. PMID:25766434

  16. [Morphofunctional changes of dendritic cells induced by sulfated polysaccharides of brown algae].

    PubMed

    Makarenkova, I D; Akhmatova, N K; Ermakova, S P; Besednova, N N

    2017-01-01

    The effects of various sulfated polysaccharides of brown algae Fucus evanescens, Saccharina cichorioides and Saccharina japonica on the morphofunctional changes of dendritic cells have been investigated using flow cytometry and phase-contrast microscopy. The dendritic cells are characterized by larger sizes, vacuolated cytoplasm, eccentrically located nucleus, and also by the presence of numerous cytoplasmic pseudopodia of various shapes. They express surface markers, indicating their maturation (CD83, CD11c, HLA-DR, CD86). Increased production of immunoregulatory (IL-12) and proinflammatory TNF-a, IL-6) cytokines (by dendritic cells polarizes the development of the Th-1 type immune response.

  17. 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.

  18. RORα Regulates Multiple Aspects of Dendrite Development in Cerebellar Purkinje Cells In Vivo.

    PubMed

    Takeo, Yukari H; Kakegawa, Wataru; Miura, Eriko; Yuzaki, Michisuke

    2015-09-09

    The establishment of cell-type-specific dendritic arbors is fundamental for proper neural circuit formation. Here, using temporal- and cell-specific knock-down, knock-out, and overexpression approaches, we show that multiple aspects of the dendritic organization of cerebellar Purkinje cells (PCs) are controlled by a single transcriptional factor, retinoic acid-related orphan receptor-alpha (RORα), a gene defective in staggerer mutant mice. As reported earlier, RORα was required for regression of primitive dendrites before postnatal day 4 (P4). RORα was also necessary for PCs to form a single Purkinje layer from P0 to P4. The knock-down of RORα from P4 impaired the elimination of perisomatic dendrites and maturation of single stem dendrites in PCs at P8. Filopodia and spines were also absent in these PCs. The knock-down of RORα from P8 impaired the formation and maintenance of terminal dendritic branches of PCs at P14. Finally, even after dendrite formation was completed at P21, RORα was required for PCs to maintain dendritic complexity and functional synapses, but their mature innervation pattern by single climbing fibers was unaffected. Interestingly, overexpression of RORα in PCs at various developmental stages did not facilitate dendrite development, but had specific detrimental effects on PCs. Because RORα deficiency during development is closely related to the severity of spinocerebellar ataxia type 1, delineating the specific roles of RORα in PCs in vivo at different time windows during development and throughout adulthood would facilitate our understanding of the pathogenesis of cerebellar disorders. Significance statement: The genetic programs by which each neuron subtype develops and maintains dendritic arbors have remained largely unclear. This is partly because dendrite development is modulated dynamically by neuronal activities and interactions with local environmental cues in vivo. In addition, dendrites are formed and maintained by the

  19. Effects of inactivated porcine epidemic diarrhea virus on porcine monocyte-derived dendritic cells and intestinal dendritic cells.

    PubMed

    Gao, Qi; Zhao, Shanshan; Qin, Tao; Yin, Yinyan; Yu, Qinghua; Yang, Qian

    2016-06-01

    Porcine epidemic diarrhea (PED) is a serious infection in neonatal piglets. As the causative agent of PED, porcine epidemic diarrhea virus (PEDV) results in acute diarrhea and dehydration with high mortality rates in swine. Dendritic cells (DCs) are highly effective antigen-presenting cells to uptake and present viral antigens to T cells, which then initiate a distinct immune response. In this study, our results show that the expression of Mo-DCs surface markers such as SWC3a(+)CD1a(+), SWC3a(+)CD80/86(+) and SWC3a(+)SLA-II-DR(+) is increased after incubation with UV-PEDV for 24h. Mo-DCs incubated with UV-PEDV produce higher levels of IL-12 and INF-γ compared to mock-infected Mo-DCs. Interactions between Mo-DCs and UV-PEDV significantly stimulate T-cell proliferation in vitro. Consistent with these results, there is an enhancement in the ability of porcine intestinal DCs to activate T-cell proliferation in vivo. We conclude that UV-PEDV may be a useful and safe vaccine to trigger adaptive immunity.

  20. Spatial modelling of brief and long interactions between T cells and dendritic cells.

    PubMed

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2007-06-01

    In the early phases of an immune response, T cells of appropriate antigen specificity become activated by antigen-presenting cells in secondary lymphoid organs. Two-photon microscopy imaging experiments have shown that this stimulation occurs in distinct stages during which T cells exhibit different motilities and interactions with dendritic cells (DCs). In this paper, we utilize the Cellular Potts Model, a model formalism that takes cell shapes and cellular interactions explicitly into account, to simulate the dynamics of, and interactions between, T cells and DCs in the lymph node paracortex. Our three-dimensional simulations suggest that the initial decrease in T-cell motility after antigen appearance is due to "stop signals" transmitted by activated DCs to T cells. The long-lived interactions that occur at a later stage can only be explained by the presence of both stop signals and a high adhesion between specific T cells and antigen-bearing DCs. Furthermore, our results indicate that long-lasting contacts with T cells are promoted when DCs retract dendrites that detect a specific contact at lower velocities than other dendrites. Finally, by performing long simulations (after prior fitting to short time scale data) we are able to provide an estimate of the average contact duration between T cells and DCs.

  1. Identification of a unique B-cell-stimulating factor produced by a cloned dendritic cell.

    PubMed Central

    Clayberger, C; DeKruyff, R H; Fay, R; Cantor, H

    1985-01-01

    We describe a cloned dendritic cell, clone Den-1, which is a potent accessory cell for some B-cell responses. Clone Den-1 produces a unique lymphokine that induces polyclonal B-cell proliferation in the absence of other costimulators. This clone or factors produced by it also stimulate purified B cells to develop plaque-forming cell responses to type 2 antigens. The effect of this factor(s) on various B-cell populations and its relationship to previously described B-cell-stimulating factors is discussed. Images PMID:3871522

  2. Extracellular transport of cell-size particles and tumor cells by dendritic cells in culture.

    PubMed

    Thacker, Robert I; Retzinger, Andrew C; Cash, James G; Dentler, Michael D; Retzinger, Gregory S

    2013-12-01

    Many particulate materials of sizes approximating that of a cell disseminate after being introduced into the body. While some move about within phagocytic inflammatory cells, others appear to move about outside of, but in contact with, such cells. In this report, we provide unequivocal photomicroscopic evidence that cultured, mature, human dendritic cells can transport in extracellular fashion over significant distances both polymeric beads and tumor cells. At least in the case of polymeric beads, both fibrinogen and the β2-integrin subunit, CD18, appear to play important roles in the transport process. These discoveries may yield insight into a host of disease-related phenomena, including and especially tumor cell invasion and metastasis.

  3. Identification of novel dendritic cell subset markers in human blood.

    PubMed

    Schütz, Fabian; Hackstein, Holger

    2014-01-10

    Human dendritic cells (DC) are key regulators of innate and adaptive immunity that can be divided in at least three major subpopulations: plasmacytoid DC (pDC), myeloid type 1 DC (mDC1) and myeloid type 2 DC (mDC2) exhibiting different functions. However, research, diagnostic and cell therapeutic studies on human DC subsets are limited because only few DC subset markers have been identified so far. Especially mDC2 representing the rarest blood DC subset are difficult to be separated from mDC1 and pDC due to a paucity of mDC2 markers. We have combined multiparameter flow cytometry analysis of human blood DC subsets with systematic expression analysis of 332 surface antigens in magnetic bead-enriched blood DC samples. The initial analysis revealed eight novel putative DC subset markers CD26, CD85a, CD109, CD172a, CD200, CD200R, CD275 and CD301 that were subsequently tested in bulk peripheral blood mononuclear cell (PBMC) samples from healthy blood donors. Secondary analysis of PBMC samples confirmed three novel DC subset markers CD26 (dipeptidyl peptidase IV), CD85a (Leukocyte immunoglobulin-like receptor B3) and CD275 (inducible costimulator ligand). CD85a is specifically expressed in mDC1 and CD26 and CD275 represent novel mDC2 markers. These markers will facilitate human DC subset discrimination and additionally provide insight into potentially novel DC subset-specific functions.

  4. Adiponectin Receptor Signaling on Dendritic Cells Blunts Antitumor Immunity

    PubMed Central

    Tan, Peng H.; Tyrrell, Helen E.J.; Gao, Liquan; Xu, Danmei; Quan, Jianchao; Gill, Dipender; Rai, Lena; Ding, Yunchuan; Plant, Gareth; Chen, Yuan; Xue, John Z.; Handa, Ashok I.; Greenall, Michael J.; Walsh, Kenneth; Xue, Shao-An

    2015-01-01

    Immune escape is a fundamental trait of cancer. Dendritic cells (DC) that interact with T cells represent a crucial site for the development of tolerance to tumor antigens, but there remains incomplete knowledge about how DC-tolerizing signals evolve during tumorigenesis. In this study, we show that DCs isolated from patients with metastatic or locally advanced breast cancer express high levels of the adiponectin receptors AdipoR1 and AdipoR2, which are sufficient to blunt antitumor immunity. Mechanistic investigations of ligand–receptor interactions on DCs revealed novel signaling pathways for each receptor. AdipoR1 stimulated IL10 production by activating the AMPK and MAPKp38 pathways, whereas AdipoR2 modified inflammatory processes by activating the COX-2 and PPARγ pathways. Stimulation of these pathways was sufficient to block activation of NF-κB in DC, thereby attenuating their ability to stimulate antigen-specific T-cell responses. Together, our findings reveal novel insights into how DC-tolerizing signals evolve in cancer to promote immune escape. Furthermore, by defining a critical role for adiponectin signaling in this process, our work suggests new and broadly applicable strategies for immunometabolic therapy in patients with cancer. PMID:25261236

  5. Epigenetic program and transcription factor circuitry of dendritic cell development

    PubMed Central

    Lin, Qiong; Chauvistré, Heike; Costa, Ivan G.; Gusmao, Eduardo G.; Mitzka, Saskia; Hänzelmann, Sonja; Baying, Bianka; Klisch, Theresa; Moriggl, Richard; Hennuy, Benoit; Smeets, Hubert; Hoffmann, Kurt; Benes, Vladimir; Seré, Kristin; Zenke, Martin

    2015-01-01

    Dendritic cells (DC) are professional antigen presenting cells that develop from hematopoietic stem cells through successive steps of lineage commitment and differentiation. Multipotent progenitors (MPP) are committed to DC restricted common DC progenitors (CDP), which differentiate into specific DC subsets, classical DC (cDC) and plasmacytoid DC (pDC). To determine epigenetic states and regulatory circuitries during DC differentiation, we measured consecutive changes of genome-wide gene expression, histone modification and transcription factor occupancy during the sequel MPP-CDP-cDC/pDC. Specific histone marks in CDP reveal a DC-primed epigenetic signature, which is maintained and reinforced during DC differentiation. Epigenetic marks and transcription factor PU.1 occupancy increasingly coincide upon DC differentiation. By integrating PU.1 occupancy and gene expression we devised a transcription factor regulatory circuitry for DC commitment and subset specification. The circuitry provides the transcription factor hierarchy that drives the sequel MPP-CDP-cDC/pDC, including Irf4, Irf8, Tcf4, Spib and Stat factors. The circuitry also includes feedback loops inferred for individual or multiple factors, which stabilize distinct stages of DC development and DC subsets. In summary, here we describe the basic regulatory circuitry of transcription factors that drives DC development. PMID:26476451

  6. Cancer immunotherapy using dendritic cell-derived exosomes.

    PubMed

    Amigorena, S

    2000-01-01

    Dendritic cells (DCs) are the most potent antigen presenting cells and the only ones capable of inducing primary cytotoxic immune responses. We found that DCs secrete a population of membrane vesicles, called exosomes. Exosomes are 60-80 nm vesicles of endocytic origin. The protein composition of exosomes was subjected to a systematic proteomic analysis. Besides MHC and co-stimulatory molecules, exosomes bear several adhesion proteins, most likely involved in their specific subjected to targeting. We also found that exosomes accumulate several cytosolic factors, probably involved in their endosomal biogenesis. Like DCs, exosomes induced immune responses in vivo. Indeed, a single injection of DC-derived exosomes sensitized with tumor peptides induced potent anti tumor immune responses in mice and the eradication of established tumors. Tumor-specific cytotoxic T lymphocytes were found in the spleen of exosome-treated mice, and the anti tumor effect of exosomes was sensitive to in vivo depletion of CD8+ T cells. These results show that exosomes induce potent anti tumor effects in vivo, and strongly support the implementation of human DC-derived exosomes for cancer immunotherapy.

  7. Targeting dendritic cells for improved HIV-1 vaccines.

    PubMed

    Smed-Sörensen, Anna; Loré, Karin

    2013-01-01

    As dendritic cells (DCs) have the unique capacity to activate antigen-naive T cells they likely play a critical role in eliciting immune responses to vaccines. DCs are therefore being explored as attractive targets for vaccines, but understanding the interaction of DCs and clinically relevant vaccine antigens and adjuvants is a prerequisite. The HIV-1/AIDS epidemic continues to be a significant health problem, and despite intense research efforts over the past 30 years a protective vaccine has not yet been developed. A common challenge in vaccine design is to find a vaccine formulation that best shapes the immune response to protect against and/or control the given pathogen. Here, we discuss the importance of understanding the diversity, anatomical location and function of different human DC subsets in order to identify the optimal target cells for an HIV-1 vaccine. We review human DC interactions with some of the HIV-1 vaccine antigen delivery vehicles and adjuvants currently utilized in preclinical and clinical studies. Specifically, the effects of distinctly different vaccine adjuvants in terms of activation of DCs and improving DC function and vaccine efficacy are discussed. The susceptibility and responses of DCs to recombinant adenovirus vectors are reviewed, as well as the strategy of directly targeting DCs by using DC marker-specific monoclonal antibodies coupled to an antigen.

  8. Study of dendritic cell migration using micro-fabrication.

    PubMed

    Vargas, Pablo; Chabaud, Mélanie; Thiam, Hawa-Racine; Lankar, Danielle; Piel, Matthieu; Lennon-Dumenil, Ana-Maria

    2016-05-01

    Cell migration is a hallmark of dendritic cells (DCs) function. It is needed for DCs to scan their environment in search for antigens as well as to reach lymphatic organs in order to trigger T lymphocyte's activation. Such interaction leads to tolerance in the case of DCs migrating under homeostatic conditions or to immunity in the case of DCs migrating upon encounter with pathogen-associated molecular patterns. Cell migration is therefore essential for DCs to transfer information from peripheral tissues to lymphoid organs, thereby linking innate to adaptive immunity. This stresses the need to unravel the molecular mechanisms involved. However, the tremendous complexity of the tissue microenvironment as well as the limited spatio-temporal resolution of in vivo imaging techniques has made this task difficult. To bypass this problem, we have developed microfabrication-based experimental tools that are compatible with high-resolution imaging. Here, we will discuss how such devices can be used to study DC migration under controlled conditions that mimic their physiological environment in a robust quantitative manner.

  9. MicroRNAs affect dendritic cell function and phenotype

    PubMed Central

    Smyth, Lesley A; Boardman, Dominic A; Tung, Sim L; Lechler, Robert; Lombardi, Giovanna

    2015-01-01

    MicroRNA (miRNA) are small, non-coding RNA molecules that have been linked with immunity through regulating/modulating gene expression. A role for these molecules in T-cell and B-cell development and function has been well established. An increasing body of literature now highlights the importance of specific miRNA in dendritic cell (DC) development as well as their maturation process, antigen presentation capacity and cytokine release. Given the unique role of DC within the immune system, linking the innate and adaptive immune responses, understanding how specific miRNA affect DC function is of importance for understanding disease. In this review we summarize recent developments in miRNA and DC research, highlighting the requirement of miRNA in DC lineage commitment from bone marrow progenitors and for the development of subsets such as plasmacytoid DC and conventional DC. In addition, we discuss how infections and tumours modulate miRNA expression and consequently DC function. PMID:25244106

  10. GM-CSF alters dendritic cells in autoimmune diseases.

    PubMed

    Li, Bao-Zhu; Ye, Qian-Ling; Xu, Wang-Dong; Li, Jie-Hua; Ye, Dong-Qing; Xu, Yuekang

    2013-11-01

    Autoimmune diseases arise from an inappropriate immune response against self components, including macromolecules, cells, tissues, organs etc. They are often triggered or accompanied by inflammation, during which the levels of granulocyte macrophage colony-stimulating factor (GM-CSF) are elevated. GM-CSF is an inflammatory cytokine that has profound impact on the differentiation of immune system cells of myeloid lineage, especially dendritic cells (DCs) that play critical roles in immune initiation and tolerance, and is involved in the pathogenesis of autoimmune diseases. Although GM-CSF was discovered decades ago, recent studies with some new findings have shed an interesting light on the old hematopoietic growth factor. In the inflammatory autoimmune diseases, GM-CSF redirects the normal developmental pathway of DCs, conditions their antigen presentation capacities and endows them with unique cytokine signatures to affect autoimmune responses. Here we review the latest advances in the field, with the aim of demonstrating the effects of GM-CSF on DCs and their influences on autoimmune diseases. The summarized knowledge will help to design DC-based strategies for the treatment of autoimmune diseases.

  11. Dendritic branching angles of pyramidal cells across layers of the juvenile rat somatosensory cortex.

    PubMed

    Leguey, Ignacio; Bielza, Concha; Larrañaga, Pedro; Kastanauskaite, Asta; Rojo, Concepción; Benavides-Piccione, Ruth; DeFelipe, Javier

    2016-09-01

    The characterization of the structural design of cortical microcircuits is essential for understanding how they contribute to function in both health and disease. Since pyramidal neurons represent the most abundant neuronal type and their dendritic spines constitute the major postsynaptic elements of cortical excitatory synapses, our understanding of the synaptic organization of the neocortex largely depends on the available knowledge regarding the structure of pyramidal cells. Previous studies have identified several apparently common rules in dendritic geometry. We study the dendritic branching angles of pyramidal cells across layers to further shed light on the principles that determine the geometric shapes of these cells. We find that the dendritic branching angles of pyramidal cells from layers II-VI of the juvenile rat somatosensory cortex suggest common design principles, despite the particular morphological and functional features that are characteristic of pyramidal cells in each cortical layer. J. Comp. Neurol. 524:2567-2576, 2016. © 2016 Wiley Periodicals, Inc.

  12. Mannose receptor-mediated gene delivery into antigen presenting dendritic cells.

    PubMed

    Diebold, Sandra S; Plank, Christian; Cotten, Matt; Wagner, Ernst; Zenke, Martin

    2002-11-01

    Dendritic cells are professional antigen presenting cells and are unique in their ability to prime naïve T cells. Gene modification of dendritic cells is of particular interest for immunotherapy of diseases where the immune system has failed or is aberrantly regulated, such as in cancer or autoimmune disease, respectively. Dendritic cells abundantly express mannose receptor and mannose receptor-related receptors, and receptor-mediated gene transfer via mannose receptor offers a versatile tool for targeted gene delivery into these cells. Accordingly, mannose polyethylenimine DNA transfer complexes were generated and used for gene delivery into dendritic cells. Mannose receptor belongs to the group of scavenger receptors that allow dendritic cells to take up pathogenic material, which is directed for degradation and MHC class II presentation. Therefore, a limiting step of transgene expression by mannose receptor-mediated gene delivery is endosomal degradation of DNA. Several strategies have been explored to overcome this limitation including the addition of endosomolytic components to DNA transfer complexes like adenovirus particles and influenza peptides. Here, we review the current understanding of mannose receptor-mediated gene delivery into dendritic cells and discuss strategies to identify appropriate endosomolytic agents to improve DNA transfer efficacy.

  13. Glycyrrhiza uralensis water extract enhances dendritic cell maturation and antitumor efficacy of HPV dendritic cell-based vaccine

    PubMed Central

    Aipire, Adila; Li, Jinyu; Yuan, Pengfei; He, Jiang; Hu, Yelang; Liu, Lu; Feng, Xiaoli; Li, Yijie; Zhang, Fuchun; Yang, Jianhua; Li, Jinyao

    2017-01-01

    Licorice has been used as herbal medicine and natural sweetener. Here, we prepared Glycyrrhiza uralensis water extract (GUWE) and investigated the effect of GUWE on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We observed that GUWE dose-dependently promoted DC maturation and cytokine secretion through TLR4 signaling pathway. The capacity of DC to stimulate allogenic splenocyte proliferation was also enhanced by GUWE treatment. Compared with control group, GUWE treated DCs pulsed with human papillomavirus (HPV)-16 E6/E7 peptides significantly inhibited the tumor growth in both early and late therapeutic groups. In early therapeutic group, the frequencies of induced regulatory T cells (iTregs: CD4+CD25−Fopx3+) and CD4+ and CD8+ T cells were significantly decreased and increased, respectively. HPV-16-specific CD8+ T cell responses were significantly induced and negatively correlated with iTreg frequencies and tumor weight. These results indicated the immunoregulatory activities of licorice. PMID:28272545

  14. Glycyrrhiza uralensis water extract enhances dendritic cell maturation and antitumor efficacy of HPV dendritic cell-based vaccine.

    PubMed

    Aipire, Adila; Li, Jinyu; Yuan, Pengfei; He, Jiang; Hu, Yelang; Liu, Lu; Feng, Xiaoli; Li, Yijie; Zhang, Fuchun; Yang, Jianhua; Li, Jinyao

    2017-03-08

    Licorice has been used as herbal medicine and natural sweetener. Here, we prepared Glycyrrhiza uralensis water extract (GUWE) and investigated the effect of GUWE on the maturation and function of dendritic cells (DCs) and its adjuvant effect on DC-based vaccine. We observed that GUWE dose-dependently promoted DC maturation and cytokine secretion through TLR4 signaling pathway. The capacity of DC to stimulate allogenic splenocyte proliferation was also enhanced by GUWE treatment. Compared with control group, GUWE treated DCs pulsed with human papillomavirus (HPV)-16 E6/E7 peptides significantly inhibited the tumor growth in both early and late therapeutic groups. In early therapeutic group, the frequencies of induced regulatory T cells (iTregs: CD4(+)CD25(-)Fopx3(+)) and CD4(+) and CD8(+) T cells were significantly decreased and increased, respectively. HPV-16-specific CD8(+) T cell responses were significantly induced and negatively correlated with iTreg frequencies and tumor weight. These results indicated the immunoregulatory activities of licorice.

  15. Infection of Dendritic Cells by Lymphocytic Choriomeningitis Virus

    PubMed Central

    Sevilla, N.; Kunz, S.; McGavern, D.

    2017-01-01

    Dendritic cells (DCs) comprise the major antigen-presenting cells (APCs) of the host, uniquely programmed to stimulate immunologically naïve T lymphocytes. Viruses that can target and disorder the function of these cells enjoy a selective advantage. The cellular receptor for lymphocytic choriomeningitis virus (LCMV), Lassa fever virus (LFV), and several other arenaviruses is α-dystroglycan (α-DG). Among cells of the immune system, CD11c+ and DEC-205+ DCs primarily and preferentially express α-DG. By selection, strains and variants of LCMV generated as quasi-species that bind α-DG with high affinity replicate in the majority of CD11c+ and DEC-205+ (>75%) DCs, causing a generalized immunosuppression, and establish a persistent infection. In contrast, viral strains and variants that bind with low affinity to α-DG display minimal replication in CD11c+ and DEC-205+ DCs (<10%), rarely replicate in the white pulp, and generate a robust anti-LCMV CTL response that clears the virus infection. Hence, receptor-virus interaction on DCs in vivo is an essential step in the initiation of virus-induced immunosuppression and viral persistence. Investigation into the mechanism of how virus-infected DCs cause immunosuppression reveals loss of MHC class II surface expression and costimulatory molecules on surface of such DCs. As a consequence DCs are unable to act as APCs, initiate immune responses, and have a defect in migration into the T cell area. These data indicate that LCMV infection influences DC maturation and migration, leading to decreased T cell stimulatory capacity of DCs, events essential for the initiation of immune responses. Because several other viruses known to cause immunosuppression (HIV, measles) interact with DCs, the observations noted here are likely a common selective mechanism by which viruses also are able to evade the host s immune system. PMID:12797446

  16. Type I TARPs promote dendritic growth of early postnatal neocortical pyramidal cells in organotypic cultures.

    PubMed

    Hamad, Mohammad I K; Jack, Alexander; Klatt, Oliver; Lorkowski, Markus; Strasdeit, Tobias; Kott, Sabine; Sager, Charlotte; Hollmann, Michael; Wahle, Petra

    2014-04-01

    The ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazole propionate glutamate receptors (AMPARs) have been implicated in the establishment of dendritic architecture. The transmembrane AMPA receptor regulatory proteins (TARPs) regulate AMPAR function and trafficking into synaptic membranes. In the current study, we employ type I and type II TARPs to modulate expression levels and function of endogenous AMPARs and investigate in organotypic cultures (OTCs) of rat occipital cortex whether this influences neuronal differentiation. Our results show that in early development [5-10 days in vitro (DIV)] only the type I TARP γ-8 promotes pyramidal cell dendritic growth by increasing spontaneous calcium amplitude and GluA2/3 expression in soma and dendrites. Later in development (10-15 DIV), the type I TARPs γ-2, γ-3 and γ-8 promote dendritic growth, whereas γ-4 reduced dendritic growth. The type II TARPs failed to alter dendritic morphology. The TARP-induced dendritic growth was restricted to the apical dendrites of pyramidal cells and it did not affect interneurons. Moreover, we studied the effects of short hairpin RNA-induced knockdown of endogenous γ-8 and showed a reduction of dendritic complexity and amplitudes of spontaneous calcium transients. In addition, the cytoplasmic tail (CT) of γ-8 was required for dendritic growth. Single-cell calcium imaging showed that the γ-8 CT domain increases amplitude but not frequency of calcium transients, suggesting a regulatory mechanism involving the γ-8 CT domain in the postsynaptic compartment. Indeed, the effect of γ-8 overexpression was reversed by APV, indicating a contribution of NMDA receptors. Our results suggest that selected type I TARPs influence activity-dependent dendritogenesis of immature pyramidal neurons.

  17. Controlling T-Cell Activation with Synthetic Dendritic Cells Using the Multivalency Effect

    PubMed Central

    2017-01-01

    Artificial antigen-presenting cells (aAPCs) have recently gained a lot of attention. They efficiently activate T cells and serve as powerful replacements for dendritic cells in cancer immunotherapy. Focusing on a specific class of polymer-based aAPCs, so-called synthetic dendritic cells (sDCs), we have investigated the importance of multivalent binding on T-cell activation. Using antibody-functionalized sDCs, we have tested the influence of polymer length and antibody density. Increasing the multivalent character of the antibody-functionalized polymer lowered the effective concentration required for T-cell activation. This was evidenced for both early and late stages of activation. The most important effect observed was the significantly prolonged activation of the stimulated T cells, indicating that multivalent sDCs sustain T-cell signaling. Our results highlight the importance of multivalency for the design of aAPCs and will ultimately allow for better mimics of natural dendritic cells that can be used as vaccines in cancer treatment. PMID:28393131

  18. Dendrites of dentate gyrus granule cells contribute to pattern separation by controlling sparsity

    PubMed Central

    Chavlis, Spyridon; Petrantonakis, Panagiotis C.

    2016-01-01

    ABSTRACT The hippocampus plays a key role in pattern separation, the process of transforming similar incoming information to highly dissimilar, nonverlapping representations. Sparse firing granule cells (GCs) in the dentate gyrus (DG) have been proposed to undertake this computation, but little is known about which of their properties influence pattern separation. Dendritic atrophy has been reported in diseases associated with pattern separation deficits, suggesting a possible role for dendrites in this phenomenon. To investigate whether and how the dendrites of GCs contribute to pattern separation, we build a simplified, biologically relevant, computational model of the DG. Our model suggests that the presence of GC dendrites is associated with high pattern separation efficiency while their atrophy leads to increased excitability and performance impairments. These impairments can be rescued by restoring GC sparsity to control levels through various manipulations. We predict that dendrites contribute to pattern separation as a mechanism for controlling sparsity. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:27784124

  19. Dissecting thyroid hormone transport and metabolism in dendritic cells.

    PubMed

    Gigena, Nicolás; Alamino, Vanina A; Montesinos, María Del Mar; Nazar, Magalí; Louzada, Ruy A; Wajner, Simone M; Maia, Ana L; Masini-Repiso, Ana M; Carvalho, Denise P; Cremaschi, Graciela A; Pellizas, Claudia G

    2017-02-01

    We reported thyroid hormone (TH) receptor expression in murine dendritic cells (DCs) and 3,5,3'-triiodothyronine (T3)-dependent stimulation of DC maturation and ability to develop a Th1-type adaptive response. Moreover, an increased DC capacity to promote antigen-specific cytotoxic T-cell activity, exploited in a DC-based antitumor vaccination protocol, was revealed. However, putative effects of the main circulating TH, l-thyroxine (T4) and the mechanisms of TH transport and metabolism at DC level, crucial events for TH action at target cell level, were not known. Herein, we show that T4 did not reproduce those registered T3-dependent effects, finding that may reflect a homoeostatic control to prevent unspecific systemic activation of DCs. Besides, DCs express MCT10 and LAT2 TH transporters, and these cells mainly transport T3 with a favored involvement of MCT10 as its inhibition almost prevented T3 saturable uptake mechanism and reduced T3-induced IL-12 production. In turn, DCs express iodothyronine deiodonases type 2 and 3 (D2, D3) and exhibit both enzymatic activities with a prevalence towards TH inactivation. Moreover, T3 increased MCT10 and LAT2 expression and T3 efflux from DCs but not T3 uptake, whereas it induced a robust induction of D3 with a parallel slight reduction in D2. These findings disclose pivotal events involved in the mechanism of action of THs on DCs, providing valuable tools for manipulating the immunogenic potential of these cells. Furthermore, they broaden the knowledge of the TH mechanism of action at the immune system network.

  20. Dendritic cell based vaccines for HIV infection: the way ahead.

    PubMed

    García, Felipe; Plana, Montserrat; Climent, Nuria; León, Agathe; Gatell, Jose M; Gallart, Teresa

    2013-11-01

    Dendritic cells have a central role in HIV infection. On one hand, they are essential to induce strong HIV-specific CD4⁺ helper T-cell responses that are crucial to achieve a sustained and effective HIV-specific CD8⁺ cytotoxic T-lymphocyte able to control HIV replication. On the other hand, DCs contribute to virus dissemination and HIV itself could avoid a correct antigen presentation. As the efficacy of immune therapy and therapeutic vaccines against HIV infection has been modest in the best of cases, it has been hypothesized that ex vivo generated DC therapeutic vaccines aimed to induce effective specific HIV immune responses might overcome some of these problems. In fact, DC-based vaccine clinical trials have yielded the best results in this field. However, despite these encouraging results, functional cure has not been reached with this strategy in any patient. In this Commentary, we discuss new approaches to improve the efficacy and feasibility of this type of therapeutic vaccine.

  1. Dendritic Cells and Multiple Sclerosis: Disease, Tolerance and Therapy

    PubMed Central

    Mohammad, Mohammad G.; Hassanpour, Masoud; Tsai, Vicky W. W.; Li, Hui; Ruitenberg, Marc J.; Booth, David R.; Serrats, Jordi; Hart, Prue H.; Symonds, Geoffrey P.; Sawchenko, Paul E.; Breit, Samuel N.; Brown, David A.

    2013-01-01

    Multiple sclerosis (MS) is a devastating neurological disease that predominantly affects young adults resulting in severe personal and economic impact. The majority of therapies for this disease were developed in, or are beneficial in experimental autoimmune encephalomyelitis (EAE), the animal model of MS. While known to target adaptive anti-CNS immune responses, they also target, the innate immune arm. This mini-review focuses on the role of dendritic cells (DCs), the professional antigen presenting cells of the innate immune system. The evidence for a role for DCs in the appropriate regulation of anti-CNS autoimmune responses and their role in MS disease susceptibility and possible therapeutic utility are discussed. Additionally, the current controversy regarding the evidence for the presence of functional DCs in the normal CNS is reviewed. Furthermore, the role of CNS DCs and potential routes of their intercourse between the CNS and cervical lymph nodes are considered. Finally, the future role that this nexus between the CNS and the cervical lymph nodes might play in site directed molecular and cellular therapy for MS is outlined. PMID:23271370

  2. Impact of Aging on Dendritic Cell Functions in humans

    PubMed Central

    Agrawal, Anshu; Gupta, Sudhir

    2010-01-01

    Aging is a paradox of reduced immunity and chronic inflammation. Dendritic cells are central orchestrators of the immune response with a key role in the generation of immunity and maintenance of tolerance. The functions of DCs are compromised with age. There is no major effect on the numbers and phenotype of DC subsets in aged subjects; nevertheless, their capacity to phagocytose antigens and migrate is impaired with age. There is aberrant cytokine secretion by various DC subsets with CDCs secreting increased basal level of pro-inflammatory cytokines but the response on stimulation to foreign antigens is decreased. In contrast, the response to self antigens is increased suggesting erosion of peripheral self tolerance. PDC subset also secretes reduced IFN-alpha in response to viruses. The capacity of DCs to prime T cell responses is also affected. Aging thus has a profound affect on DC functions. Present review summarizes the effect of advancing age on DC functions in humans in the context of both immunity and tolerance. PMID:20619360

  3. Evidence of dysregulation of dendritic cells in primary HIV infection

    PubMed Central

    Sabado, Rachel Lubong; O'Brien, Meagan; Subedi, Abhignya; Qin, Li; Hu, Nan; Taylor, Elizabeth; Dibben, Oliver; Stacey, Andrea; Fellay, Jacques; Shianna, Kevin V.; Siegal, Frederick; Shodell, Michael; Shah, Kokila; Larsson, Marie; Lifson, Jeffrey; Nadas, Arthur; Marmor, Michael; Hutt, Richard; Margolis, David; Garmon, Donald; Markowitz, Martin; Valentine, Fred; Borrow, Persephone

    2010-01-01

    Myeloid and plasmacytoid dendritic cells (DCs) are important mediators of both innate and adaptive immunity against pathogens such as HIV. During the course of HIV infection, blood DC numbers fall substantially. In the present study, we sought to determine how early in HIV infection the reduction occurs and whether the remaining DC subsets maintain functional capacity. We find that both myeloid DC and plasmacytoid DC levels decline very early during acute HIV in-fection. Despite the initial reduction in numbers, those DCs that remain in circulation retain their function and are able to stimulate allogeneic T-cell responses, and up-regulate maturation markers plus produce cytokines/chemokines in response to stimulation with TLR7/8 agonists. Notably, DCs from HIV-infected subjects produced significantly higher levels of cytokines/chemokines in response to stimulation with TLR7/8 agonists than DCs from uninfected controls. Further examination of gene expression profiles indicated in vivo activation, either directly or indirectly, of DCs during HIV infection. Taken together, our data demonstrate that despite the reduction in circulating DC numbers, those that remain in the blood display hyperfunctionality and implicates a possible role for DCs in promoting chronic immune activation. PMID:20693428

  4. Evidence of dysregulation of dendritic cells in primary HIV infection.

    PubMed

    Sabado, Rachel Lubong; O'Brien, Meagan; Subedi, Abhignya; Qin, Li; Hu, Nan; Taylor, Elizabeth; Dibben, Oliver; Stacey, Andrea; Fellay, Jacques; Shianna, Kevin V; Siegal, Frederick; Shodell, Michael; Shah, Kokila; Larsson, Marie; Lifson, Jeffrey; Nadas, Arthur; Marmor, Michael; Hutt, Richard; Margolis, David; Garmon, Donald; Markowitz, Martin; Valentine, Fred; Borrow, Persephone; Bhardwaj, Nina

    2010-11-11

    Myeloid and plasmacytoid dendritic cells (DCs) are important mediators of both innate and adaptive immunity against pathogens such as HIV. During the course of HIV infection, blood DC numbers fall substantially. In the present study, we sought to determine how early in HIV infection the reduction occurs and whether the remaining DC subsets maintain functional capacity. We find that both myeloid DC and plasmacytoid DC levels decline very early during acute HIV infection. Despite the initial reduction in numbers, those DCs that remain in circulation retain their function and are able to stimulate allogeneic T-cell responses, and up-regulate maturation markers plus produce cytokines/chemokines in response to stimulation with TLR7/8 agonists. Notably, DCs from HIV-infected subjects produced significantly higher levels of cytokines/chemokines in response to stimulation with TLR7/8 agonists than DCs from uninfected controls. Further examination of gene expression profiles indicated in vivo activation, either directly or indirectly, of DCs during HIV infection. Taken together, our data demonstrate that despite the reduction in circulating DC numbers, those that remain in the blood display hyperfunctionality and implicates a possible role for DCs in promoting chronic immune activation.

  5. Dendritic cells and vaccine design for sexually-transmitted diseases.

    PubMed

    Duluc, Dorothee; Gannevat, Julien; Joo, Hyemee; Ni, Ling; Upchurch, Katherine; Boreham, Muriel; Carley, Michael; Stecher, Jack; Zurawski, Gerard; Oh, Sangkon

    2013-05-01

    Dendritic cells (DCs) are major antigen presenting cells (APCs) that can initiate and control host immune responses toward either immunity or tolerance. These features of DCs, as immune orchestrators, are well characterized by their tissue localizations as well as by their subset-dependent functional specialties and plasticity. Thus, the level of protective immunity to invading microbial pathogens can be dependent on the subsets of DCs taking up microbial antigens and their functional plasticity in response to microbial products, host cellular components and the cytokine milieu in the microenvironment. Vaccines are the most efficient and cost-effective preventive medicine against infectious diseases. However, major challenges still remain for the diseases caused by sexually-transmitted pathogens, including HIV, HPV, HSV and Chlamydia. We surmise that the establishment of protective immunity in the female genital mucosa, the major entry and transfer site of these pathogens, will bring significant benefit for the protection against sexually-transmitted diseases. Recent progresses made in DC biology suggest that vaccines designed to target proper DC subsets may permit us to establish protective immunity in the female genital mucosa against sexually-transmitted pathogens.

  6. 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.

  7. Trial watch: Dendritic cell-based anticancer therapy

    PubMed Central

    Bloy, Norma; Pol, Jonathan; Aranda, Fernando; Eggermont, Alexander; Cremer, Isabelle; Fridman, Wolf Hervé; Fučíková, Jitka; Galon, Jérôme; Tartour, Eric; Spisek, Radek; Dhodapkar, Madhav V.; Zitvogel, Laurence; Kroemer, Guido; Galluzzi, Lorenzo

    2014-01-01

    The use of patient-derived dendritic cells (DCs) as a means to elicit therapeutically relevant immune responses in cancer patients has been extensively investigated throughout the past decade. In this context, DCs are generally expanded, exposed to autologous tumor cell lysates or loaded with specific tumor-associated antigens (TAAs), and then reintroduced into patients, often in combination with one or more immunostimulatory agents. As an alternative, TAAs are targeted to DCs in vivo by means of monoclonal antibodies, carbohydrate moieties or viral vectors specific for DC receptors. All these approaches have been shown to (re)activate tumor-specific immune responses in mice, often mediating robust therapeutic effects. In 2010, the first DC-based preparation (sipuleucel-T, also known as Provenge®) has been approved by the US Food and Drug Administration (FDA) for use in humans. Reflecting the central position occupied by DCs in the regulation of immunological tolerance and adaptive immunity, the interest in harnessing them for the development of novel immunotherapeutic anticancer regimens remains high. Here, we summarize recent advances in the preclinical and clinical development of DC-based anticancer therapeutics. PMID:25941593

  8. Mannoproteins from Cryptococcus neoformans promote dendritic cell maturation and activation.

    PubMed

    Pietrella, Donatella; Corbucci, Cristina; Perito, Stefano; Bistoni, Giovanni; Vecchiarelli, Anna

    2005-02-01

    Our previous data show that mannoproteins (MPs) from Cryptococcus neoformans are able to induce protective responses against both C. neoformans and Candida albicans. Here we provide evidence that MPs foster maturation and activation of human dendritic cells (DCs). Maturation was evaluated by the ability of MPs to facilitate expression of costimulatory molecules such as CD40, CD86, CD83, and major histocompatibility complex classes I and II and to inhibit receptors such as CD14, CD16, and CD32. Activation of DCs was measured by the capacity of MPs to promote interleukin-12 and tumor necrosis factor alpha secretion. DC-induced maturation and interleukin-12 induction are largely mediated by engagement of mannose receptors and presume MP internalization and degradation. DC activation leads to IkappaBalpha phosphorylation, which is necessary for nuclear factor kappaB transmigration into the nucleus. MP-loaded DCs are efficient stimulators of T cells and show a remarkable capacity to promote CD4 and CD8 proliferation. In conclusion, we have evidenced a novel regulatory role of MPs that promotes their candidacy as a vaccine against fungi.

  9. Mannoproteins from Cryptococcus neoformans Promote Dendritic Cell Maturation and Activation

    PubMed Central

    Pietrella, Donatella; Corbucci, Cristina; Perito, Stefano; Bistoni, Giovanni; Vecchiarelli, Anna

    2005-01-01

    Our previous data show that mannoproteins (MPs) from Cryptococcus neoformans are able to induce protective responses against both C. neoformans and Candida albicans. Here we provide evidence that MPs foster maturation and activation of human dendritic cells (DCs). Maturation was evaluated by the ability of MPs to facilitate expression of costimulatory molecules such as CD40, CD86, CD83, and major histocompatibility complex classes I and II and to inhibit receptors such as CD14, CD16, and CD32. Activation of DCs was measured by the capacity of MPs to promote interleukin-12 and tumor necrosis factor alpha secretion. DC-induced maturation and interleukin-12 induction are largely mediated by engagement of mannose receptors and presume MP internalization and degradation. DC activation leads to IκBα phosphorylation, which is necessary for nuclear factor κB transmigration into the nucleus. MP-loaded DCs are efficient stimulators of T cells and show a remarkable capacity to promote CD4 and CD8 proliferation. In conclusion, we have evidenced a novel regulatory role of MPs that promotes their candidacy as a vaccine against fungi. PMID:15664921

  10. Water-soluble and fluorescent dendritic perylene bisimides for live-cell imaging.

    PubMed

    Gao, Baoxiang; Li, Hongxia; Liu, Hongmei; Zhang, Licui; Bai, Qianqian; Ba, Xinwu

    2011-04-07

    We prepared dendritic perylene bisimide probes with triblock structures: perylene bisimides fluorescence cores, branched oligo(glutamic acid)s and polyethylene glycol chains. These probes showed good water solubility, low cytotoxicity and strong fluorescence in live cells.

  11. Mature dendritic cell derived from cryopreserved immature dendritic cell shows impaired homing ability and reduced anti-viral therapeutic effects

    PubMed Central

    Zhou, Qianqian; Zhang, Yulong; Zhao, Man; Wang, Xiaohui; Ma, Cong; Jiang, Xinquan; Wu, Tao; Wang, Donggen; Zhan, Linsheng

    2016-01-01

    Cryopreservation is critical in reducing redundant operations and also in quality control in dendritic cell (DC) therapy. Full maturation and efficient homing of DCs to T cell-region constitute a crucial aspect of DC immunotherapy; however, the in vivo migration and distribution pattern, as well as the anti-viral effect of DCs that matured from cryopreserved immature DCs (cryoim-mDCs) remain to be revealed. In the present study, we compared cryoim-mDCs with DCs matured from fresh immature DCs (fmDCs) in the aspects of phenotypes, in vivo homing capacities as well as the anti-viral therapeutic effects to further clarify the effect of cryopreservation on DC-based cytotherapy. The results showed that cryopreservation impaired the homing ability of DCs which was associated with the reduced expression of CCR7 and disturbed cytoskeleton arrangement. Moreover, the antigen-specific CD8+ T cell response induced by cryoim-mDCs was much weaker than that induced by fmDCs in both the spleen and liver draining lymph nodes, which provided reduced protection from viral invasions. In conclusion, cryopreservation is a good method to keep the viability of immature DCs, however, the in vivo homing capacity and anti-viral therapeutic effect of DCs matured from frozen immature DCs were hindered to some extent. PMID:27958383

  12. Intracellular polysilicon barcodes for cell tracking.

    PubMed

    Fernandez-Rosas, Elisabet; Gómez, Rodrigo; Ibañez, Elena; Barrios, Leonardo; Duch, Marta; Esteve, Jaume; Nogués, Carme; Plaza, José Antonio

    2009-11-01

    During the past decade, diverse types of barcode have been designed in order to track living cells in vivo or in vitro, but none of them offer the possibility to follow an individual cell up to ten or more days. Using silicon microtechnologies a barcode sufficiently small to be introduced into a cell, yet visible and readily identifiable under an optical microscope, is designed. Cultured human macrophages are able to engulf the barcodes due to their phagocytic ability and their viability is not affected. The utility of the barcodes for cell tracking is demonstrated by following individual cells for up to ten days in culture and recording their locomotion. Interestingly, silicon microtechnology allows the mass production of reproducible codes at low cost with small features (bits) in the micrometer range that are additionally biocompatible.

  13. 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

  14. Dendritic cell potentials of early lymphoid and myeloid progenitors.

    PubMed

    Manz, M G; Traver, D; Miyamoto, T; Weissman, I L; Akashi, K

    2001-06-01

    It has been proposed that there are at least 2 classes of dendritic cells (DCs), CD8alpha(+) DCs derived from the lymphoid lineage and CD8alpha(-) DCs derived from the myeloid lineage. Here, the abilities of lymphoid- and myeloid-restricted progenitors to generate DCs are compared, and their overall contributions to the DC compartment are evaluated. It has previously been shown that primitive myeloid-committed progenitors (common myeloid progenitors [CMPs]) are efficient precursors of both CD8alpha(+) and CD8alpha(-) DCs in vivo. Here it is shown that the earliest lymphoid-committed progenitors (common lymphoid progenitors [CLPs]) and CMPs and their progeny granulocyte-macrophage progenitors (GMPs) can give rise to functional DCs in vitro and in vivo. CLPs are more efficient in generating DCs than their T-lineage descendants, the early thymocyte progenitors and pro-T cells, and CMPs are more efficient DC precursors than the descendant GMPs, whereas pro-B cells and megakaryocyte-erythrocyte progenitors are incapable of generating DCs. Thus, DC developmental potential is preserved during T- but not B-lymphoid differentiation from CLP and during granulocyte-macrophage but not megakaryocyte-erythrocyte development from CMP. In vivo reconstitution experiments show that CLPs and CMPs can reconstitute CD8alpha(+) and CD8alpha(-) DCs with similar efficiency on a per cell basis. However, CMPs are 10-fold more numerous than CLPs, suggesting that at steady state, CLPs provide only a minority of splenic DCs and approximately half the DCs in thymus, whereas most DCs, including CD8alpha(+) and CD8alpha(-) subtypes, are of myeloid origin. (Blood. 2001;97:3333-3341)

  15. 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.

  16. Simple chemicals can induce maturation and apoptosis of dendritic cells

    PubMed Central

    Manome, H; Aiba, S; Tagami, H

    1999-01-01

    As is well known in the case of Langerhans cells, dendritic cells (DCs) play a crucial role in the initiation of immunity to simple chemicals such as noted in the contact hypersensitivity. Because DCs are scattered in non‐lymphoid organs as immature cells, they must be activated to initiate primary antigen‐specific immune reactions. Therefore, we hypothesized that some simple chemicals must affect the function of DCs. In this paper, we first demonstrated that human monocyte‐derived DCs responded to such simple chemicals as 2,4‐dinitrochlorobenzene (DNCB), 2,4,6‐trinitrochlorobenzene (TNCB), 2,4‐dinitrofluorobenzene (DNFB), NiCl2, MnCl2, CoCl2, SnCl2, and CdSO4 by augmenting their expression of CD86 or human leucocyte antigen‐DR (HLA‐DR), down‐regulating c‐Fms expression or increasing their production of tumour necrosis factor‐α (TNF‐α). In addition, the DCs stimulated with the chemicals demonstrated increased allogeneic T‐cell stimulatory function. Next, we found that, among these chemicals, only NiCl2 and CoCl2 induced apoptosis in them. Finally, we examined the effects of these chemicals on CD86 expression by three different macrophage subsets and DCs induced from the cultures of human peripheral blood monocytes in the presence of macrophage colony‐stimulating factor (M‐CSF), M‐CSF + interleukin‐4 (IL‐4), granulocyte–macrophage colony‐stimulating factor (GM‐CSF), and GM‐CSF + IL‐4, respectively. Among them, only DCs dramatically augmented their expression of CD86. These observations have revealed unique characteristics of DCs, which convert chemical stimuli to augmentation of their antigen presenting function, although their responses to different chemicals were not necessarily uniform in the phenotypic changes, cytokine production or in the induction of apoptosis. PMID:10594678

  17. 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

  18. Melanoma cell-derived exosomes alter macrophage and dendritic cell functions in vitro.

    PubMed

    Marton, Annamaria; Vizler, Csaba; Kusz, Erzsebet; Temesfoi, Viktoria; Szathmary, Zsuzsa; Nagy, Krisztina; Szegletes, Zsolt; Varo, Gyorgy; Siklos, Laszlo; Katona, Robert L; Tubak, Vilmos; Howard, O M Zack; Duda, Erno; Minarovits, Janos; Nagy, Katalin; Buzas, Krisztina

    2012-01-01

    To clarify controversies in the literature of the field, we have purified and characterized B16F1 melanoma cell derived exosomes (mcd-exosomes) then we attempted to dissect their immunological activities. We tested how mcd-exosomes influence CD4+ T cell proliferation induced by bone marrow derived dendritic cells; we quantified NF-κB activation in mature macrophages stimulated with mcd-exosomes, and we compared the cytokine profile of LPS-stimulated, IL-4 induced, and mcd-exosome treated macrophages. We observed that mcd-exosomes helped the maturation of dendritic cells, enhancing T cell proliferation induced by the treated dendritic cells. The exosomes also activated macrophages, as measured by NF-κB activation. The cytokine and chemokine profile of macrophages treated with tumor cell derived exosomes showed marked differences from those induced by either LPS or IL-4, and it suggested that exosomes may play a role in the tumor progression and metastasis formation through supporting tumor immune escape mechanisms.

  19. 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.

  20. Simulated Responses of Cerebellar Purkinje Cells are Independent of the Dendritic Location of Granule Cell Synaptic Inputs

    NASA Astrophysics Data System (ADS)

    de Schutter, Erik; Bower, James M.

    1994-05-01

    Cerebellar Purkinje cell responses to granule cell synaptic inputs were examined with a computer model including active dendritic conductances. Dendritic P-type Ca2+ channels amplified postsynaptic responses when the model was firing at a physiological rate. Small synchronous excitatory inputs applied distally on the large dendritic tree resulted in somatic responses of similar size to those generated by more proximal inputs. In contrast, in a passive model the somatic postsynaptic potentials to distal inputs were 76% smaller. The model predicts that the somatic firing response of Purkinje cells is relatively insensitive to the exact dendritic location of synaptic inputs. We describe a mechanism of Ca2+-mediated synaptic amplification, based on the subspiking threshold recruitment of P-type Ca2+ channels in the dendritic branches surrounding the input site.

  1. The microRNA bantam regulates a developmental transition in epithelial cells that restricts sensory dendrite growth.

    PubMed

    Jiang, Nan; Soba, Peter; Parker, Edward; Kim, Charles C; Parrish, Jay Z

    2014-07-01

    As animals grow, many early born structures grow by cell expansion rather than cell addition; thus growth of distinct structures must be coordinated to maintain proportionality. This phenomenon is particularly widespread in the nervous system, with dendrite arbors of many neurons expanding in concert with their substrate to sustain connectivity and maintain receptive field coverage as animals grow. After rapidly growing to establish body wall coverage, dendrites of Drosophila class IV dendrite arborization (C4da) neurons grow synchronously with their substrate, the body wall epithelium, providing a system to study how proportionality is maintained during animal growth. Here, we show that the microRNA bantam (ban) ensures coordinated growth of C4da dendrites and the epithelium through regulation of epithelial endoreplication, a modified cell cycle that entails genome amplification without cell division. In Drosophila larvae, epithelial endoreplication leads to progressive changes in dendrite-extracellular matrix (ECM) and dendrite-epithelium contacts, coupling dendrite/substrate expansion and restricting dendrite growth beyond established boundaries. Moreover, changes in epithelial expression of cell adhesion molecules, including the beta-integrin myospheroid (mys), accompany this developmental transition. Finally, endoreplication and the accompanying changes in epithelial mys expression are required to constrain late-stage dendrite growth and structural plasticity. Hence, modulating epithelium-ECM attachment probably influences substrate permissivity for dendrite growth and contributes to the dendrite-substrate coupling that ensures proportional expansion of the two cell types.

  2. Endogenous Galectin-3 Is Localized in Membrane Lipid Rafts and Regulates Migration of Dendritic Cells

    PubMed Central

    Hsu, Daniel K.; Chernyavsky, Alexander I.; Chen, Huan-Yuan; Yu, Lan; Grando, Sergei A.; Liu, Fu-Tong

    2008-01-01

    This study reveals a function of endogenous galectin-3, an animal lectin recognizing β-galactosides, in regulating dendritic cell motility both in vitroand in vivo,which to our knowledge is unreported. First, galectin-3-deficient (gal3−/−) bone marrow-derived dendritic cells exhibited defective chemotaxis compared to gal3+/+ cells. Second, cutaneous dendritic cells in gal3−/− mice displayed reduced migration to draining lymph nodes upon hapten stimulation compared to gal3+/+ mice. Moreover, gal3−/− mice were impaired in the development of contact hypersensitivity relative to gal3+/+ mice in response to a hapten, a process in which dendritic cell trafficking to lymph nodes is critical. In addition, defective signaling was detected in gal3−/− cells upon chemokine receptor activation. By immunofluorescence microscopy, we observed that galectin-3 is localized in membrane ruffles and lamellipodia in stimulated dendritic cells and macrophages. Furthermore, galectin-3 was enriched in lipid raft domains under these conditions. Finally, we determined that ruffles on gal3−/− cells contained structures with lower complexity compared to gal3+/+ cells. In view of the participation of membrane ruffles in signal transduction and cell motility, we conclude that galectin-3 regulates cell migration by functioning at these structures. PMID:18843294

  3. 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.

  4. Modulation of respiratory dendritic cells during Klebsiella pneumonia infection

    PubMed Central

    2013-01-01

    Background Klebsiella pneumoniae is a leading cause of severe hospital-acquired respiratory tract infections and death but little is known regarding the modulation of respiratory dendritic cell (DC) subsets. Plasmacytoid DC (pDC) are specialized type 1 interferon producing cells and considered to be classical mediators of antiviral immunity. Method By using multiparameter flow cytometry analysis we have analysed the modulation of respiratory DC subsets after intratracheal Klebsiella pneumonia infection. Results Data indicate that pDCs and MoDC were markedly elevated in the post acute pneumonia phase when compared to mock-infected controls. Analysis of draining mediastinal lymph nodes revealed a rapid increase of activated CD103+ DC, CD11b+ DC and MoDC within 48 h post infection. Lung pDC identification during bacterial pneumonia was confirmed by extended phenotyping for 120G8, mPDCA-1 and Siglec-H expression and by demonstration of high Interferon-alpha producing capacity after cell sorting. Cytokine expression analysis of ex vivo-sorted respiratory DC subpopulations from infected animals revealed elevated Interferon-alpha in pDC, elevated IFN-gamma, IL-4 and IL-13 in CD103+ DC and IL-19 and IL-12p35 in CD11b+ DC subsets in comparison to CD11c+ MHC-class IIlow cells indicating distinct functional roles. Antigen-specific naive CD4+ T cell stimulatory capacity of purified respiratory DC subsets was analysed in a model system with purified ovalbumin T cell receptor transgenic naive CD4+ responder T cells and respiratory DC subsets, pulsed with ovalbumin and matured with Klebsiella pneumoniae lysate. CD103+ DC and CD11b+ DC subsets represented the most potent naive CD4+ T helper cell activators. Conclusion These results provide novel insight into the activation of respiratory DC subsets during Klebsiella pneumonia infection. The detection of increased respiratory pDC numbers in bacterial pneumonia may indicate possible novel pDC functions with respect to lung repair

  5. Cryptococcus gattii is killed by dendritic cells, but evades adaptive immunity by failing to induce dendritic cell maturation.

    PubMed

    Huston, Shaunna M; Li, Shu Shun; Stack, Danuta; Timm-McCann, Martina; Jones, Gareth J; Islam, Anowara; Berenger, Byron M; Xiang, Richard F; Colarusso, Pina; Mody, Christopher H

    2013-07-01

    During adaptive immunity to pathogens, dendritic cells (DCs) capture, kill, process, and present microbial Ags to T cells. Ag presentation is accompanied by DC maturation driven by appropriate costimulatory signals. However, current understanding of the intricate regulation of these processes remains limited. Cryptococcus gattii, an emerging fungal pathogen in the Pacific Northwest of Canada and the United States, fails to stimulate an effective immune response in otherwise healthy hosts leading to morbidity or death. Because immunity to fungal pathogens requires intact cell-mediated immunity initiated by DCs, we asked whether C. gattii causes dysregulation of DC functions. C. gattii was efficiently bound and internalized by human monocyte-derived DCs, trafficked to late phagolysosomes, and killed. Yet, even with this degree of DC activation, the organism evaded pathways leading to DC maturation. Despite the ability to recognize and kill C. gattii, immature DCs failed to mature; there was no increased expression of MHC class II, CD86, CD83, CD80, and CCR7, or decrease of CD11c and CD32, which resulted in suboptimal T cell responses. Remarkably, no increase in TNF-α was observed in the presence of C. gattii. However, addition of recombinant TNF-α or stimulation that led to TNF-α production restored DC maturation and restored T cell responses. Thus, despite early killing, C. gattii evades DC maturation, providing a potential explanation for its ability to infect immunocompetent individuals. We have also established that DCs retain the ability to recognize and kill C. gattii without triggering TNF-α, suggesting independent or divergent activation pathways among essential DC functions.

  6. Transcriptional and functional characterization of CD137L-dendritic cells identifies a novel dendritic cell phenotype

    PubMed Central

    Harfuddin, Zulkarnain; Dharmadhikari, Bhushan; Wong, Siew Cheng; Duan, Kaibo; Poidinger, Michael; Kwajah, Shaqireen; Schwarz, Herbert

    2016-01-01

    The importance of monocyte-derived dendritic cells (DCs) is evidenced by the fact that they are essential for the elimination of pathogens. Although in vitro DCs can be generated by treatment of monocytes with GM-CSF and IL-4, it is unknown what stimuli induce differentiation of DCs in vivo. CD137L-DCs are human monocyte-derived DC that are generated by CD137 ligand (CD137L) signaling. We demonstrate that the gene signature of in vitro generated CD137L-DCs is most similar to those of GM-CSF and IL-4-generated immature DCs and of macrophages. This is reminiscent of in vivo inflammatory DC which also have been reported to share gene signatures with monocyte-derived DCs and macrophages. Performing direct comparison of deposited human gene expression data with a CD137L-DC dataset revealed a significant enrichment of CD137L-DC signature genes in inflammatory in vivo DCs. In addition, surface marker expression and cytokine secretion by CD137L-DCs resemble closely those of inflammatory DCs. Further, CD137L-DCs express high levels of adhesion molecules, display strong attachment, and employ the adhesion molecule ALCAM to stimulate T cell proliferation. This study characterizes the gene expression profile of CD137L-DCs, and identifies significant similarities of CD137L-DCs with in vivo inflammatory monocyte-derived DCs and macrophages. PMID:27431276

  7. [Establishment of induced pluripotent stem cells from adipose tissue-derived stem cells for dendritic cell-based cancer vaccines].

    PubMed

    Matsushita, Norimasa; Kobayashi, Hajime; Aruga, Atsushi; Yamamoto, Masakazu

    2014-04-01

    Recently, studies on regenerative stem cell therapy are being encouraged, and efforts to generate dendritic cells, which play important roles in cancer immunotherapy, from stem cells are being made in the field of tumor immunology. Therapeutic acquisition of stem cells has important clinical applications. Studies on induced pluripotent stem(iPS)cells generated from somatic cells with pluripotent genes have advanced in recent years. Stem cells are reported to be found in adipose tissue (adipose-derived stem cells, ADSC). Our goal is to develop a new cancer vaccine by using dendritic cells generated from ADSC. In a preliminary study, we examined whether iPS cells can be generated from ADSC to serve as a source of dendritic cells.We introduced a plasmid with pluripotent genes(OCT3/4, KLF4, SOX2, L-MYC, LIN28, p53-shRNA)into an ADSC strain derived from adipose tissue by electroporation and subsequently cultured the cells for further examination. A colony sugges- tive of iPS cells from ADSC was observed. OCT3/4, KLF4, SOX2, L-MYC, and LIN28 mRNAs were expressed in the cultured cells, as confirmed by reverse transcriptase-polymerase chain reaction(RT-PCR). On the basis of these results, we confirmed that iPS cells were generated from ADSC. The method of inducing dendritic cells from iPS cells has already been reported, and the results of this study suggest that ADSC is a potential source of dendritic cells.

  8. Regulation of Dendritic Cell Function by Dietary Polyphenols.

    PubMed

    del Cornò, Manuela; Scazzocchio, Beatrice; Masella, Roberta; Gessani, Sandra

    2016-01-01

    Marked changes in socioeconomic status, cultural traditions, population growth, and agriculture have been affecting diets worldwide. Nutrition is known to play a pivotal role in the pathogenesis of several chronic diseases, and the use of bioactive food compounds at pharmacologic doses is emerging as a preventive and/or therapeutic approach to target metabolic dysregulations occurring in aging, obesity-related chronic diseases, and cancer. Only recently have data on the effects of specific nutrients or food on the immune system become available, and studies regarding the human immune system are still in their infancy. Beyond providing essential nutrients, diet can actively influence the immune system. Understanding how diet and nutritional status influence the innate and adaptive arms of our immune system represents an area of scientific need, opportunity, and challenge. The insights gleaned should help to address several pressing global health problems. Recently, biologically active polyphenols, which are widespread constituents of fruit and vegetables, have gained importance as complex regulators of various cellular processes, critically involved in the maintenance of body homeostasis. This review outlines the potential effects of polyphenols on the function of dendritic cells (DCs), key players in the orchestration of the immune response. Their effects on different aspects of DC biology including differentiation, maturation, and DC capacity to shift immune response toward tolerance or immune activation will be outlined.

  9. Phenotypic Characterization of Five Dendritic Cell Subsets in Human Tonsils

    PubMed Central

    Summers, Kelly L.; Hock, Barry D.; McKenzie, Judith L.; Hart, Derek N. J.

    2001-01-01

    Heterogeneous expression of several antigens on the three currently defined tonsil dendritic cell (DC) subsets encouraged us to re-examine tonsil DCs using a new method that minimized DC differentiation and activation during their preparation. Three-color flow cytometry and dual-color immunohistology was used in conjunction with an extensive panel of antibodies to relevant DC-related antigens to analyze lin− HLA-DR+ tonsil DCs. Here we identify, quantify, and locate five tonsil DC subsets based on their relative expression of the HLA-DR, CD11c, CD13, and CD123 antigens. In situ localization identified four of these DC subsets as distinct interdigitating DC populations. These included three new interdigitating DC subsets defined as HLA-DRhi CD11c+ DCs, HLA-DRmod CD11c+ CD13+ DCs, and HLA-DRmod CD11c− CD123− DCs, as well as the plasmacytoid DCs (HLA-DRmod CD11c− CD123+). These subsets differed in their expression of DC-associated differentiation/activation antigens and co-stimulator molecules including CD83, CMRF-44, CMRF-56, 2-7, CD86, and 4-1BB ligand. The fifth HLA-DRmod CD11c+ DC subset was identified as germinal center DCs, but contrary to previous reports they are redefined as lacking the CD13 antigen. The definition and extensive phenotypic analysis of these five DC subsets in human tonsil extends our understanding of the complexity of DC biology. PMID:11438475

  10. The Influence of Ouabain on Human Dendritic Cells Maturation

    PubMed Central

    Nascimento, C. R.; Valente, R. C.; Echevarria-Lima, J.; Fontes, C. F. L.; de Araujo-Martins, L.; Araujo, E. G.; Rumjanek, V. M.

    2014-01-01

    Although known as a Na,K-ATPase inhibitor, several other cellular and systemic actions have been ascribed to the steroid Ouabain (Oua). Particularly in the immune system, our group showed that Ouabain acts on decreasing lymphocyte proliferation, synergizing with glucocorticoids in spontaneous thymocyte apoptosis, and also lessening CD14 expression and blocking CD16 upregulation on human monocytes. However, Ouabain effects on dendritic cells (DCs) were not explored so far. Considering the peculiar plasticity and the importance of DCs in immune responses, the aim of our study was to investigate DC maturation under Ouabain influence. To generate immature DCs, human monocytes were cultured with IL-4 and GM-CSF (5 days). To investigate Ouabain role on DC activation, DCs were stimulated with TNF-α for 48 h in the presence or absence of Ouabain. TNF-induced CD83 expression and IL-12 production were abolished in DCs incubated with 100 nM Ouabain, though DC functional capacity concerning lymphocyte activation remained unaltered. Nevertheless, TNF-α-induced antigen capture downregulation, another maturation marker, occurred even in the presence of Ouabain. Besides, Ouabain increased HLA-DR and CD86 expression, whereas CD80 expression was maintained. Collectively, our results suggest that DCs respond to Ouabain maturating into a distinct category, possibly contributing to the balance between immunity and tolerance. PMID:25609892

  11. Adipose Recruitment and Activation of Plasmacytoid Dendritic Cells Fuel Metaflammation.

    PubMed

    Ghosh, Amrit Raj; Bhattacharya, Roopkatha; Bhattacharya, Shamik; Nargis, Titli; Rahaman, Oindrila; Duttagupta, Pritam; Raychaudhuri, Deblina; Liu, Chinky Shiu Chen; Roy, Shounak; Ghosh, Parasar; Khanna, Shashi; Chaudhuri, Tamonas; Tantia, Om; Haak, Stefan; Bandyopadhyay, Santu; Mukhopadhyay, Satinath; Chakrabarti, Partha; Ganguly, Dipyaman

    2016-11-01

    In obese individuals, visceral adipose tissue (VAT) is the seat of chronic low-grade inflammation (metaflammation), but the mechanistic link between increased adiposity and metaflammation largely remains unclear. In obese individuals, deregulation of a specific adipokine, chemerin, contributes to innate initiation of metaflammation by recruiting circulating plasmacytoid dendritic cells (pDCs) into VAT through chemokine-like receptor 1 (CMKLR1). Adipose tissue-derived high-mobility group B1 (HMGB1) protein activates Toll-like receptor 9 (TLR9) in the adipose-recruited pDCs by transporting extracellular DNA through receptor for advanced glycation end products (RAGE) and induces production of type I interferons (IFNs). Type I IFNs in turn help in proinflammatory polarization of adipose-resident macrophages. IFN signature gene expression in VAT correlates with both adipose tissue and systemic insulin resistance (IR) in obese individuals, which is represented by ADIPO-IR and HOMA2-IR, respectively, and defines two subgroups with different susceptibility to IR. Thus, this study reveals a pathway that drives adipose tissue inflammation and consequent IR in obesity.

  12. An Engineered Herpesvirus Activates Dendritic Cells and Induces Protective Immunity

    PubMed Central

    Ma, Yijie; Chen, Min; Jin, Huali; Prabhakar, Bellur S.; Valyi-Nagy, Tibor; He, Bin

    2017-01-01

    Herpes simplex viruses (HSV) are human pathogens that switch between lytic and latent infection. While attenuated HSV is explored for vaccine, the underlying event remains poorly defined. Here we report that recombinant HSV-1 with a mutation in the γ134.5 protein, a virulence factor, stimulates dendritic cell (DC) maturation which is dependent on TANK-binding kinase 1 (TBK1). When exposed to CD11+ DCs, the mutant virus that lacks the amino terminus of γ134.5 undergoes temporal replication without production of infectious virus. Mechanistically, this leads to sequential phosphorylation of interferon regulatory factor 3 (IRF3) and p65/RelA. In correlation, DCs up-regulate the expression of co-stimulatory molecules and cytokines. However, selective inhibition of TBK1 precludes phosphorylation of IRF3 and subsequent DC activation by the γ134.5 mutant. Herein, the γ134.5 mutant is immune-stimulatory and non-destructive to DCs. Remarkably, upon immunization the γ134.5 mutant induces protection against lethal challenge by the wild type virus, indicative of its vaccine potential. Furthermore, CD11+ DCs primed by the γ134.5 mutant in vivo mediate protection upon adoptive transfer. These results suggest that activation of TBK1 by engineered HSV is crucial for DC maturation, which may contribute to protective immunity. PMID:28150813

  13. Exopolysaccharide from Trichoderma pseudokoningii promotes maturation of murine dendritic cells.

    PubMed

    Xu, Yanghui; Li, Jing; Ju, Jing; Shen, Bingxiang; Chen, Guochuang; Qian, Wen; Zhu, Lei; Lu, Jingbo; Liu, Chunyan; Qin, Guozheng; Wang, Guodong; Chen, Kaoshan

    2016-11-01

    Dendritic cells (DCs) are the key regulators of immune responses. In this study, the effect of an exopolysaccharide (EPS) from the culture broth of Trichoderma pseudokoningii on the phenotypic and functional maturation of murine DCs and its underlying molecular mechanisms were investigated. It showed that EPS induced the morphological changes of DCs and the enhanced expression of DCs featured surface molecules CD11c, CD86, CD80 and major histocompatibility complex II (MHC-II). Flow cytometry analysis showed that the treatment with EPS could reduce FITC-dextran uptake by DCs. Sequentially, the results of ELISA indicated that EPS could increase the production of interleukin-12p70 (IL-12p70) in culture supernatant of DCs. Immunofluorescence staining and western blot analysis further revealed that EPS significantly prompted nuclear factor (NF)-κB subunit p65 translocation, IκB-α protein degradation, and p38 mitogen-activated protein kinase (MAPK) phosphorylation. And the production of IL-12p70 was significantly decreased in condition of the inhibition of p38 or NF-κB signaling pathway. These findings suggested that EPS could induce DCs maturation through both p38 MAPK and NF-κB signaling pathways.

  14. Surfactin induces maturation of dendritic cells in vitro

    PubMed Central

    Xu, Wenwen; Liu, Haofei; Wang, Xiaoqing; Yang, Qian

    2016-01-01

    Surfactin has multiple immune activities, such as triggering immune-related defense responses and enhancing humoral and cellular immune responses. Although, the mechanisms are still unclear. The maturation of dendritic cells (DCs) is essential for inducing downstream immune response. To shed light on the mechanisms of surfactin-induced immune activities, we verified the influences of surfactin on DCs maturation. The results showed that after stimulated with 20 μg/ml surfactin for 24 h, DCs were conferred morphologic and phenotypic characteristics of a mature state, showing an increased shape index and up-regulated expressions of major histocompatibility complex II (MHCII) and CD40. Moreover, surfactin also induced DCs to release IL-6 and tumour necrosis factor-α (TNF-α), indicating that DCs were functionally mature. In addition, the IκB-α level in surfactin-treated DCs was significantly reduced whereas the nuclear p65 level was notably increased, preliminarily indicating that nuclear factor-kappa B (NF-κB) signalling pathway might play an important role in surfactin-induced DCs maturation. PMID:27534429

  15. Rotavirus activates dendritic cells derived from umbilical cord blood monocytes.

    PubMed

    Rosales-Martinez, D; Gutierrez-Xicotencatl, L; Badillo-Godinez, O; Lopez-Guerrero, D; Santana-Calderon, A; Cortez-Gomez, R; Ramirez-Pliego, O; Esquivel-Guadarrama, F

    2016-10-01

    Rotavirus is the most common cause of acute infectious diarrhea in human neonates and infants. However, the studies aimed at dissecting the anti-virus immune response have been mainly performed in adults. Dendritic cells (DCs) play a crucial role in innate and acquired immune responses. Therefore, it is very important to determine the response of neonatal and infant DCs to rotavirus and to compare it to the response of adult DCs. Thus, we determined the response of monocyte-derived DCs from umbilical cord blood (UCB) and adult peripheral blood (PB) to rotavirus in vitro. It was found that the rotavirus and its genome, composed of segmented doubled stranded RNA (dsRNA), induced the activation of neonatal DCs, as these cells up-regulated the levels of CD40, CD86, MHC II, TLR-3 and TLR-4, the production of cytokines IL-6, IL-12/23p40, IL-10, TGF-β (but not of IL-12p70), and the message for TNF-α and IFN-β. This activation enabled the neonatal DCs to induce a strong proliferation of allogeneic CD4(+) T cells and the production of IFN-γ. Moreover, neonatal DCs could be infected by rotavirus and sustain its replication. Neonatal DCs had a similar response as adult DCs towards rotavirus and its genome. However, adult DCs had a biased pro-inflammatory response compared to neonatal DCs, which showed a biased regulatory profile, as they produced higher levels of IL-10 and TGF-β, and were less efficient in inducing a Th1 type response. So it can be concluded that rotavirus and its genome can induce the activation of neonatal DCs in spite of their tolerogenic bias.

  16. Molecular Characterization of Dendritic Cell-Derived Exosomes

    PubMed Central

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

    1999-01-01

    Exosomes are membrane vesicles secreted by hematopoietic cells upon fusion of late multivesicular endosomes with the plasma membrane. Dendritic cell (DC)-derived exosomes induce potent antitumor immune responses in mice, resulting in the regression of established tumors (Zitvogel, L., A. Regnault, A. Lozier, J. Wolfers, C. Flament, D. Tenza, P. Ricciardi-Castagnoli, G. Raposo, and S. Amigorena. 1998. Nat. Med. 4:594–600). To unravel the molecular basis of exosome-induced immune stimulation, we now analyze the regulation of their production during DC maturation and characterize extensively their protein composition by peptide mass mapping. Exosomes contain several cytosolic proteins (including annexin II, heat shock cognate protein hsc73, and heteromeric G protein Gi2α), as well as different integral or peripherally associated membrane proteins (major histocompatiblity complex class II, Mac-1 integrin, CD9, milk fat globule-EGF-factor VIII [MFG-E8]). MFG-E8, the major exosomal component, binds integrins expressed by DCs and macrophages, suggesting that it may be involved in exosome targeting to these professional antigen-presenting cells. Another exosome component is hsc73, a cytosolic heat shock protein (hsp) also present in DC endocytic compartments. hsc73 was shown to induce antitumor immune responses in vivo, and therefore could be involved in the exosome's potent antitumor effects. Finally, exosome production is downregulated upon DC maturation, indicating that in vivo, exosomes are produced by immature DCs in peripheral tissues. Thus, DC-derived exosomes accumulate a defined subset of cellular proteins reflecting their endosomal biogenesis and accounting for their biological function. PMID:10545503

  17. Haemophilus ducreyi partially activates human myeloid dendritic cells.

    PubMed

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

    2007-12-01

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

  18. Clinical grade of generation of dendritic cells for immunotherapy.

    PubMed

    Tang, Duozhuang; Tao, Si; Cao, Yang; Zhou, Jianfeng; Ma, Ding; Huang, Wei

    2007-06-01

    In order to develop a protocol for clinical grade generation of dendritic cells (DCs) for cancer immunotherapy, aphereses were performed with the continuous flow cell separator and materials were derived from 10 leukemia patients that had achieved complete remission. Peripheral blood monocytes were cultured in vitro with GM-CSF, IL-4 for 6 days, then TNF-(the TNF-group) or TNF-, IL-1, IL-6, PGE2 (the cytokine mixture group) were added to promote maturation. Cell number was counted by hematology analyzer, and phenotype study (CD1a, CD14, CD83) was carried out by flow cytometry, and the function of DCs was examined by mixed lymphocyte reaction. The results showed that (0.70+/-0.13)x10(7)/mL (the TNF-alpha group) and (0.79+/-0.04)x10(7)/mL (the cytokine mixture group) DCs were generated respectively in peripheral blood obtained by leucapheresis. The phenotypes were as follows: CD1a+ (74.65+/-4.45)%, CD83+ (39.50+/-4.16)%, CD14+ (2.90+/-1.76)% in TNF-alpha group, and CD1a+ (81.86+/-5.87)%, CD83+ (81.65+/-6.36)%, CD14+ (2.46+/-1.68)% in the cytokine mixture group. It was concluded that leucapheresis may be a feasible way to provide large number of peripheral blood monocytes for DC generation, and combined administration of TNF-, IL-1, IL-6, and PGE2 may greatly promote maturity.

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

    PubMed

    Karouni, Mirna; Kurban, Mazen; Abbas, Ossama

    2016-09-01

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

  20. Regulation of AMPA and NMDA receptor-mediated EPSPs in dendritic trees of thalamocortical cells

    PubMed Central

    Lajeunesse, Francis; Kröger, Helmut

    2013-01-01

    Two main excitatory synapses are formed at the dendritic arbor of first-order nuclei thalamocortical (TC) neurons. Ascending sensory axons primarily establish contacts at large proximal dendrites, whereas descending corticothalamic fibers form synapses on thin distal dendrites. With the use of a multicomparment computational model based on fully reconstructed TC neurons from the ventroposterolateral nucleus of the cat, we compared local responses at the site of stimulation as well as somatic responses induced by both α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)- and N-methyl-d-aspartate receptor (NMDAR)-mediated currents. We found that AMPAR-mediated responses, when synapses were located at proximal dendrites, induced a larger depolarization at the level of soma, whereas NMDAR-mediated responses were more efficient for synapses located at distal dendrites. The voltage transfer and transfer impedance were higher for NMDAR than for AMPAR activation at any location. For both types of synaptic current and for both input locations at the dendritic arbor, somatic responses were characterized by a low variability despite the large variability found in local responses in dendrites. The large neurons had overall smaller somatic responses than small neurons, but this relation was not found in local dendritic responses. We conclude that in TC cells, the dendritic location of small synaptic inputs does not play a major role in the amplitude of a somatic response, but the size of the neuron does. The variability of response amplitude between cells was much larger than the variability within cells. This suggests possible functional segregation of TC neurons of different size. PMID:23100131

  1. Mapping the accumulation of co-infiltrating CNS dendritic cells and encephalitogenic T cells during EAE

    PubMed Central

    Clarkson, Benjamin D; Walker, Alec; Harris, Melissa; Rayasam, Aditya; Sandor, Matyas; Fabry, Zsuzsanna

    2014-01-01

    Evidence from experimental autoimmune encephalomyelitis (EAE) suggests that CNS-infiltrating dendritic cells (DCs) are crucial for restimulation of coinfiltrating T cells. Here we systematically quantified and visualized the distribution and interaction of CNS DCs and T cells during EAE. We report marked periventricular accumulation of DCs and myelin-specific T cells during EAE disease onset prior to accumulation in the spinal cord, indicating that the choroid plexus-CSF axis is a CNS entry portal. Moreover, despite emphasis on spinal cord inflammation in EAE and in correspondence with MS pathology, inflammatory lesions containing interacting DCs and T cells are present in specific brain regions. PMID:25288303

  2. Phenotype and Function of CD209+ Bovine Blood Dendritic Cells, Monocyte-Derived-Dendritic Cells and Monocyte-Derived Macrophages

    PubMed Central

    Bannantine, John P.; Mack, Victoria; Fry, Lindsay M.; Davis, William C.

    2016-01-01

    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 and function: conventional DC (cDC1 and cDC2), plasmacytoid DC (pDC), and monocyte derived DC (MoDC). DC of Artiodactyla (pigs and ruminants) can also be sub-classified using this system, allowing direct functional and phenotypic comparison of MoDC and other DC subsets trafficking in blood (bDC). Because of the high volume of blood collections required to study DC, cattle offer the best opportunity to further our understanding of bDC and MoDC function in an outbred large animal species. As reported here, phenotyping DC using a monoclonal antibody (mAb) to CD209 revealed CD209 is expressed on the major myeloid population of DC present in blood and MoDC, providing a phenotypic link between these two subsets. Additionally, the present study demonstrates that CD209 is also expressed on monocyte derived macrophages (MoΦ). Functional analysis revealed each of these populations can take up and process antigens (Ags), present them to CD4 and CD8 T cells, and elicit a T-cell recall response. Thus, bDC, MoDC, and MoΦ pulsed with pathogens or candidate vaccine antigens can be used to study factors that modulate DC-driven T-cell priming and differentiation ex vivo. PMID:27764236

  3. The microRNA bantam functions in epithelial cells to regulate scaling growth of dendrite arbors in drosophila sensory neurons.

    PubMed

    Parrish, Jay Z; Xu, Peizhang; Kim, Charles C; Jan, Lily Yeh; Jan, Yuh Nung

    2009-09-24

    In addition to establishing dendritic coverage of the receptive field, neurons need to adjust their dendritic arbors to match changes of the receptive field. Here, we show that dendrite arborization (da) sensory neurons establish dendritic coverage of the body wall early in Drosophila larval development and then grow in precise proportion to their substrate, the underlying body wall epithelium, as the larva more than triples in length. This phenomenon, referred to as scaling growth of dendrites, requires the function of the microRNA (miRNA) bantam (ban) in the epithelial cells rather than the da neurons themselves. We further show that ban in epithelial cells dampens Akt kinase activity in adjacent neurons to influence dendrite growth. This signaling between epithelial cells and neurons receiving sensory input from the body wall synchronizes their growth to ensure proper dendritic coverage of the receptive field.

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

    PubMed Central

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

    2016-01-01

    Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response. PMID:27127520

  5. Conditional control of dendritic cell factor 1 expression by a tetracycline-inducible system.

    PubMed

    Yan, H; Huang, C; Yang, M; Guo, J; Wang, J; Feng, R; Wen, T

    2015-05-08

    Dendritic cell factor 1 plays important roles in neural stem cells differentiation and in glioma cells proliferation, migration, and invasion. Here, we used a tetracycline—inducible system that regulates the expression of Dendritic cell factor 1 in glioma cells. We constructed two tet—inducible vectors, pTRE—EGFP—DCF1 and pTRE—LJM1—DCF1, by modifying the promoter PCMV. In the absence of tetracycline or doxycycline, the expression of Dendritic cell factor 1 in cells co—transfected with pTRE—EGFP—DCF1 or pTRE—LJM1—EGFP—DCF1 and ptTS—Neo was suppressed through binding of the tetracyline—controlled transcriptional suppressor to tetracycline response element, and the suppression was released by the addition of doxycycline. Our work has laid foundations for potential clinical application of cancer therapy in realizing artificial regulation of gene.

  6. BDNF over-expression increases olfactory bulb granule cell dendritic spine density in vivo

    PubMed Central

    McDole, Brittnee; Isgor, Ceylan; Pare, Christopher; Guthrie, Kathleen

    2015-01-01

    Olfactory bulb granule cells are axon-less, inhibitory interneurons that regulate the activity of the excitatory output neurons, the mitral and tufted cells, through reciprocal dendrodendritic synapses located on granule cell spines. These contacts are established in the distal apical dendritic compartment, while granule cell basal dendrites and more proximal apical segments bear spines that receive glutamatergic inputs from the olfactory cortices. This synaptic connectivity is vital to olfactory circuit function and is remodeled during development, and in response to changes in sensory activity and lifelong granule cell neurogenesis. Manipulations that alter levels of the neurotrophin brain-derived neurotrophic factor (BDNF) in vivo have significant effects on dendritic spine morphology, maintenance and activity-dependent plasticity for a variety of CNS neurons, yet little is known regarding BDNF effects on bulb granule cell spine maturation or maintenance. Here we show that, in vivo, sustained bulbar over-expression of BDNF produces a marked increase in granule cell spine density that includes an increase in mature spines on their apical dendrites. Morphometric analysis demonstrated that changes in spine density were most notable in the distal and proximal apical domains, indicating that multiple excitatory inputs are potentially modified by BDNF. Our results indicate that increased levels of endogenous BDNF can promote the maturation and/or maintenance of dendritic spines on granule cells, suggesting a role for this factor in modulating granule cell functional connectivity within adult olfactory circuitry. PMID:26211445

  7. Dendritic cell targeting vaccine for HPV-associated cancer

    PubMed Central

    Yin, Wenjie; Duluc, Dorothée; Joo, HyeMee; Oh, SangKon

    2017-01-01

    Dendritic cells (DCs) are major antigen presenting cells that can efficiently prime and activate cellular immune responses. Delivering antigens to in vivo DCs has thus been considered as a promising strategy that could allow us to mount T cell-mediated therapeutic immunity against cancers in patients. Successful development of such types of cancer vaccines that can target in vivo DCs, however, requires a series of outstanding questions that need to be addressed. These include the proper selection of which DC surface receptors, specific DC subsets and DC activators that can further enhance the efficacy of vaccines by promoting effector T cell infiltration and retention in tumors and their actions against tumors. Supplementing these areas of research with additional strategies that can counteract tumor immune evasion mechanisms is also expected to enhance the efficacy of such therapeutic vaccines against cancers. After more than a decade of study, we have concluded that antigen targeting to DCs via CD40 to evoke cellular responses is more efficient than targeting antigens to the same types of DCs via eleven other DC surface receptors tested. In recent work, we have further demonstrated that a prototype vaccine (anti-CD40-HPV16.E6/7, a recombinant fusion protein of anti-human CD40 and HPV16.E6/7 protein) for HPV16-associated cancers can efficiently activate HPV16.E6/7-specific T cells, particularly CD8+ T cells, from the blood of HPV16+ head-and-neck cancer patients. Moreover, anti-CD40-HPV16.E6/7 plus poly(I:C) can mount potent therapeutic immunity against TC-1 tumor expressing HPV16.E6/7 protein in human CD40 transgenic mice. In this manuscript, we thus highlight our recent findings for the development of novel CD40 targeting immunotherapeutic vaccines for HPV16-associated malignancies. In addition, we further discuss several of key questions that still remain to be addressed for enhancing therapeutic immunity elicited by our prototype vaccine against HPV16

  8. 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

  9. Human monocyte-derived dendritic cells turn into foamy dendritic cells with IL-17A1[S

    PubMed Central

    Salvatore, Giulia; Bernoud-Hubac, Nathalie; Bissay, Nathalie; Debard, Cyrille; Daira, Patricia; Meugnier, Emmanuelle; Proamer, Fabienne; Hanau, Daniel; Vidal, Hubert; Aricò, Maurizio; Delprat, Christine; Mahtouk, Karène

    2015-01-01

    Interleukin 17A (IL-17A) is a proinflammatory cytokine involved in the pathogenesis of chronic inflammatory diseases. In the field of immunometabolism, we have studied the impact of IL-17A on the lipid metabolism of human in vitro-generated monocyte-derived dendritic cells (DCs). Microarrays and lipidomic analysis revealed an intense remodeling of lipid metabolism induced by IL-17A in DCs. IL-17A increased 2–12 times the amounts of phospholipids, cholesterol, triglycerides, and cholesteryl esters in DCs. Palmitic (16:0), stearic (18:0), and oleic (18:ln-9c) acid were the main fatty acid chains present in DCs. They were strongly increased in response to IL-17A while their relative proportion remained unchanged. Capture of extracellular lipids was the major mechanism of lipid droplet accumulation, visualized by electron microscopy and Oil Red O staining. Besides this foamy phenotype, IL-17A induced a mixed macrophage-DC phenotype and expression of the nuclear receptor NR1H3/liver X receptor-α, previously identified in the context of atherosclerosis as the master regulator of cholesterol homeostasis in macrophages. These IL-17A-treated DCs were as competent as untreated DCs to stimulate allogeneic naive T-cell proliferation. Following this first characterization of lipid-rich DCs, we propose to call these IL-17A-dependent cells “foamy DCs” and discuss the possible existence of foamy DCs in atherosclerosis, a metabolic and inflammatory disorder involving IL-17A. PMID:25833686

  10. Activation of antitumor cytotoxic T lymphocytes by fusions of human dendritic cells and breast carcinoma cells

    PubMed Central

    Gong, Jianlin; Avigan, David; Chen, Dongshu; Wu, Zekui; Koido, Shigeo; Kashiwaba, Masahiro; Kufe, Donald

    2000-01-01

    We have reported that fusions of murine dendritic cells (DCs) and murine carcinoma cells reverse unresponsiveness to tumor-associated antigens and induce the rejection of established metastases. In the present study, fusions were generated with primary human breast carcinoma cells and autologous DCs. Fusion cells coexpressed tumor-associated antigens and DC-derived costimulatory molecules. The fusion cells also retained the functional potency of DCs and stimulated autologous T cell proliferation. Significantly, the results show that autologous T cells are primed by the fusion cells to induce MHC class I-dependent lysis of autologous breast tumor cells. These findings demonstrate that fusions of human breast cancer cells and DCs activate T cell responses against autologous tumors. PMID:10688917

  11. Functional polarity of dendrites and axons of primate A1 amacrine cells

    PubMed Central

    Davenport, Christopher M.; Detwiler, Peter B.; Dacey, Dennis M.

    2011-01-01

    The A1 cell is an axon-bearing amacrine cell of the primate retina with a diffusely stratified, moderately branched dendritic tree (~400 µm diameter). Axons arise from proximal dendrites forming a second concentric, larger arborization (>4 mm diameter) of thin processes with bouton-like swellings along their length. A1 cells are ON-OFF transient cells that fire a brief high frequency burst of action potentials in response to light (Stafford & Dacey, 1997). It has been hypothesized that A1 cells receive local input to their dendrites, with action potentials propagating output via the axons across the retina, serving a global inhibitory function. To explore this hypothesis we recorded intracellularly from A1 cells in an in vitro macaque monkey retina preparation. A1 cells have an antagonistic center-surround receptive field structure for the ON and OFF components of the light response. Blocking the ON pathway with L-AP4 eliminated ON center responses but not OFF center responses or ON or OFF surround responses. Blocking GABAergic inhibition with picrotoxin increased response amplitudes without affecting receptive field structure. TTX abolished action potentials, with little effect on the sub-threshold light response or basic receptive field structure. We also used multi-photon laser scanning microscopy to record light-induced calcium transients in morphologically identified dendrites and axons of A1 cells. TTX completely abolished such calcium transients in the axons but not in the dendrites. Together these results support the current model of A1 function, whereby the dendritic tree receives synaptic input that determines the center-surround receptive field; and action potentials arise in the axons, which propagate away from the dendritic field across the retina. PMID:17550636

  12. Retrograde plasticity and differential competition of bipolar cell dendrites and axons in the developing retina.

    PubMed

    Johnson, Robert E; Kerschensteiner, Daniel

    2014-10-06

    Most neurons function in the context of pathways that process and propagate information through a series of stages, e.g., from the sensory periphery to cerebral cortex. Because activity at each stage of a neural pathway depends on connectivity at the preceding one, we hypothesized that during development, axonal output of a neuron may regulate synaptic development of its dendrites (i.e., retrograde plasticity). Within pathways, neurons often receive input from multiple partners and provide output to targets shared with other neurons (i.e., convergence). Converging axons can intermingle or occupy separate territories on target dendrites. Activity-dependent competition has been shown to bias target innervation by overlapping axons in several systems. By contrast, whether territorial axons or dendrites compete for targets and inputs, respectively, has not been tested. Here, we generate transgenic mice in which glutamate release from specific sets of retinal bipolar cells (BCs) is suppressed. We find that dendrites of silenced BCs recruit fewer inputs when their neighbors are active and that dendrites of active BCs recruit more inputs when their neighbors are silenced than either active or silenced BCs with equal neighbors. By contrast, axons of silenced BCs form fewer synapses with their targets, irrespective of the activity of their neighbors. These findings reveal that retrograde plasticity guides BC dendritic development in vivo and demonstrate that dendrites, but not territorial axons, in a convergent neural pathway engage in activity-dependent competition. We propose that at a population level, retrograde plasticity serves to maximize functional representation of inputs.

  13. A dendritic nano-sized hexanuclear ruthenium(II) complex as a one- and two-photon luminescent tracking non-viral gene vector

    PubMed Central

    Qiu, Kangqiang; Yu, Bole; Huang, Huaiyi; Zhang, Pingyu; Huang, Juanjuan; Zou, Shanshan; Chen, Yu; Ji, Liangnian; Chao, Hui

    2015-01-01

    Fluorescent tracking gene delivery could provide us with a better understanding of the critical steps in the transfection process. However, for in vivo tracking applications, a small diameter (<10 nm) is one of the rigorous requirements for tracking vectors. Herein, we have demonstrated a new paradigm for two-photon tracking gene delivery based on a dendritic nano-sized hexanuclear ruthenium(II) polypyridyl complex. Because this metallodendrimer has a multivalent periphery, the complex, which is 6.1 nm, showed high stability and excellent dispersibility and could stepwise condense DNA in vitro. With the outstanding photochemical properties of Ru(II) polypyridyl, this complex could track gene delivery in vivo using one- and two-photon imaging. PMID:26185052

  14. Expression of CD86 on human marrow CD34(+) cells identifies immunocompetent committed precursors of macrophages and dendritic cells.

    PubMed

    Ryncarz, R E; Anasetti, C

    1998-05-15

    Macrophages and dendritic cells derive from a hematopoietic stem cell and the existence of a common committed progenitor has been hypothesized. We have recently found in normal human marrow a subset of CD34(+) cells that constitutively expresses HLA-DR and low levels of CD86, a natural ligand for the T cell costimulation receptor CD28. This CD34(+) subset can elicit responses from allogeneic T cells. In this study, we show that CD34(+)/CD86(+) cells can also present tetanus toxoid antigen to memory CD4(+) T cells. CD86 is expressed at low levels in macrophages and high levels in dendritic cells. Therefore, we have tested the hypothesis that CD34(+)/CD86(+) cells are the common precursors of both macrophages and dendritic cells. CD34(+)/CD86(+) marrow cells cultured in granulocyte-macrophage colony-stimulating factor (GM-CSF)-generated macrophages. In contrast, CD34(+)/CD86(-) cells cultured in GM-CSF generated a predominant population of granulocytes. CD34(+)/CD86(+) cells cultured in GM-CSF plus tumor necrosis factor-alpha (TNF-alpha) generated almost exclusively CD1a+/CD83(+) dendritic cells. In contrast, CD34(+)/CD86(-) cells cultured in GM-CSF plus TNF-alpha generated a variety of cell types, including a small population of dendritic cells. In addition, CD34(+)/CD86(+) cells cultured in granulocyte colony-stimulating factor failed to generate CD15(+) granulocytes. Therefore, CD34(+)/CD86(+) cells are committed precursors of both macrophages and dendritic cells. The ontogeny of dendritic cells was recapitulated by stimulation of CD34(+)/CD86(-) cells with TNF-alpha that induced expression of CD86. Subsequent costimulation of CD86(+) cells with GM-CSF plus TNF-alpha lead to expression of CD83 and produced terminal dendritic cell differentiation. Thus, expression of CD86 on hematopoietic progenitor cells is regulated by TNF-alpha and denotes differentiation towards the macrophage or dendritic cell lineages.

  15. Dendritic cell immunotherapy versus bevacizumab plus irinotecan in recurrent malignant glioma patients: a survival gain analysis

    PubMed Central

    Artene, Stefan-Alexandru; Turcu-Stiolica, Adina; Hartley, Richard; Ciurea, Marius Eugen; Daianu, Oana; Brindusa, Corina; Alexandru, Oana; Tataranu, Ligia Gabriela; Purcaru, Stefana Oana; Dricu, Anica

    2016-01-01

    Background The bevacizumab and irinotecan protocol is considered a standard treatment regimen for recurrent malignant glioma. Recent advances in immunotherapy have hinted that vaccination with dendritic cells could become an alternative salvage therapy for the treatment of recurrent malignant glioma. Methods A search was performed on PubMed, Cochrane Library, Web of Science, ScienceDirect, and Embase in order to identify studies with patients receiving bevacizumab plus irinotecan or dendritic cell therapy for recurrent malignant gliomas. The data obtained from these studies were used to perform a systematic review and survival gain analysis. Results Fourteen clinical studies with patients receiving either bevacizumab plus irinotecan or dendritic cell vaccination were identified. Seven studies followed patients that received bevacizumab plus irinotecan (302 patients) and seven studies included patients that received dendritic cell immunotherapy (80 patients). For the patients who received bevacizumab plus irinotecan, the mean reported median overall survival was 7.5 (95% confidence interval [CI] 4.84–10.16) months. For the patients who received dendritic cell immunotherapy, the mean reported median overall survival was 17.9 (95% CI 11.34–24.46) months. For irinotecan + bevacizumab group, the mean survival gain was −0.02±2.00, while that for the dendritic cell immunotherapy group was −0.01±4.54. Conclusion For patients with recurrent malignant gliomas, dendritic cell immunotherapy treatment does not have a significantly different effect when compared with bevacizumab and irinotecan in terms of survival gain (P=0.535) and does not improve weighted survival gain (P=0.620). PMID:27877052

  16. 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.

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

    PubMed Central

    Fillatreau, Simon

    2014-01-01

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

  18. Aeroallergen challenge promotes dendritic cell proliferation in the airways.

    PubMed

    Veres, Tibor Z; Voedisch, Sabrina; Spies, Emma; Valtonen, Joona; Prenzler, Frauke; Braun, Armin

    2013-02-01

    Aeroallergen provocation induces the rapid accumulation of CD11c(+)MHC class II (MHC II)(+) dendritic cells (DCs) in the lungs, which is driven by an increased recruitment of blood-derived DC precursors. Recent data show, however, that well-differentiated DCs proliferate in situ in various tissues. This may also contribute to their allergen-induced expansion; therefore, we studied DC proliferation in the airways of mice in the steady state and after local aeroallergen provocation. Confocal whole-mount microscopy was used to visualize proliferating DCs in different microanatomical compartments of the lung. We demonstrate that in the steady state, CD11c(+)MHC II(+) DCs proliferate in both the epithelial and subepithelial layers of the airway mucosa as well as in the lung parenchyma. A 1-h pulse of the nucleotide 5-ethynyl-2'-deoxyuridine was sufficient to label 5% of DCs in both layers of the airway mucosa. On the level of whole-lung tissue, 3-5% of both CD11b(+) and CD11b(-) DC populations and 0.3% of CD11c(+)MHC II(low) lung macrophages incorporated 5-ethynyl-2'-deoxyuridine. Aeroallergen provocation caused a 3-fold increase in the frequency of locally proliferating DCs in the airway mucosa. This increase in mucosal DC proliferation was later followed by an elevation in the number of DCs. The recruitment of monocyte-derived inflammatory DCs contributed to the increasing number of DCs in the lung parenchyma, but not in the airway mucosa. We conclude that local proliferation significantly contributes to airway DC homeostasis in the steady state and that it is the major mechanism underlying the expansion of the mucosal epithelial/subepithelial DC network in allergic inflammation.

  19. Autologous tolerogenic dendritic cells for rheumatoid and inflammatory arthritis

    PubMed Central

    Bell, G M; Anderson, A E; Diboll, J; Reece, R; Eltherington, O; Harry, R A; Fouweather, T; MacDonald, C; Chadwick, T; McColl, E; Dunn, J; Dickinson, A M; Hilkens, C M U; Isaacs, John D

    2017-01-01

    Objectives To assess the safety of intra-articular (IA) autologous tolerogenic dendritic cells (tolDC) in patients with inflammatory arthritis and an inflamed knee; to assess the feasibility and acceptability of the approach and to assess potential effects on local and systemic disease activities. Methods An unblinded, randomised, controlled, dose escalation Phase I trial. TolDC were differentiated from CD14+ monocytes and loaded with autologous synovial fluid as a source of autoantigens. Cohorts of three participants received 1×106, 3×106 or 10×106 tolDC arthroscopically following saline irrigation of an inflamed (target) knee. Control participants received saline irrigation only. Primary outcome was flare of disease in the target knee within 5 days of treatment. Feasibility was assessed by successful tolDC manufacture and acceptability via patient questionnaire. Potential effects on disease activity were assessed by arthroscopic synovitis score, disease activity score (DAS)28 and Health Assessment Questionnaire (HAQ). Immunomodulatory effects were sought in peripheral blood. Results There were no target knee flares within 5 days of treatment. At day 14, arthroscopic synovitis was present in all participants except for one who received 10×106 tolDC; a further participant in this cohort declined day 14 arthroscopy because symptoms had remitted; both remained stable throughout 91 days of observation. There were no trends in DAS28 or HAQ score or consistent immunomodulatory effects in peripheral blood. 9 of 10 manufactured products met quality control release criteria; acceptability of the protocol by participants was high. Conclusion IA tolDC therapy appears safe, feasible and acceptable. Knee symptoms stabilised in two patients who received 10×106 tolDC but no systemic clinical or immunomodulatory effects were detectable. Trial registration number NCT01352858. PMID:27117700

  20. Cigarette Smoke Decreases the Maturation of Lung Myeloid Dendritic Cells

    PubMed Central

    Calero-Acuña, Carmen; Moreno-Mata, Nicolás; Gómez-Izquierdo, Lourdes; Sánchez-López, Verónica; López-Ramírez, Cecilia; Tobar, Daniela; López-Villalobos, José Luis; Gutiérrez, Cesar; Blanco-Orozco, Ana; López-Campos, José Luis

    2016-01-01

    Background Conflicting data exist on the role of pulmonary dendritic cells (DCs) and their maturation in patients with chronic obstructive pulmonary disease (COPD). Herein, we investigated whether disease severity and smoking status could affect the distribution and maturation of DCs in lung tissues of patients undergoing elective pneumectomy or lobectomy for suspected primary lung cancer. Materials and Methods A total of 75 consecutive patients were included. Spirometry testing was used to identify COPD. Lung parenchyma sections anatomically distant from the primary lesion were examined. We used flow cytometry to identify different DCs subtypes—including BDCA1-positive myeloid DCs (mDCs), BDCA3-positive mDCs, and plasmacytoid DCs (pDCs)—and determine their maturation markers (CD40, CD80, CD83, and CD86) in all participants. We also identified follicular DCs (fDCs), Langerhans DCs (LDCs), and pDCs in 42 patients by immunohistochemistry. Results COPD was diagnosed in 43 patients (16 current smokers and 27 former smokers), whereas the remaining 32 subjects were classified as non-COPD (11 current smokers, 13 former smokers, and 8 never smokers). The number and maturation of DCs did not differ significantly between COPD and non-COPD patients. However, the results of flow cytometry indicated that maturation markers CD40 and CD83 of BDCA1-positive mDCs were significantly decreased in smokers than in non-smokers (P = 0.023 and 0.013, respectively). Immunohistochemistry also revealed a lower number of LDCs in COPD patients than in non-COPD subjects. Conclusions Cigarette smoke, rather than airflow limitation, is the main determinant of impaired DCs maturation in the lung. PMID:27058955

  1. IPC: professional type 1 interferon-producing cells and plasmacytoid dendritic cell precursors.

    PubMed

    Liu, Yong-Jun

    2005-01-01

    Type 1 interferon-(alpha, beta, omega)-producing cells (IPCs), also known as plasmacytoid dendritic cell precursors (pDCs), represent 0.2%-0.8% of peripheral blood mononuclear cells in both humans and mice. IPCs display plasma cell morphology, selectively express Toll-like receptor (TLR)-7 and TLR9, and are specialized in rapidly secreting massive amounts of type 1 interferon following viral stimulation. IPCs can promote the function of natural killer cells, B cells, T cells, and myeloid DCs through type 1 interferons during an antiviral immune response. At a later stage of viral infection, IPCs differentiate into a unique type of mature dendritic cell, which directly regulates the function of T cells and thus links innate and adaptive immune responses. After more than two decades of effort by researchers, IPCs finally claim their place in the hematopoietic chart as the most important cell type in antiviral innate immunity. Understanding IPC biology holds future promise for developing cures for infectious diseases, cancer, and autoimmune diseases.

  2. Blood myeloid and lymphoid dendritic cells reflect Th1/Th2 balance in sarcoidosis and extrinsic allergic alveolitis.

    PubMed

    Buczkowski, Jarosław; Krawczyk, Paweł; Chocholska, Sylwia; Tabarkiewicz, Jacek; Kieszko, Robert; Michnar, Marek; Milanowski, Janusz; Roliński, Jacek

    2003-01-01

    Dendritic cells play a specific regulatory role in the immune system. In this paper, the significance of myeloid and lymphoid dendritic cells in sarcoidosis and extrinsic allergic alveolitis (EAA) was evaluated. Myeloid dendritic cells are connected with Th1 type of immunological response, whereas lymphoid ones--with Th2 type. The latest findings indicate that both diseases are characterized by serious disturbances of Th1/Th2 response to Th1 dominance. Our studies seem to confirm these suggestions. In the peripheral blood of patients with sarcoidosis as well as with EAA, myeloid dendritic cells outnumbered lymphoid ones.

  3. A Case of Blastic Plasmacytoid Dendritic Cell Neoplasm Extensively Studied by Flow Cytometry and Immunohistochemistry

    PubMed Central

    Cesana, Clara; Cittone, Micol Giulia; Bandiera, Laura; Scarpati, Barbara; Mancini, Valentina; Soriani, Silvia; Veronese, Silvio; Truini, Mauro; Rossini, Silvano; Cairoli, Roberto

    2017-01-01

    Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy with aggressive clinical course and poor prognosis. Diagnosis is based on detection of CD4+ CD56+, CD123high, TCL-1+, and blood dendritic cell antigen-2/CD303+ blasts, together with the absence of lineage specific antigens on tumour cells. In this report we present a case of BPDCN presenting with extramedullary and bone marrow involvement, extensively studied by flow cytometry and immunohistochemistry, who achieved complete remission after acute lymphoblastic leukemia like chemotherapy and allogeneic hematopoietic stem cell transplantation.

  4. Clinical trials of dendritic cell-based cancer vaccines in hematologic malignancies

    PubMed Central

    Pyzer, Athalia R; Avigan, David E; Rosenblatt, Jacalyn

    2015-01-01

    The potential for the immune system to target hematological malignancies is demonstrated in the allogeneic transplant setting, where durable responses can be achieved. However, allogeneic transplantation is associated with significant morbidity and mortality related to graft versus host disease. Cancer immunotherapy has the capacity to direct a specific cytotoxic immune response against cancer cells, particularly residual cancer cells, in order to reduce the likelihood of disease relapse in a more targeted and tolerated manner. Ex vivo dendritic cells can be primed in various ways to present tumor associated antigen to the immune system, in the context of co-stimulatory molecules, eliciting a tumor specific cytotoxic response in patients. Several approaches to prime dendritic cells and overcome the immunosuppressive microenvironment have been evaluated in pre-clinical and early clinical trials with promising results. In this review, we summarize the clinical data evaluating dendritic cell based vaccines for the treatment of hematological malignancies. PMID:25625926

  5. Ia antigens are expressed on ATPase-positive dendritic cells in chicken epidermis.

    PubMed Central

    Pérez Torres, A; Millan Aldaco, D A

    1994-01-01

    Langerhans cells (LC) are antigen-presenting dendritic cells located in mammalian epidermis and in other stratified epithelia. We recently demonstrated the presence of Langerhans-like cells in the epidermis of the chicken using ultrastructural histochemistry for adenosine triphosphatase (ATPase). The aim of the present study was to test whether ATPase-positive dendritic cells also express class II histocompatibility molecules (Ia antigens) encoded by the major histocompatibility complex (MHC), using a double staining technique, in separated chicken epidermal sheets. We concluded that the epidermal dendritic cells observed are the LC of the chicken, based on their morphology and spatial distribution, but mainly on the complete overlap for ATPase reaction and Ia antigen expression, these being reliable markers for the identification of mammalian LC. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Figs 7,8 Figs 9,10 Figs 11,12 PMID:7928646

  6. Differential dendritic Ca2+ signalling in young and mature hippocampal granule cells

    PubMed Central

    Stocca, Gabriella; Schmidt-Hieber, Christoph; Bischofberger, Josef

    2008-01-01

    Neuronal activity is critically important for development and plasticity of dendrites, axons and synaptic connections. Although Ca2+ is an important signal molecule for these processes, not much is known about the regulation of the dendritic Ca2+ concentration in developing neurons. Here we used confocal Ca2+ imaging to investigate dendritic Ca2+ signalling in young and mature hippocampal granule cells, identified by the expression of the immature neuronal marker polysialated neural cell adhesion molecule (PSA-NCAM). Using the Ca2+-sensitive fluorescent dye OGB-5N, we found that both young and mature granule cells showed large action-potential evoked dendritic Ca2+ transients with similar amplitude of ∼200 nm, indicating active backpropagation of action potentials. However, the decay of the dendritic Ca2+ concentration back to baseline values was substantially different with a decay time constant of 550 ms in young versus 130 ms in mature cells, leading to a more efficient temporal summation of Ca2+ signals during theta-frequency stimulation in the young neurons. Comparison of the peak Ca2+ concentration and the decay measured with different Ca2+ indicators (OGB-5N, OGB-1) in the two populations of neurons revealed that the young cells had an ∼3 times smaller endogenous Ca2+-binding ratio (∼75 versus∼220) and an ∼10 times slower Ca2+ extrusion rate (∼170 s−1versus∼1800 s−1). These data suggest that the large dendritic Ca2+ signals due to low buffer capacity and slow extrusion rates in young granule cells may contribute to the activity-dependent growth and plasticity of dendrites and new synaptic connections. This will finally support differentiation and integration of young neurons into the hippocampal network. PMID:18591186

  7. Olfactory experiences dynamically regulate plasticity of dendritic spines in granule cells of Xenopus tadpoles in vivo

    PubMed Central

    Zhang, Li; Huang, Yubin; Hu, Bing

    2016-01-01

    Granule cells, rich in dendrites with densely punctated dendritic spines, are the most abundant inhibitory interneurons in the olfactory bulb. The dendritic spines of granule cells undergo remodeling during the development of the nervous system. The morphological plasticity of the spines’ response to different olfactory experiences in vivo is not fully known. In initial studies, a single granule cell in Xenopus tadpoles was labeled with GFP plasmids via cell electroporation; then, morphologic changes of the granule cell spines were visualized by in vivo confocal time-lapse imaging. With the help of long-term imaging, the total spine density, dynamics, and stability of four types of dendritic spines (mushroom, stubby, thin and filopodia) were obtained. Morphological analysis demonstrated that odor enrichment produced a remarkable increase in the spine density and stability of large mushroom spine. Then, with the help of short-term imaging, we analyzed the morphological transitions among different spines. We found that transitions between small spines (thin and filopodia) were more easily influenced by odor stimulation or olfactory deprivation. These results indicate that different olfactory experiences can regulate the morphological plasticity of different dendritic spines in the granule cell. PMID:27713557

  8. Nanostructured lipid carriers loaded with resveratrol modulate human dendritic cells

    PubMed Central

    Barbosa, João P; Neves, Ana R; Silva, Andreia M; Barbosa, Mário A; Reis, M Salette; Santos, Susana G

    2016-01-01

    Dendritic cells (DCs) are promising targets for drug delivery, as they can induce immunity or tolerance. The current study aims to examine the potential of using nanostructured lipid carriers (NLC) as delivery systems for human DC by evaluating nanoparticle internalization, cell labeling, and drug activity. NLC were formulated incorporating the fluorochrome fluorescein isothiocyanate (FITC-NLC) or the natural anti-inflammatory molecule resveratrol (rsv-NLC). Primary human DCs were differentiated from peripheral blood monocytes, and the innovative imaging flow cytometry technique was used to examine FITC-NLC internalization. The capacity of rsv-NLC to inhibit DC activation in response to proinflammatory cytokine tumor necrosis factor-α (TNF- α) was investigated by conventional flow cytometry. A combination of imaging and conventional flow cytometry was used to assess NLC cytotoxicity. The results obtained indicate that both NLC formulations were stable over time, with mean diameter <200 nm and highly negative zeta potential (about −30 mV). When DCs were placed in contact with NLC, imaging flow cytometry clearly showed that DCs efficiently internalized FITC-NLC, with nearly 100% of cells internalizing nanoparticles upon 1 hour of incubation. Both immature and mature DCs internalized NLC to high and comparable levels, and without cytotoxicity. Stimulating DC with TNF-α in the presence of rsv-NLC revealed that, using these nanoparticles, very small concentrations of rsv were sufficient to significantly decrease surface expression of activation marker CD83 (5 µM) and major histocompatibility complex-class II molecule human leukocyte antigen – antigen D related (10 µM), both upregulated in response to TNF-α stimulation. Rsv-NLC were compared with free rsv; at 5 µM, rsv-NLC were able to inhibit nuclear factor κ beta phosphorylation and significantly decrease the level of interleukin-12/23, both upregulated in response to TNF-α, while 10 µM free rsv were

  9. Spatiotemporally separated antigen uptake by alveolar dendritic cells and airway presentation to T cells in the lung

    PubMed Central

    Thornton, Emily E.; Looney, Mark R.; Bose, Oishee; Sen, Debasish; Sheppard, Dean; Locksley, Richard; Huang, Xiaozhu

    2012-01-01

    Asthma pathogenesis is focused around conducting airways. The reasons for this focus have been unclear because it has not been possible to track the sites and timing of antigen uptake or subsequent antigen presentation to effector T cells. In this study, we use two-photon microscopy of the lung parenchyma and note accumulation of CD11b+ dendritic cells (DCs) around the airway after allergen challenge but very limited access of these airway-adjacent DCs to the contents of the airspace. In contrast, we observed prevalent transepithelial uptake of particulate antigens by alveolar DCs. These distinct sites are temporally linked, as early antigen uptake in alveoli gives rise to DC and antigen retention in the airway-adjacent region. Antigen-specific T cells also accumulate in the airway-adjacent region after allergen challenge and are activated by the accumulated DCs. Thus, we propose that later airway hyperreactivity results from selective retention of allergen-presenting DCs and antigen-specific T cells in airway-adjacent interaction zones, not from variation in the abilities of individual DCs to survey the lung. PMID:22585735

  10. 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.

  11. The yin and yang of intestinal epithelial cells in controlling dendritic cell function

    PubMed Central

    Iliev, Iliyan D.; Matteoli, Gianluca; Rescigno, Maria

    2007-01-01

    Recent work suggests that dendritic cells (DCs) in mucosal tissues are “educated” by intestinal epithelial cells (IECs) to suppress inflammation and promote immunological tolerance. After attack by pathogenic microorganisms, however, “non-educated” DCs are recruited from nearby areas, such as the dome of Peyer's patches (PPs) and the blood, to initiate inflammation and the ensuing immune response to the invader. Differential epithelial cell (EC) responses to commensals and pathogens may control these two tolorogenic and immunogenic functions of DCs. PMID:17893197

  12. Supralinear dendritic Ca2+ signalling in young developing CA1 pyramidal cells

    PubMed Central

    Pohle, Jörg; Bischofberger, Josef

    2014-01-01

    Although Ca2+ is critically important in activity-dependent neuronal development, not much is known about the regulation of dendritic Ca2+ signals in developing neurons. Here, we used ratiometric Ca2+ imaging to investigate dendritic Ca2+ signalling in rat hippocampal pyramidal cells during the first 1–4 weeks of postnatal development. We show that active dendritic backpropagation of Nav channel-dependent action potentials (APs) evoked already large dendritic Ca2+ transients in animals aged 1 week with amplitudes of ∼150 nm, similar to the amplitudes of ∼160 nM seen in animals aged 4 weeks. Although the AP-evoked dendritic Ca2+ load increased about four times during the first 4 weeks, the peak amplitude of free Ca2+ concentration was balanced by a four-fold increase in Ca2+ buffer capacity κs (∼70 vs. ∼280). Furthermore, Ca2+ extrusion rates increased with postnatal development, leading to a slower decay time course (∼0.2 s vs. ∼0.1 s) and more effective temporal summation of Ca2+ signals in young cells. Most importantly, during prolonged theta-burst stimulation dendritic Ca2+ signals were up to three times larger in cells at 1 week than at 4 weeks of age and much larger than predicted by linear summation, which is attributable to an activity-dependent slow-down of Ca2+ extrusion. As Ca2+ influx is four-fold smaller in young cells, the larger Ca2+ signals are generated using four times less ATP consumption. Taken together, the data suggest that active backpropagations regulate dendritic Ca2+ signals during early postnatal development. Remarkably, during prolonged AP firing, Ca2+ signals are several times larger in young than in mature cells as a result of activity-dependent regulation of Ca2+ extrusion rates. PMID:25239458

  13. Stromal fibroblasts support dendritic cells to maintain IL-23/Th17 responses after exposure to ionizing radiation

    PubMed Central

    Malecka, Anna; Wang, Qunwei; Shah, Sabaria; Sutavani, Ruhcha V.; Spendlove, Ian; Ramage, Judith M.; Greensmith, Julie; Franks, Hester A.; Gough, Michael J.; Saalbach, Anja; Patel, Poulam M.; Jackson, Andrew M.

    2016-01-01

    Dendritic cell function is modulated by stromal cells, including fibroblasts. Although poorly understood, the signals delivered through this crosstalk substantially alter dendritic cell biology. This is well illustrated with release of TNF-α/IL-1β from activated dendritic cells, promoting PGE2 secretion from stromal fibroblasts. This instructs dendritic cells to up-regulate IL-23, a key Th17-polarizing cytokine. We previously showed that ionizing radiation inhibited IL-23 production by human dendritic cells in vitro. In the present study, we investigated the hypothesis that dendritic cell-fibroblast crosstalk overcomes the suppressive effect of ionizing radiation to support appropriately polarized Th17 responses. Radiation (1–6 Gy) markedly suppressed IL-23 secretion by activated dendritic cells (P < 0.0001) without adversely impacting their viability and consequently, inhibited the generation of Th17 responses. Cytokine suppression by ionizing radiation was selective, as there was no effect on IL-1β, -6, -10, and -27 or TNF-α and only a modest (11%) decrease in IL-12p70 secretion. Coculture with fibroblasts augmented IL-23 secretion by irradiated dendritic cells and increased Th17 responses. Importantly, in contrast to dendritic cells, irradiated fibroblasts maintained their capacity to respond to TNF-α/IL-1β and produce PGE2, thus providing the key intermediary signals for successful dendritic cell-fibroblasts crosstalk. In summary, stromal fibroblasts support Th17-polarizing cytokine production by dendritic cells that would otherwise be suppressed in an irradiated microenvironment. This has potential ramifications for understanding the immune response to local radiotherapy. These findings underscore the need to account for the impact of microenvironmental factors, including stromal cells, in understanding the control of immunity. PMID:27049023

  14. Full restoration of Brucella-infected dendritic cell functionality through Vγ9Vδ2 T helper type 1 crosstalk.

    PubMed

    Ni, Ming; Martire, Delphine; Scotet, Emmanuel; Bonneville, Marc; Sanchez, Francoise; Lafont, Virginie

    2012-01-01

    Vγ9Vδ2 T cells play an important role in the immune response to infectious agents but the mechanisms contributing to this immune process remain to be better characterized. Following their activation, Vγ9Vδ2 T cells develop cytotoxic activity against infected cells, secrete large amounts of cytokines and influence the function of other effectors of immunity, notably cells playing a key role in the initiation of the adaptive immune response such as dendritic cells. Brucella infection dramatically impairs dendritic cell maturation and their capacity to present antigens to T cells. Herein, we investigated whether V T cells have the ability to restore the full functional capacities of Brucella-infected dendritic cells. Using an in vitro multicellular infection model, we showed that: 1/Brucella-infected dendritic cells activate Vγ9Vδ2 T cells through contact-dependent mechanisms, 2/activated Vγ9Vδ2 T cells induce full differentiation into IL-12 producing cells of Brucella-infected dendritic cells with functional antigen presentation activity. Furthermore, phosphoantigen-activated Vγ9Vδ2 T cells also play a role in triggering the maturation process of dendritic cells already infected for 24 h. This suggests that activated Vγ9Vδ2 T cells could be used to modulate the outcome of infectious diseases by promoting an adjuvant effect in dendritic cell-based cellular therapies.

  15. Liaison between natural killer cells and dendritic cells in human gestation.

    PubMed

    Leno-Durán, Ester; Muñoz-Fernández, Raquel; Olivares, Enrique García; Tirado-González, Irene

    2014-09-01

    A successful pregnancy relies on immunological adaptations that allow the fetus to grow and develop in the uterus, despite being recognized by maternal immune cells. Among several immunocompetent cell types present within the human maternal/fetal interface, DC-SIGN(+) dendritic cells (DCs) and CD56(+) natural killer (NK) cells are of major importance for early pregnancy maintenance, not only generating maternal immunological tolerance but also regulating stromal cell differentiation. Previous reports show the presence of NK-DC cell conjugates in first trimester human decidua, suggesting that these cells may play a role in the modulation of the local immune response within the uterus. While effective immunity is necessary to protect the mother from harmful pathogens, some form of tolerance must be activated to avoid an immune response against fetal antigens. This review article discusses current evidence concerning the functions of DC and NK cells in pregnancy and their liaison in human decidua.

  16. Liaison between natural killer cells and dendritic cells in human gestation

    PubMed Central

    Leno-Durán, Ester; Muñoz-Fernández, Raquel; García Olivares, Enrique; Tirado-González, Irene

    2014-01-01

    A successful pregnancy relies on immunological adaptations that allow the fetus to grow and develop in the uterus, despite being recognized by maternal immune cells. Among several immunocompetent cell types present within the human maternal/fetal interface, DC-SIGN+ dendritic cells (DCs) and CD56+ natural killer (NK) cells are of major importance for early pregnancy maintenance, not only generating maternal immunological tolerance but also regulating stromal cell differentiation. Previous reports show the presence of NK–DC cell conjugates in first trimester human decidua, suggesting that these cells may play a role in the modulation of the local immune response within the uterus. While effective immunity is necessary to protect the mother from harmful pathogens, some form of tolerance must be activated to avoid an immune response against fetal antigens. This review article discusses current evidence concerning the functions of DC and NK cells in pregnancy and their liaison in human decidua. PMID:24954224

  17. Dendritic cells: microbial clearance via autophagy and potential immunobiological consequences for periodontal disease

    PubMed Central

    El-Awady, Ahmed R.; Arce, Roger M.; Cutler, Christopher W.

    2015-01-01

    Dendritic cells are potent antigen-capture and -presenting cells that play a key role in the initiation and regulation of the adaptive immune response. This process of immune homeostasis, as maintained by dendritic cells, is susceptible to dysregulation by certain pathogens during chronic infections. Such dysregulation may lead to disease perpetuation with potentially severe systemic consequences. Here we discuss in detail how intracellular pathogens exploit dendritic cells and evade degradation by altering or evading autophagy. This novel mechanism explains in part the chronic, persistent nature observed in several immuno-inflammatory diseases, including periodontal disease. Also, here we propose a hypothetical model on the plausible role of autophagy in the context of periodontal disease. Promotion of autophagy may open new therapeutic strategies in the search for a “cure” for periodontal disease in humans. PMID:26252408

  18. Maturation and trafficking of monocyte-derived dendritic cells in monkeys: implications for dendritic cell-based vaccines.

    PubMed

    Barratt-Boyes, S M; Zimmer, M I; Harshyne, L A; Meyer, E M; Watkins, S C; Capuano, S; Murphey-Corb, M; Falo, L D; Donnenberg, A D

    2000-03-01

    Human dendritic cells (DC) have polarized responses to chemokines as a function of maturation state, but the effect of maturation on DC trafficking in vivo is not known. We have addressed this question in a highly relevant rhesus macaque model. We demonstrate that immature and CD40 ligand-matured monocyte-derived DC have characteristic phenotypic and functional differences in vitro. In particular, immature DC express CC chemokine receptor 5 (CCR5) and migrate in response to macrophage inflammatory protein-1alpha (MIP-1alpha), whereas mature DC switch expression to CCR7 and respond exclusively to MIP-3beta and 6Ckine. Mature DC transduced to express a marker gene localized to lymph nodes after intradermal injection, constituting 1.5% of lymph node DC. In contrast, cutaneous DC transfected in situ via gene gun were detected in the draining lymph node at a 20-fold lower frequency. Unexpectedly, the state of maturation at the time of injection had no influence on the proportion of DC that localized to draining lymph nodes, as labeled immature and mature DC were detected in equal numbers. Immature DC that trafficked to lymph nodes underwent a significant up-regulation of CD86 expression indicative of spontaneous maturation. Moreover, immature DC exited completely from the dermis within 36 h of injection, whereas mature DC persisted in large numbers associated with a marked inflammatory infiltrate. We conclude that in vitro maturation is not a requirement for effective migration of DC in vivo and suggest that administration of Ag-loaded immature DC that undergo natural maturation following injection may be preferred for DC-based immunotherapy.

  19. Generation of T cell effectors using tumor cell-loaded dendritic cells for adoptive T cell therapy.

    PubMed

    Vavrova, Katerina; Vrabcova, Petra; Filipp, Dominik; Bartunkova, Jirina; Horvath, Rudolf

    2016-12-01

    Adoptive T cell transfer has been shown to be an effective method used to boost tumor-specific immune responses in several types of malignancies. In this study, we set out to optimize the ACT protocol for the experimental treatment of prostate cancer. The protocol includes a pre-stimulation step whereby T cells were primed with autologous dendritic cells loaded with the high hydrostatic pressure-treated prostate cancer cell line, LNCaP. Primed T cells were further expanded in vitro with anti-CD3/CD28 Dynabeads in the WAVE bioreactor 2/10 system and tested for cytotoxicity. Our data indicates that the combination of pre-stimulation and expansion steps resulted in the induction and enrichment of tumor-responsive CD4(+) and CD8(+) T cells at clinically relevant numbers. The majority of both CD4(+) and CD8(+) IFN-γ producing cells were CD62L, CCR7 and CD57 negative but CD28 and CD27 positive, indicating an early antigen experienced phenotype in non-terminal differentiation phase. Expanded T cells showed significantly greater cytotoxicity against LNCaP cells compared to the control SKOV-3, an ovarian cancer line. In summary, our results suggest that the ACT approach together with LNCaP-loaded dendritic cells provides a viable way to generate prostate cancer reactive T cell effectors that are capable of mounting efficient and targeted antitumor responses and can be thus considered for further testing in a clinical setting.

  20. Active Dendrites and Differential Distribution of Calcium Channels Enable Functional Compartmentalization of Golgi Cells

    PubMed Central

    Rudolph, Stephanie; Hull, Court

    2015-01-01

    Interneurons are essential to controlling excitability, timing, and synaptic integration in neuronal networks. Golgi cells (GoCs) serve these roles at the input layer of the cerebellar cortex by releasing GABA to inhibit granule cells (grcs). GoCs are excited by mossy fibers (MFs) and grcs and provide feedforward and feedback inhibition to grcs. Here we investigate two important aspects of GoC physiology: the properties of GoC dendrites and the role of calcium signaling in regulating GoC spontaneous activity. Although GoC dendrites are extensive, previous studies concluded they are devoid of voltage-gated ion channels. Hence, the current view holds that somatic voltage signals decay passively within GoC dendrites, and grc synapses onto distal dendrites are not amplified and are therefore ineffective at firing GoCs because of strong passive attenuation. Using whole-cell recording and calcium imaging in rat slices, we find that dendritic voltage-gated sodium channels allow somatic action potentials to activate voltage-gated calcium channels (VGCCs) along the entire dendritic length, with R-type and T-type VGCCs preferentially located distally. We show that R- and T-type VGCCs located in the dendrites can boost distal synaptic inputs and promote burst firing. Active dendrites are thus critical to the regulation of GoC activity, and consequently, to the processing of input to the cerebellar cortex. In contrast, we find that N-type channels are preferentially located near the soma, and control the frequency and pattern of spontaneous firing through their close association with calcium-activated potassium (KCa) channels. Thus, VGCC types are differentially distributed and serve specialized functions within GoCs. SIGNIFICANCE STATEMENT Interneurons are essential to neural processing because they modulate excitability, timing, and synaptic integration within circuits. At the input layer of the cerebellar cortex, a single type of interneuron, the Golgi cell (GoC), carries

  1. Isolation and Culture of Embryonic Stem Cells, Mesenchymal Stem Cells, and Dendritic Cells from Humans and Mice.

    PubMed

    Kar, Srabani; Mitra, Shinjini; Banerjee, Ena Ray

    2016-01-01

    Stem cells are cells capable of proliferation, self-renewal, and differentiation into specific phenotypes. They are an essential part of tissue engineering, which is used in regenerative medicine in case of degenerative diseases. In this chapter, we describe the methods of isolating and culturing various types of stem cells, like human embryonic stem cells (hESCs), human umbilical cord derived mesenchymal stem cells (hUC-MSCs), murine bone marrow derived mesenchymal stem cells (mBM-MSCs), murine adipose tissue derived mesenchymal stem cells (mAD-MSCs), and murine bone marrow derived dendritic cells (mBMDCs). All these cell types can be used in tissue engineering techniques.

  2. Dendritic cells fused with different pancreatic carcinoma cells induce different T-cell responses

    PubMed Central

    Andoh, Yoshiaki; Makino, Naohiko; Yamakawa, Mitsunori

    2013-01-01

    Background It is unclear whether there are any differences in the induction of cytotoxic T lymphocytes (CTL) and CD4+CD25high regulatory T-cells (Tregs) among dendritic cells (DCs) fused with different pancreatic carcinomas. The aim of this study was to compare the ability to induce cytotoxicity by human DCs fused with different human pancreatic carcinoma cell lines and to elucidate the causes of variable cytotoxicity among cell lines. Methods Monocyte-derived DCs, which were generated from peripheral blood mononuclear cells (PBMCs), were fused with carcinoma cells such as Panc-1, KP-1NL, QGP-1, and KP-3L. The induction of CTL and Tregs, and cytokine profile of PBMCs stimulated by fused DCs were evaluated. Results The cytotoxicity against tumor targets induced by PBMCs cocultured with DCs fused with QGP-1 (DC/QGP-1) was very low, even though PBMCs cocultured with DCs fused with other cell lines induced significant cytotoxicity against the respective tumor target. The factors causing this low cytotoxicity were subsequently investigated. DC/QGP-1 induced a significant expansion of Tregs in cocultured PBMCs compared with DC/KP-3L. The level of interleukin-10 secreted in the supernatants of PBMCs cocultured with DC/QGP-1 was increased significantly compared with that in DC/KP-3L. Downregulation of major histocompatibility complex class I expression and increased secretion of vascular endothelial growth factor were observed with QGP-1, as well as in the other cell lines. Conclusion The present study demonstrated that the cytotoxicity induced by DCs fused with pancreatic cancer cell lines was different between each cell line, and that the reduced cytotoxicity of DC/QGP-1 might be related to the increased secretion of interleukin-10 and the extensive induction of Tregs. PMID:23378772

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

    PubMed

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

    2011-02-25

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

  4. Paeoniflorin Ameliorates Experimental Autoimmune Encephalomyelitis via Inhibition of Dendritic Cell Function and Th17 Cell Differentiation

    PubMed Central

    Zhang, Han; Qi, Yuanyuan; Yuan, Yuanyang; Cai, Li; Xu, Haiyan; Zhang, Lili; Su, Bing; Nie, Hong

    2017-01-01

    Paeoniflorin (PF) is a monoterpene glycoside and exhibits multiple effects, including anti-inflammation and immunoregulation. To date, the effect of PF on multiple sclerosis (MS) has not been investigated. In this study, we investigated the effect of PF in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. After administered with PF, the onset and clinical symptoms of EAE mice were significantly ameliorated, and the number of Th17 cells infiltrated in central nervous system (CNS) and spleen was also dramatically decreased. Instead of inhibiting the differentiation of Th17 cells directly, PF influenced Th17 cells via suppressing the expression of costimulatory molecules and the production of interlukin-6 (IL-6) of dendritic cells (DCs) in vivo and in vitro, which may be attributable to the inhibition of IKK/NF-κB and JNK signaling pathway. When naïve CD4+ T cells were co-cultured with PF-treated dendritic cells under Th17-polarizing condition, the percentage of Th17 cells and the phosphorylation of STAT3 were decreased, as well as the mRNA levels of IL-17, RORα, and RORγt. Our study provided insights into the role of PF as a unique therapeutic agent for the treatment of multiple sclerosis and illustrated the underlying mechanism of PF from a new perspective. PMID:28165507

  5. [ILT3+/ILT4+ tolerogenic dendritic cells and their influence on allograft survival].

    PubMed

    Arboleda, John F; García, Luis F; Alvarez, Cristiam M

    2011-06-01

    Dendritic cells, the most powerful antigen-presenting cells, are important for triggering of the immune responses to allo-antigens. However, they also play a fundamental role in the peripheral tolerance maintenance. Tolerance is enhanced by the presence on the dendritic cell surface of the inhibitor receptors ILT3 and ILT4. They recruit protein tyrosine-phosphatases to their ITIM domains and inhibit antigen-presenting cell activation, leading T cell hypo-responsivensess. Moreover, these receptors favor a bidirectional interaction with T-suppressor and T-regulator cells, generating an antigen-specific immunoregulator cascade, in which the dendritic cell behaves as a tolerogenic cell. In the current review, analysis is centered on the biology and behavior of the tolerogenic dendritic cells that express high levels of ILT3 and ILT4. Some molecular and genetics aspects of these receptors are discussed as well as their importance in the modulation of the allo-specific antigen immune response to transplants.

  6. Interaction of gold nanoparticles and nickel(II) sulfate affects dendritic cell maturation.

    PubMed

    Deville, Sarah; Baré, Birgit; Piella, Jordi; Tirez, Kristof; Hoet, Peter; Monopoli, Marco P; Dawson, Kenneth A; Puntes, Victor F; Nelissen, Inge

    2016-12-01

    Despite many investigations have focused on the pristine toxicity of gold nanoparticles (GNPs), little is known about the outcome of co-exposure and interaction of GNPs with heavy metals which can possibly detoxify or potentiate them. Here, the combined exposure of nickel (II) sulfate (NiSO4) and GNPs on the maturation response of dendritic cells (DCs) was explored. Exposure to GNPs or NiSO4 separately induced cell activation. When cells were exposed to a mixture of both, however, the observed cell activation pattern indicated a competitive rather than an additive effect of both inducers with levels similar to those induced by NiSO4 alone. Quantification of the GNP uptake by DCs demonstrated a significant decrease in intracellular gold content during co-incubation with NiSO4. An extensive physiochemical characterization was performed to determine the interaction between GNPs and NiSO4 in the complex physiological media using nanoparticle tracking analyses, disc centrifugation, UV-visible spectroscopy, ICP-MS analyses, zeta potential measurements, electron microscopy, and proteomics. Although GNPs and NiSO4 did not directly interact with each other, the presence of NiSO4 in the physiological media resulted in changes in GNPs' charge and their associated protein corona (content and composition), which may contribute to a decreased cellular uptake of GNPs and sustaining the nickel-induced DC maturation. The presented results provide new insights in the interaction of heavy metals and NPs in complex physiological media. Moreover, this study highlights the necessity of mixture toxicology, since these combined exposures are highly relevant for human subjection to NPs and risk assessment of nanomaterials.

  7. Viral infection triggers rapid differentiation of human blood monocytes into dendritic cells.

    PubMed

    Hou, Wanqiu; Gibbs, James S; Lu, Xiuju; Brooke, Christopher B; Roy, Devika; Modlin, Robert L; Bennink, Jack R; Yewdell, Jonathan W

    2012-03-29

    Surprisingly little is known about the interaction of human blood mononuclear cells with viruses. Here, we show that monocytes are the predominant cell type infected when peripheral blood mononuclear cells are exposed to viruses ex vivo. Remarkably, infection with vesicular stomatitis virus, vaccinia virus, and a variety of influenza A viruses (including circulating swine-origin virus) induces monocytes to differentiate within 18 hours into CD16(-)CD83(+) mature dendritic cells with enhanced capacity to activate T cells. Differentiation into dendritic cells does not require cell division and occurs despite the synthesis of viral proteins, which demonstrates that monocytes counteract the capacity of these highly lytic viruses to hijack host cell biosynthetic capacity. Indeed, differentiation requires infectious virus and viral protein synthesis. These findings demonstrate that monocytes are uniquely susceptible to viral infection among blood mononuclear cells, with the likely purpose of generating cells with enhanced capacity to activate innate and acquired antiviral immunity.

  8. Hyperactivation of STAT3 is involved in abnormal differentiation of dendritic cells in cancer.

    PubMed

    Nefedova, Yulia; Huang, Mei; Kusmartsev, Sergei; Bhattacharya, Raka; Cheng, Pingyan; Salup, Raoul; Jove, Richard; Gabrilovich, Dmitry

    2004-01-01

    Abnormal differentiation of myeloid cells is one of the hallmarks of cancer. However, the molecular mechanisms of this process remain elusive. In this study, we investigated the effect of tumor-derived factors on Janus kinase (Jak)/STAT signaling in myeloid cells during their differentiation into dendritic cells. Tumor cell conditioned medium induced activation of Jak2 and STAT3, which was associated with an accumulation of immature myeloid cells. Jak2/STAT3 activity was localized primarily in these myeloid cells, which prevented the differentiation of immature myeloid cells into mature dendritic cells. This differentiation was restored after removal of tumor-derived factors. Inhibition of STAT3 abrogated the negative effects of these factors on myeloid cell differentiation, and overexpression of STAT3 reproduced the effects of tumor-derived factors. Thus, this is a first demonstration that tumor-derived factors may affect myeloid cell differentiation in cancer via constitutive activation of Jak2/STAT3.

  9. Human cytomegalovirus alters localization of MHC class II and dendrite morphology in mature Langerhans cells.

    PubMed

    Lee, Andrew W; Hertel, Laura; Louie, Ryan K; Burster, Timo; Lacaille, Vashti; Pashine, Achal; Abate, Davide A; Mocarski, Edward S; Mellins, Elizabeth D

    2006-09-15

    Hemopoietic stem cell-derived mature Langerhans-type dendritic cells (LC) are susceptible to productive infection by human CMV (HCMV). To investigate the impact of infection on this cell type, we examined HLA-DR biosynthesis and trafficking in mature LC cultures exposed to HCMV. We found decreased surface HLA-DR levels in viral Ag-positive as well as in Ag-negative mature LC. Inhibition of HLA-DR was independent of expression of unique short US2-US11 region gene products by HCMV. Indeed, exposure to UV-inactivated virus, but not to conditioned medium from infected cells, was sufficient to reduce HLA-DR on mature LC, implicating particle binding/penetration in this effect. Reduced surface levels reflected an altered distribution of HLA-DR because total cellular HLA-DR was not diminished. Accumulation of HLA-DR was not explained by altered cathepsin S activity. Mature, peptide-loaded HLA-DR molecules were retained within cells, as assessed by the proportion of SDS-stable HLA-DR dimers. A block in egress was implicated, as endocytosis of surface HLA-DR was not increased. Immunofluorescence microscopy corroborated the intracellular retention of HLA-DR and revealed markedly fewer HLA-DR-positive dendritic projections in infected mature LC. Unexpectedly, light microscopic analyses showed a dramatic loss of the dendrites themselves and immunofluorescence revealed that cytoskeletal elements crucial for the formation and maintenance of dendrites are disrupted in viral Ag-positive cells. Consistent with these dendrite effects, HCMV-infected mature LC exhibit markedly reduced chemotaxis in response to lymphoid chemokines. Thus, HCMV impedes MHC class II molecule trafficking, dendritic projections, and migration of mature LC. These changes likely contribute to the reduced activation of CD4+ T cells by HCMV-infected mature LC.

  10. The dendritic cell receptor DC-SIGN discriminates among species and life cycle forms of Leishmania.

    PubMed

    Colmenares, María; Corbí, Angel L; Turco, Salvatore J; Rivas, Luis

    2004-01-15

    Infection of dendritic cells by the human protozoal parasite Leishmania is part of its survival strategy. The dendritic cell receptors for Leishmania have not been established and might differ in their interactions among Leishmania species and infective stages. We present evidence that the surface C-type lectin DC-SIGN (CD 209) is a receptor for promastigote and amastigote infective stages from both visceral (Leishmania infantum) and New World cutaneous (Leishmania pifanoi) Leishmania species, but not for Leishmania major metacyclic promastigotes, an Old World species causing cutaneous leishmaniasis. Leishmania binding to DC-SIGN was found to be independent of lipophosphoglycan, the major glycoconjugate of the promastigote plasma membrane. Our findings emphasize the relevance of DC-SIGN in Leishmania-dendritic cell interactions, an essential link between innate and Leishmania-specific adaptive immune responses, and suggest that DC-SIGN might be a therapeutic target for both visceral and cutaneous leishmaniasis

  11. IL-27 improves migrational and antiviral potential of CB dendritic cells.

    PubMed

    Birkholz, Julia; Doganci, Aysefa; Darstein, Claudia; Gehring, Stephan; Zepp, Fred; Meyer, Claudius U

    2014-06-01

    Interleukin (IL)-27 is known to be increased considerably in cord blood (CB) dendritic cells (DCs) after TLR ligation. Previously, we demonstrated that also basal IL-27 levels are higher in CB DCs. Here, we examined effects of IL-27 on monocyte derived dendritic cells (moDCs) to approach its particular role in the specialized immune system of the human neonate. Exogenous IL-27 promotes IL-27 transcription in CB and adult blood (AB) moDCs. IL-27 acts on CB moDCs primarily by significantly augmenting IL-27 protein, secondarily by increasing transcription of CXCL10 among other chemokines, chemokine receptor CCR1, interferon stimulated genes, transcription factor IRF8 and genes involved in antigen presentation. Furthermore, CB moDCs respond to IL-27 with augmented IL-8 and Tumor necrosis factor (TNF)-α. The results suggest that IL-27 enhances migrational and antiviral properties of CB dendritic cells.

  12. The transcription factor Fli-1 regulates monocyte, macrophage and dendritic cell development in mice.

    PubMed

    Suzuki, Eiji; Williams, Sarah; Sato, Shuzo; Gilkeson, Gary; Watson, Dennis K; Zhang, Xian K

    2013-07-01

    Fli-1 belongs to the Ets transcription factor family and is expressed in haematopoietic cells, including most of the cells that are active in immunity. The mononuclear phagocytes, i.e. monocytes, macrophages and dendritic cells, originate in haematopoietic stem cells and play an important role in immunity. To assess the role of Fli-1 in mononuclear phagocyte development in vivo, we generated mice that express a truncated Fli-1 protein, lacking the C-terminal transcriptional activation domain (Fli-1(Δ) (CTA) ). Fli-1(Δ) (CTA) (/Δ) (CTA) mice had significantly increased populations of haematopoietic stem cells and common dendritic cell precursors in bone marrow compared with wild-type littermates. Significantly increased classical dendritic cells, plasmacytoid dendritic cells, and macrophage populations were found in spleens from Fli-1(∆) (CTA) (/∆) (CTA) mice compared with wild-type littermates. Fli-1(Δ) (CTA) (/Δ) (CTA) mice also had increased pre-classical dendritic cell and monocyte populations in peripheral blood mononuclear cells. Furthermore, bone marrow reconstitution studies demonstrated that expression of Fli-1 in both haematopoietic cells and stromal cells affected mononuclear phagocyte development in mice. Expression of Fms-like tyrosine kinase 3 ligand (Flt3L), a haematopoietic growth factor, in multipotent progenitors was statistically significantly increased from Fli-1(∆) (CTA) (/∆) (CTA) mice compared with wild-type littermates. Fli-1 protein binds directly to the promoter region of the Flt3L gene. Hence, Fli-1 plays an important role in the mononuclear phagocyte development, and the C-terminal transcriptional activation domain of Fli-1 negatively modulates mononuclear phagocyte development.

  13. Phenotypic, ultra-structural and functional characterization of bovine peripheral blood dendritic cell subsets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dendritic cells (DC) are multifunctional cells that bridge the gap between innate and adaptive immune systems. In bovine, significant information is lacking on the precise identity and role of peripheral blood DC subsets. In this study, we identify and characterize bovine peripheral blood DC subsets...

  14. The thyroid hormone triiodothyronine reinvigorates dendritic cells and potentiates anti-tumor immunity.

    PubMed

    Alamino, V A; Montesinos, M M; Rabinovich, G A; Pellizas, C G

    Dendritic cell (DC) cancer vaccines have shown limited clinical benefit. Thus, the identification of signals and molecular pathways that potentiate the immunogenicity of DCs has become a major challenge in cancer research. Our studies demonstrate that triiodothyronine endows DCs with enhanced ability to stimulate cytotoxic T-cell responses with implications in DC-based immunotherapy.

  15. The thyroid hormone triiodothyronine reinvigorates dendritic cells and potentiates anti-tumor immunity

    PubMed Central

    Alamino, V.A.; Montesinos, M.M.; Rabinovich, G.A.; Pellizas, C.G.

    2016-01-01

    ABSTRACT Dendritic cell (DC) cancer vaccines have shown limited clinical benefit. Thus, the identification of signals and molecular pathways that potentiate the immunogenicity of DCs has become a major challenge in cancer research. Our studies demonstrate that triiodothyronine endows DCs with enhanced ability to stimulate cytotoxic T-cell responses with implications in DC-based immunotherapy. PMID:26942081

  16. Another armament in gut immunity: lymphotoxin-mediated crosstalk between innate lymphoid and dendritic cells.

    PubMed

    Spits, H

    2011-07-21

    Innate lymphoid cells (ILCs) are novel players in innate immunity. Tumanov et al. (Tumanov et al., 2011) demonstrate that crosstalk between ILCs and dendritic cells involving membrane-bound lymphotoxin in ILCs and its receptor is critical for protection against colitogenic bacteria.

  17. Rat bone marrow-derived dendritic cells generated with GM-CSF/IL-4 or FLT3L exhibit distinct phenotypical and functional characteristics.

    PubMed

    N'diaye, Marie; Warnecke, Andreas; Flytzani, Sevasti; Abdelmagid, Nada; Ruhrmann, Sabrina; Olsson, Tomas; Jagodic, Maja; Harris, Robert A; Guerreiro-Cacais, Andre Ortlieb

    2016-03-01

    Dendritic cells are professional APCs that play a central role in the initiation of immune responses. The limited ex vivo availability of dendritic cells inspires the widespread use of bone marrow-derived dendritic cells as an alternative in research. However, the functional characteristics of bone marrow-derived dendritic cells are incompletely understood. Therefore, we compared functional and phenotypic characteristics of rat bone marrow-derived dendritic cells generated with GM-CSF/IL-4 or FLT3 ligand bone marrow-derived dendritic cells. A comparison of surface markers revealed that FLT3 ligand-bone marrow-derived dendritic cells expressed signal regulatory protein α, CD103, and CD4 and baseline levels of MHC class II, CD40, and CD86, which were highly up-regulated upon stimulation. Conversely, GM-CSF/IL-4-bone marrow-derived dendritic cells constitutively expressed signal regulatory protein α, CD11c, and CD11b but only mildly up-regulated MHC class II, CD40, or CD86 following stimulation. Expression of dendritic cell-associated core transcripts was restricted to FLT3 ligand-bone marrow-derived dendritic cells . GM-CSF/IL-4-bone marrow-derived dendritic cells were superior at phagocytosis but were outperformed by FLT3 ligand-bone marrow-derived dendritic cells at antigen presentation and T cell stimulation in vitro. Stimulated GM-CSF/IL-4-bone marrow-derived dendritic cells secreted more TNF, CCL5, CCL20, and NO, whereas FLT3 ligand-bone marrow-derived dendritic cells secreted more IL-6 and IL-12. Finally, whereas GM-CSF/IL-4-bone marrow-derived dendritic cell culture supernatants added to resting T cell cultures promoted forkhead box p3(+) regulatory T cell populations, FLT3 ligand-bone marrow-derived dendritic cell culture supernatants drove Th17 differentiation. We conclude that rat GM-CSF/IL-4-bone marrow-derived dendritic cells and FLT3 ligand-bone marrow-derived dendritic cells are functionally distinct. Our data support the current rationale that FLT3

  18. Modulation of Dendritic Cell Immunobiology via Inhibition of 3-Hydroxy-3-Methylglutaryl-CoA (HMG-CoA) Reductase

    PubMed Central

    Luessi, Felix; Bendix, Ivo; Paterka, Magdalena; Prozorovski, Timour; Treue, Denise; Luenstedt, Sarah; Herz, Josephine; Siffrin, Volker; Infante-Duarte, Carmen; Zipp, Frauke; Waiczies, Sonia

    2014-01-01

    The maturation status of dendritic cells determines whether interacting T cells are activated or if they become tolerant. Previously we could induce T cell tolerance by applying a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor (HMGCRI) atorvastatin, which also modulates MHC class II expression and has therapeutic potential in autoimmune disease. Here, we aimed at elucidating the impact of this therapeutic strategy on T cell differentiation as a consequence of alterations in dendritic cell function. We investigated the effect of HMGCRI during differentiation of peripheral human monocytes and murine bone marrow precursors to immature DC in vitro and assessed their phenotype. To examine the stimulatory and tolerogenic capacity of these modulated immature dendritic cells, we measured proliferation and suppressive function of CD4+ T cells after stimulation with the modulated immature dendritic cells. We found that an HMGCRI, atorvastatin, prevents dendrite formation during the generation of immature dendritic cells. The modulated immature dendritic cells had a diminished capacity to take up and present antigen as well as to induce an immune response. Of note, the consequence was an increased capacity to differentiate naïve T cells towards a suppressor phenotype that is less sensitive to proinflammatory stimuli and can effectively inhibit the proliferation of T effector cells in vitro. Thus, manipulation of antigen-presenting cells by HMGCRI contributes to an attenuated immune response as shown by promotion of T cells with suppressive capacities. PMID:25013913

  19. Human Dendritic Cells Mitigate NK-Cell Dysfunction Mediated by Nonselective JAK1/2 Blockade.

    PubMed

    Curran, Shane A; Shyer, Justin A; St Angelo, Erin T; Talbot, Lillian R; Sharma, Sneh; Chung, David J; Heller, Glenn; Hsu, Katharine C; Betts, Brian C; Young, James W

    2017-01-01

    Janus kinase (JAK) inhibitors have achieved positive responses in myeloproliferative neoplasms, but at the expense of decreased natural killer (NK) cell numbers and compromised function. Selective JAK2 inhibition may also have a role in preventing and treating graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. Although JAK inhibitors can impair monocyte-derived dendritic cell (moDC) activation and function and suppress effector T-cell responses, the effects on NK cells and the relevant mechanisms remain undefined. Using common γc cytokines and distinct human dendritic cell (DC) subtypes, we compared the effects of a JAK2-specific (TG101348) with a less selective JAK1/2 (ruxolitinib) inhibitor on NK-cell activation and function. Ruxolitinib treatment completely blocked IL2, IL15, and DC-mediated STAT5 phosphorylation, along with the capacity of NK cells to secrete IFNγ or lyse NK cell-sensitive targets. Only NK-cell proliferation stimulated by moDCs resisted ruxolitinib treatment. In contrast, TG101348 treatment of stimulated NK cells resulted in far less functional compromise. TG101348 completely inhibited only soluble IL15-mediated STAT5 phosphorylation, which Langerhans-type DCs (LCs), presenting membrane-bound IL15 in trans, could salvage. These results demonstrate that ruxolitinib's nonselective inhibition of JAK1/2 results in profound NK-cell dysfunction by blocking downstream pSTAT5, hence providing a persuasive rationale for the development of selective JAK2 inhibitors for immunotherapeutic applications. Cancer Immunol Res; 5(1); 52-60. ©2016 AACR.

  20. Using Magnetic Resonance Imaging to Evaluate Dendritic Cell-Based Vaccination

    PubMed Central

    Ferguson, Peter M.; Slocombe, Angela; Tilley, Richard D.; Hermans, Ian F.

    2013-01-01

    Cancer immunotherapy with antigen-loaded dendritic cell-based vaccines can induce clinical responses in some patients, but further optimization is required to unlock the full potential of this strategy in the clinic. Optimization is dependent on being able to monitor the cellular events that take place once the dendritic cells have been injected in vivo, and to establish whether antigen-specific immune responses to the tumour have been induced. Here we describe the use of magnetic resonance imaging (MRI) as a simple, non-invasive approach to evaluate vaccine success. By loading the dendritic cells with highly magnetic iron nanoparticles it is possible to assess whether the injected cells drain to the lymph nodes. It is also possible to establish whether an antigen-specific response is initiated by assessing migration of successive rounds of antigen-loaded dendritic cells; in the face of a successfully primed cytotoxic response, the bulk of antigen-loaded cells are eradicated on-route to the node, whereas cells without antigen can reach the node unchecked. It is also possible to verify the induction of a vaccine-induced response by simply monitoring increases in draining lymph node size as a consequence of vaccine-induced lymphocyte trapping, which is an antigen-specific response that becomes more pronounced with repeated vaccination. Overall, these MRI techniques can provide useful early feedback on vaccination strategies, and could also be used in decision making to select responders from non-responders early in therapy. PMID:23734246

  1. Activation and genetic modification of human monocyte-derived dendritic cells using attenuated Salmonella typhimurium.

    PubMed

    Michael, Agnieszka; John, Justin; Meyer, Brendan; Pandha, Hardev

    2010-03-05

    Live attenuated bacterial vectors, such as Salmonella typhimurium, have shown promise as delivery vehicles for DNA. We have examined two new strains of S. typhimurium and their impact on dendritic cell maturation (CD12-sifA/aroC mutant and WT05-ssaV/aroC, both in TML background). Strain WT05 matured dendritic cells in a more efficient way; caused higher release of cytokines TNF-alpha, IL-12, IL-1beta; and was efficient for gene transfer. These findings suggest that the genetic background of the attenuation can influence the pattern of inflammatory immune response to Salmonella infection.

  2. Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

    DTIC Science & Technology

    2012-07-01

    Mediated by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy PRINCIPAL INVESTIGATOR: David J. Chung, M D , Ph D...CONTRACT NUMBER Evaluation of Immune Responses Mediated by Listeria -Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy 5b...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The purpose of this project is to study the immunomodulatory effect of Listeria on

  3. Dendritic Cell Targeting of Bacillus anthracis Protective Antigen Expressed by Lactobacillus acidophilus Protects Mice from Lethal Challenge

    DTIC Science & Technology

    2008-10-28

    Dendritic cell targeting of Bacillus anthracis protective antigen expressed by Lactobacillus acidophilus protects mice from lethal challenge M...lethal chal- lenge. A vaccine strategy was established by using Lactobacillus acidophilus to deliver Bacillus anthracis protective antigen (PA) via...4. TITLE AND SUBTITLE Dendritic cell targeting of Bacillus anthracis protective antigen expressed by Lactobacillus acidophilus protects mice

  4. Calcitonin gene-related peptide (CGRP) stimulates purkinje cell dendrite growth in culture.

    PubMed

    D'Antoni, Simona; Zambusi, Laura; Codazzi, Franca; Zacchetti, Daniele; Grohovaz, Fabio; Provini, Luciano; Catania, Maria Vincenza; Morara, Stefano

    2010-12-01

    Previous reports described the transient expression during development of Calcitonin Gene-Related Peptide (CGRP) in rodent cerebellar climbing fibers and CGRP receptor in astrocytes. Here, mixed cerebellar cultures were used to analyze the effects of CGRP on Purkinje cells growth. Our results show that CGRP stimulated Purkinje cell dendrite growth under cell culture conditions mimicking Purkinje cell development in vivo. The stimulation was not blocked by CGRP8-37, a specific antagonist, suggesting the activation of other related receptors. CGRP did not affect survival of Purkinje cells, granule cells or astrocytes. The selective expression of Receptor Component Protein (RCP) (a component of CGRP receptor family) in astrocytes points to a role of these cells as mediators of CGRP effect. Finally, in pure cerebellar astrocyte cultures CGRP induced a transient morphological differentiation from flat, polygonal to stellate form. It is concluded that CGRP influences Purkinje cell dendrite growth in vitro, most likely through the involvement of astrocytes.

  5. Intestinal dendritic cells change in number in fulminant hepatic failure

    PubMed Central

    Cao, Xu; Liu, Mei; Wang, Peng; Liu, Dong-Yan

    2015-01-01

    AIM: To investigate the change in intestinal dendritic cell (DC) number in fulminant hepatic failure (FHF). METHODS: An animal model of FHF was created. Intestinal CD11b/c was detected by immunohistochemistry and Western blot. Quantitative real-time polymerase chain reaction (PCR) was used to detect intestinal integrin-α mRNA expression. Intestinal CD83, CD86, CD74, CD3 and AKT were detected by immunohistochemistry, Western blot and PCR. Phosphorylated-AKT (p-AKT) was detected by immunohistochemistry and Western blot. RESULTS: In the FHF group [D-galactosamine (D-Galn) + lipopolysaccharide (LPS) group], the mice began to die after 6 h; conversely, in the D-Galn and LPS groups, the activity of mice was poor, but there were no deaths. Immunohistochemistry results showed that in FHF, the expression of CD11b/c (7988400 ± 385941 vs 1102400 ± 132273, P < 0.05), CD83 (13875000 ± 467493 vs 9257600 ± 400364, P < 0.05), CD86 (7988400 ± 385941 vs 1102400 ± 13227, P < 0.05) and CD74 (11056000 ± 431427 vs 4633400 ± 267903, P < 0.05) was significantly increased compared with the normal saline (NS) group. Compared with the NS group, the protein expression of CD11b/c (5.4817 ± 0.77 vs 1.4073 ± 0.37, P < 0.05) and CD86 (4.2673 ± 0.69 vs 1.1379 ± 0.42, P < 0.05) was significantly increased. Itg-α (1.1224 ± 0.3 vs 0.4907 ± 0.19, P < 0.05), CD83 (3.6986 ± 0.40 vs 1.0762 ± 0.22, P < 0.05) and CD86 (1.5801 ± 0.32 vs 0.8846 ± 0.10, P < 0.05) mRNA expression was increased significantly in the FHF group. At the protein level, expression of CD74 in the FHF group (2.3513 ± 0.52) was significantly increased compared with the NS group (1.1298 ± 0.33), whereas in the LPS group (2.3891 ± 0.47), the level of CD74 was the highest (P < 0.05). At the gene level, the relative expression of CD74 mRNA in the FHF group (1.5383 ± 0.26) was also significantly increased in comparison to the NS group (0.7648 ± 0.22; P < 0.05). CD3 expression was the highest in the FHF group (P < 0

  6. 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.

  7. iPS-cell derived dendritic cells and macrophages for cancer therapy.

    PubMed

    Senju, Satoru

    2016-08-01

    Antibody-based anti-cancer immunotherapy was recently recognized as one of the truly effective therapies for cancer patients. Antibodies against cell surface cancer antigens, such as CD20, and also those against immune-inhibitory molecules called "immune checkpoint blockers", such as CTLA4 or PD1, have emerged. Large-scale clinical trials have confirmed that, in some cases, antibody-based drugs are superior to conventional chemotherapeutic agents. These antibody-based drugs are now being manufactured employing a mass-production system by pharmaceutical companies. Anti-cancer therapy by immune cells, i.e. cell-based immunotherapy, is expected to be more effective than antibody therapy, because immune cells can recognize, infiltrate, and act in cancer tissues more directly than antibodies. In order to achieve cell-based anti-cancer immunotherapy, it is necessary to develop manufacturing systems for mass-production of immune cells. Our group has been studying immunotherapy with myeloid cells derived from ES cells or iPS cells. These pluripotent stem cells can be readily propagated under constant culture conditions, with expansion into a large quantity. We consider these stem cells to be the most suitable cellular source for mass-production of immune cells. This review introduces our studies on anti-cancer therapy with iPS cell-derived dendritic cells and iPS cell-derived macrophages.

  8. Evaluation In Vitro of Immunoregulatory Cytokines Secretion by Dendritic Cells in Mountain Skiers.

    PubMed

    Evstratova, V S; Nikityuk, D B; Riger, N A; Fedyanina, N V; Khanferyan, R A

    2016-11-01

    In vitro production of immunoregulatory cytokines (IFN-α, IL-31, TNF-β, IL-17A, IL-7, IL-1RA, IL-1α, IL-10, IL-15, IL-21, IL-22, IL-23, IL-27, and IL-9) by dendritic cell cultures was compared in ski athletes and healthy donors. Effect of prolonged intense physical exercise on secretory activity of immune cells was investigated. In both groups, secretion of IL-1RA, IL-10, IL-1α by dendritic cells was revealed, but there were significant differences in IL-1RA, IL-1α content (p<0.05) with lower level in the group of athletes. Production of IL-17A and IL-7 by dendritic cells in the group of athletes was not detected. In athletes, several proinflammatory cytokines (IFN-α, IL-31, and TNF-β) were secreted by cells in high concentrations, in contrast to the control group. In both groups, dendritic cells did not secrete IL-15, IL-21, IL-22, IL-23, IL-27, and IL-9.

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

    PubMed Central

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

    1997-01-01

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

  10. BDNF over-expression increases olfactory bulb granule cell dendritic spine density in vivo.

    PubMed

    McDole, B; Isgor, C; Pare, C; Guthrie, K

    2015-09-24

    Olfactory bulb granule cells (GCs) are axon-less, inhibitory interneurons that regulate the activity of the excitatory output neurons, the mitral and tufted cells, through reciprocal dendrodendritic synapses located on GC spines. These contacts are established in the distal apical dendritic compartment, while GC basal dendrites and more proximal apical segments bear spines that receive glutamatergic inputs from the olfactory cortices. This synaptic connectivity is vital to olfactory circuit function and is remodeled during development, and in response to changes in sensory activity and lifelong GC neurogenesis. Manipulations that alter levels of the neurotrophin brain-derived neurotrophic factor (BDNF) in vivo have significant effects on dendritic spine morphology, maintenance and activity-dependent plasticity for a variety of CNS neurons, yet little is known regarding BDNF effects on bulb GC spine maturation or maintenance. Here we show that, in vivo, sustained bulbar over-expression of BDNF in transgenic mice produces a marked increase in GC spine density that includes an increase in mature spines on their apical dendrites. Morphometric analysis demonstrated that changes in spine density were most notable in the distal and proximal apical domains, indicating that multiple excitatory inputs are potentially modified by BDNF. Our results indicate that increased levels of endogenous BDNF can promote the maturation and/or maintenance of dendritic spines on GCs, suggesting a role for this factor in modulating GC functional connectivity within adult olfactory circuitry.

  11. Dendritic cells drive memory CD8 T-cell homeostasis via IL-15 transpresentation

    PubMed Central

    Stonier, Spencer W.; Ma, Lisa J.; Castillo, Eliseo F.

    2008-01-01

    Interleukin-15 (IL-15) is crucial for the development of naive and memory CD8 T cells and is delivered through a mechanism called transpresentation. Previous studies showed that memory CD8 T cells require IL-15 transpresentation by an as yet unknown cell of hematopoietic origin. We hypothesized that dendritic cells (DCs) transpresent IL-15 to CD8 T cells, and we examined this by developing a transgenic model that limits IL-15 transpresentation to DCs. In this study, IL-15 transpresentation by DCs had little effect on restoring naive CD8 T cells but contributed to the development of memory-phenotype CD8 T cells. The generation of virus-specific, memory CD8 T cells was partially supported by IL-15Rα+ DCs through the preferential enhancement of a subset of KLRG-1+CD27− CD8 T cells. In contrast, these DCs were largely sufficient in driving normal homeostatic proliferation of established memory CD8 T cells, suggesting that memory CD8 T cells grow more dependent on IL-15 transpresentation by DCs. Overall, our study clearly supports a role for DCs in memory CD8 T-cell homeostasis but also provides evidence that other hematopoietic cells are involved in this function. The identification of DCs fulfilling this role will enable future studies to better focus on mechanisms regulating T-cell homeostasis. PMID:18812469

  12. Dendritic cells drive memory CD8 T-cell homeostasis via IL-15 transpresentation.

    PubMed

    Stonier, Spencer W; Ma, Lisa J; Castillo, Eliseo F; Schluns, Kimberly S

    2008-12-01

    Interleukin-15 (IL-15) is crucial for the development of naive and memory CD8 T cells and is delivered through a mechanism called transpresentation. Previous studies showed that memory CD8 T cells require IL-15 transpresentation by an as yet unknown cell of hematopoietic origin. We hypothesized that dendritic cells (DCs) transpresent IL-15 to CD8 T cells, and we examined this by developing a transgenic model that limits IL-15 transpresentation to DCs. In this study, IL-15 transpresentation by DCs had little effect on restoring naive CD8 T cells but contributed to the development of memory-phenotype CD8 T cells. The generation of virus-specific, memory CD8 T cells was partially supported by IL-15Ralpha(+) DCs through the preferential enhancement of a subset of KLRG-1(+)CD27(-) CD8 T cells. In contrast, these DCs were largely sufficient in driving normal homeostatic proliferation of established memory CD8 T cells, suggesting that memory CD8 T cells grow more dependent on IL-15 transpresentation by DCs. Overall, our study clearly supports a role for DCs in memory CD8 T-cell homeostasis but also provides evidence that other hematopoietic cells are involved in this function. The identification of DCs fulfilling this role will enable future studies to better focus on mechanisms regulating T-cell homeostasis.

  13. Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells

    SciTech Connect

    Kunzmann, Andrea; Andersson, Britta; Vogt, Carmen; Feliu, Neus; Ye Fei; Gabrielsson, Susanne; Toprak, Muhammet S.; Buerki-Thurnherr, Tina; Laurent, Sophie; Vahter, Marie; Krug, Harald; Muhammed, Mamoun; Scheynius, Annika; Fadeel, Bengt

    2011-06-01

    Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to 'smart' drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion. On the other hand, labeling of immune cells serves as an ideal tool for visualization, diagnosis or treatment of inflammatory processes, which requires the efficient internalization of the nanoparticles into the cells of interest. Here, we compare novel monodispersed silica-coated iron oxide nanoparticles with commercially available dextran-coated iron oxide nanoparticles. The silica-coated iron oxide nanoparticles displayed excellent magnetic properties. Furthermore, they were non-toxic to primary human monocyte-derived macrophages at all doses tested whereas dose-dependent toxicity of the smaller silica-coated nanoparticles (30 nm and 50 nm) was observed for primary monocyte-derived dendritic cells, but not for the similarly small dextran-coated iron oxide nanoparticles. No macrophage or dendritic cell secretion of pro-inflammatory cytokines was observed upon administration of nanoparticles. The silica-coated iron oxide nanoparticles were taken up to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. Cellular internalization of the silica-coated nanoparticles was through an active, actin cytoskeleton-dependent process. We conclude that these novel silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications.

  14. EBI2 augments Tfh cell fate by promoting interaction with IL2-quenching dendritic cells

    PubMed Central

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

    2016-01-01

    T follicular helper (Tfh) cells are a CD4 T cell subset that is important for supporting plasma cell and germinal center (GC) responses1,2. The initial induction of Tfh cell properties occurs within the first few days following activation by antigen recognition on dendritic cells (DCs), though how DCs promote this cell-fate decision is not fully understood1,2. Moreover, although Tfh cells are uniquely defined by expression of the follicle-homing receptor CXCR51,2, the guidance receptor promoting the earlier localization of activated T cells at the B cell follicle–T zone interface has been unclear3–5. Here we show that the G-protein coupled receptor EBI2 (GPR183) and its ligand 7α,25-dihydroxycholesterol (7α,25-OHC) mediate positioning of activated CD4 T cells at the follicle–T zone interface. In this location they interact with activated DCs and are exposed to Tfh cell-promoting ICOS ligand. IL2 is a cytokine that has multiple influences on T cell fate, including negative regulation of Tfh cell differentiation6–10. We demonstrate that activated DCs in the outer T zone further augment Tfh cell differentiation by producing membrane and soluble forms of CD25, the IL2 receptor α chain, and quenching T cell-derived IL2. Mice lacking EBI2 in T cells or CD25 in DCs have reduced Tfh cells and mount defective T cell-dependent plasma cell and GC responses. These findings demonstrate that distinct niches within the lymphoid organ T zone support distinct cell fate decisions, and they establish a function for DC-derived CD25 in controlling IL2 availability and T cell differentiation. PMID:27147029

  15. Critical role of dendritic cells in T cell retention in the interfollicular region of Peyer's patches.

    PubMed

    Obata, Takashi; Shibata, Naoko; Goto, Yoshiyuki; Ishikawa, Izumi; Sato, Shintaro; Kunisawa, Jun; Kiyono, Hiroshi

    2013-07-15

    Peyer's patches (PPs) simultaneously initiate active and quiescent immune responses in the gut. The immunological function is achieved by the rigid regulation of cell distribution and trafficking, but how the cell distribution is maintained remains to be elucidated. In this study, we show that binding of stromal cell-derived lymphoid chemokines to conventional dendritic cells (cDCs) is essential for the retention of naive CD4(+) T cells in the interfollicular region (IFR) of PPs. Transitory depletion of CD11c(high) cDCs in mice rapidly impaired the IFR structure in the PPs without affecting B cell follicles or germinal centers, lymphoid chemokine production from stromal cells, or the immigration of naive T cells into the IFRs of PPs. The cDC-orchestrated retention of naive T cells was mediated by heparinase-sensitive molecules that were expressed on cDCs and bound the lymphoid chemokine CCL21 produced from stromal cells. These data collectively reveal that interactions among cDCs, stromal cells, and naive T cells are necessary for the formation of IFRs in the PPs.

  16. 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.

  17. Antigen persistence is required for dendritic cell licensing and CD8+ T cell cross-priming.

    PubMed

    Jusforgues-Saklani, Hélène; Uhl, Martin; Blachère, Nathalie; Lemaître, Fabrice; Lantz, Olivier; Bousso, Philippe; Braun, Deborah; Moon, James J; Albert, Matthew L

    2008-09-01

    It has been demonstrated that CD4(+) T cells require Ag persistence to achieve effective priming, whereas CD8(+) T cells are on "autopilot" after only a brief exposure. This finding presents a disturbing conundrum as it does not account for situations in which CD8(+) T cells require CD4(+) T cell help. We used a physiologic in vivo model to study the requirement of Ag persistence for the cross-priming of minor histocompatibility Ag-specific CD8(+) T cells. We report inefficient cross-priming in situations in which male cells are rapidly cleared. Strikingly, the failure to achieve robust CD8(+) T cell activation is not due to a problem with cross-presentation. In fact, by providing "extra help" in the form of dendritic cells (DCs) loaded with MHC class II peptide, it was possible to achieve robust activation of CD8(+) T cells. Our data suggest that the "licensing" of cross-presenting DCs does not occur during their initial encounter with CD4(+) T cells, thus accounting for the requirement for Ag persistence and suggesting that DCs make multiple interactions with CD8(+) T cells during the priming phase. These findings imply that long-lived Ag is critical for efficient vaccination protocols in which the CD8(+) T cell response is helper-dependent.

  18. The SNARE VAMP7 Regulates Exocytic Trafficking of Interleukin-12 in Dendritic Cells

    PubMed Central

    Chiaruttini, Giulia; Piperno, Giulia M.; Jouve, Mabel; De Nardi, Francesca; Larghi, Paola; Peden, Andrew A.; Baj, Gabriele; Müller, Sabina; Valitutti, Salvatore; Galli, Thierry; Benvenuti, Federica

    2016-01-01

    Summary Interleukin-12 (IL-12), produced by dendritic cells in response to activation, is central to pathogen eradication and tumor rejection. The trafficking pathways controlling spatial distribution and intracellular transport of IL-12 vesicles to the cell surface are still unknown. Here, we show that intracellular IL-12 localizes in late endocytic vesicles marked by the SNARE VAMP7. Dendritic cells (DCs) from VAMP7-deficient mice are partially impaired in the multidirectional release of IL-12. Upon encounter with antigen-specific T cells, IL-12-containing vesicles rapidly redistribute at the immune synapse and release IL-12 in a process entirely dependent on VAMP7 expression. Consistently, acquisition of effector functions is reduced in T cells stimulated by VAMP7-null DCs. These results provide insights into IL-12 intracellular trafficking pathways and show that VAMP7-mediated release of IL-12 at the immune synapse is a mechanism to transmit innate signals to T cells. PMID:26972013

  19. 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

  20. 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.

  1. Human dendritic cells and macrophages. In situ immunophenotypic definition of subsets that exhibit specific morphologic and microenvironmental characteristics.

    PubMed Central

    Wood, G. S.; Turner, R. R.; Shiurba, R. A.; Eng, L.; Warnke, R. A.

    1985-01-01

    Using a panel of monoclonal antibodies and antisera in situ, the authors have defined subsets of human dendritic cells and macrophages that exhibit specific morphologic and microenvironmental characteristics. All subsets contained cells that reacted with antibodies directed against HLA-A,B,C, HLA-Dr, leukocyte common, Leu-M3, and Leu-3(T4) antigens. R4/23 and anti-S100 defined three major subsets. R4/23+, S100- cells constituted the B-cell-related follicular dendritic cells, which were identified only within the germinal center/mantle microenvironment of lymphoid follicles. R4/23-, S100+ cells constituted the T-cell-related dendritic cell subset. Anti-Leu-6(T6) further subdivided this group into Leu-6(T6)- interdigitating cells within the T-cell microenvironments of lymphoid organs and Leu-6(T6)+ Langerhans cells found predominantly in epithelial microenvironments, especially the skin. R4/23-, S100- cells constituted the nondendritic tissue macrophage subset which was widely distributed, primarily outside of dendritic-cell microenvironments. These data indicate that although dendritic cells and macrophages share several common antigenic features, morphologically and microenvironmentally distinct subsets express distinct immunologic phenotypes. Such data may provide insight into the ontogeny and function of these subsets and constitute a basis for the comparison of normal dendritic cells and macrophages to various histiocytic proliferative disorders. Images Figure 1 Figure 2 p78-c Figure 3 Figure 4 Figure 5 PMID:3985124

  2. CD44: a novel synaptic cell adhesion molecule regulating structural and functional plasticity of dendritic spines

    PubMed Central

    Roszkowska, Matylda; Skupien, Anna; Wójtowicz, Tomasz; Konopka, Anna; Gorlewicz, Adam; Kisiel, Magdalena; Bekisz, Marek; Ruszczycki, Blazej; Dolezyczek, Hubert; Rejmak, Emilia; Knapska, Ewelina; Mozrzymas, Jerzy W.; Wlodarczyk, Jakub; Wilczynski, Grzegorz M.; Dzwonek, Joanna

    2016-01-01

    Synaptic cell adhesion molecules regulate signal transduction, synaptic function, and plasticity. However, their role in neuronal interactions with the extracellular matrix (ECM) is not well understood. Here we report that the CD44, a transmembrane receptor for hyaluronan, modulates synaptic plasticity. High-resolution ultrastructural analysis showed that CD44 was localized at mature synapses in the adult brain. The reduced expression of CD44 affected the synaptic excitatory transmission of primary hippocampal neurons, simultaneously modifying dendritic spine shape. The frequency of miniature excitatory postsynaptic currents decreased, accompanied by dendritic spine elongation and thinning. These structural and functional alterations went along with a decrease in the number of presynaptic Bassoon puncta, together with a reduction of PSD-95 levels at dendritic spines, suggesting a reduced number of functional synapses. Lack of CD44 also abrogated spine head enlargement upon neuronal stimulation. Moreover, our results indicate that CD44 contributes to proper dendritic spine shape and function by modulating the activity of actin cytoskeleton regulators, that is, Rho GTPases (RhoA, Rac1, and Cdc42). Thus CD44 appears to be a novel molecular player regulating functional and structural plasticity of dendritic spines. PMID:27798233

  3. 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).

  4. Melanopsin ganglion cells extend dendrites into the outer retina during early postnatal development.

    PubMed

    Renna, Jordan M; Chellappa, Deepa K; Ross, Christopher L; Stabio, Maureen E; Berson, David M

    2015-09-01

    Melanopsin ganglion cells express the photopigment melanopsin and are the first functional photoreceptors to develop in the mammalian retina. They have been shown to play a variety of important roles in visual development and behavior in the early postnatal period (Johnson et al., 2010; Kirkby and Feller, 2013; Rao et al., 2013; Renna et al., 2011). Here, we probed the maturation of the dendritic arbors of melanopsin ganglion cells during this developmental period in mice. We found that some melanopsin ganglion cells (mainly the M1-subtype) transiently extend their dendrites not only into the inner plexiform layer (where they receive synaptic inputs from bipolar and amacrine cells) but also into the outer plexiform layer, where in mature retina, rod and cone photoreceptors are thought to contact only bipolar and horizontal cells. Thus, some immature melanopsin ganglion cells are biplexiform. This feature is much less common although still present in the mature retina. It reaches peak incidence 8-12 days after birth, before the eyes open and bipolar cells are sufficiently mature to link rods and cones to ganglion cells. At this age, some outer dendrites of melanopsin ganglion cells lie in close apposition to the axon terminals of cone photoreceptors and express a postsynaptic marker of glutamatergic transmission, postsynaptic density-95 protein (PSD-95). These findings raise the possibility of direct, monosynaptic connections between cones and melanopsin ganglion cells in the early postnatal retina. We provide a detailed description of the developmental profile of these processes and consider their possible functional and evolutionary significance.

  5. Dendritic cells and parasites: from recognition and activation to immune response instruction.

    PubMed

    Motran, Claudia Cristina; Ambrosio, Laura Fernanda; Volpini, Ximena; Celias, Daiana Pamela; Cervi, Laura

    2017-02-01

    The effective defense against parasite infections requires the ability to mount an appropriate and controlled specific immune response able to eradicate the invading pathogen while limiting the collateral damage to self-tissues. Dendritic cells are key elements for the development of immunity against parasites; they control the responses required to eliminate these pathogens while maintaining host homeostasis. Ligation of dendritic cell pattern recognition receptors by pathogen-associated molecular pattern present in the parasites initiates signaling pathways that lead to the production of surface and secreted proteins that are required, together with the antigen, to induce an appropriate and timely regulated immune response. There is evidence showing that parasites can influence and regulate dendritic cell functions in order to promote a more permissive environment for their survival. In this review, we will focus on new insights about the ability of protozoan and helminth parasites or their products to modify dendritic cell function and discuss how this interaction is crucial in shaping the host response.

  6. Dendritic Morphology of Caudal Periaqueductal Gray Projecting Retinal Ganglion Cells in Mongolian Gerbil (Meriones unguiculatus)

    PubMed Central

    Ren, Chaoran; Pu, Mingliang; Cui, Qi; So, Kwok-Fai

    2014-01-01

    In this study we investigated the morphological features of the caudal periaqueductal gray (cPAG)-projecting retinal ganglion cells (RGCs) in Mongolian gerbils using retrograde labeling, in vitro intracellular injection, confocal microscopy and three-dimensional reconstruction approaches. cPAG-projecting RGCs exhibit small somata (10–17 µm) and irregular dendritic fields (201–298 µm). Sizes of somata and dendritic fields do not show obvious variation at different distance from the optic disk (eccentricity). Dendrites are moderately branched. Morphological analysis (n = 23) reveals that cPAG-projecting RGCs ramified in sublamina a and b in the inner plexiform layer. These cells exhibit different stratification patterns based on the thickness of dendritic bands in sublaminas a and b: majority of analyzed cells (16 out of 23) have two bands of arborizations share similar thickness. The rest of analyzed cells (7 out of 23) exhibit thinner band in sublamina a than in sublamina b. Together, the present study suggests that cPAG of Mongolian gerbil could receive direct retinal inputs from two types of bistratified RGCs. Furthermore, a small subset of melanopsin-expressing RGCs (total 41 in 6 animals) is shown to innervate the rostral PAG (rPAG). Functional characteristics of these non-visual center projecting RGCs remain to be determined. PMID:25054882

  7. Assessing the roles of galectins in regulating dendritic cell migration through extracellular matrix and across lymphatic endothelial cells.

    PubMed

    Thiemann, Sandra; Man, Jeanette H; Baum, Linda G

    2015-01-01

    Leukocyte migration from the bloodstream into tissues, and from tissues to lymph nodes, depends on expression of specific adhesion and signaling molecules by vascular endothelial cells and lymphatic endothelial cells. Tissue damage and microbial infection induce vascular endothelial cells to up-regulate expression of adhesion molecules to facilitate entry of several leukocyte populations from blood into tissues. Many of these cells then leave inflamed tissue and migrate to regional lymph nodes. A critical population that emigrates from inflamed tissue is dendritic cells. Dendritic cells in tissue have to migrate through extracellular matrix and across a layer of lymphatic endothelial cells to enter the lymphatic vasculature. Little is known about the adhesion molecules expressed by lymphatic endothelial cells or the processes required for the critical step of dendritic cell exit from tissues, specifically migration through the extracellular matrix and basal-to-apical migration across the lymphatic endothelial cell layer into lymphatic vasculature.Members of the galectin family of carbohydrate binding proteins are expressed in both vascular and lymphatic endothelial cells. Dynamic changes in galectin expression during inflammation are known to regulate leukocyte tissue entry during inflammation. However, the roles of galectin family members expressed by lymphatic endothelial cells in leukocyte tissue exit remain to be explored.Here, we describe an in vitro transmigration assay that mimics dendritic cell tissue exit in the presence and absence of galectin protein. Fluorescently labeled human dendritic cell migration through extracellular matrix and across human lymphatic endothelial cells is examined in the presence and absence of recombinant human galectin protein.

  8. High frequency of clonal IG and T-cell receptor gene rearrangements in histiocytic and dendritic cell neoplasms

    PubMed Central

    Huang, Wenting; Qiu, Tian; Zeng, Linshu; Zheng, Bo; Ying, Jianming; Feng, Xiaoli

    2016-01-01

    The 2008 World Health Organization (WHO) diagnostic criteria of histiocytic and dendritic cell neoplasms from hematopoietic and lymphoid tissues no longer required the absence of clonal B-cell/T-cell receptor gene rearrangements. It is true that the clonal B-cell/T-cell receptor gene rearrangements have been identified in rare cases of histiocytic and dendritic cell neoplasms, such as those with or following lymphoma/leukemia or in some sporadic histiocytic/dendritic cell sarcomas, but the clonal features of such group of tumor are still not clear. Here we investigated the clonal status of 33 samples including Langerhans cell histiocytosis (LCH), Langerhans cell sarcoma (LCS), follicular dendritic cell sarcoma (FDCS), interdigitating dendritic cell sarcoma (IDCS) and histiocytic sarcoma (HS). Among them, twenty-eight cases were sporadic without current or past lymphoma/leukemia. Three cases were found with a past history of T-cell lymphoma, one case was followed by extraosseous plasmacytoma, and one case was found with diffuse large B-cell lymphoma (DLBCL). Our results showed that there was a high frequency of clonal IG and T-cell receptor gene rearrangements in these cases. Notably, 4 cases of LCH and 2 cases of FDCS showed both B and T cell receptor gene rearrangements concurrently. One case of FDCS synchronous with DLBCL showed identical clonal IGH in both tumor populations and clonal TCRβ in FDCS alone. No matter if the presence of clonal receptor gene rearrangements was associated with the tumor origin or tumorigenesis, it might serve as a novel tumor marker for developing target therapy. PMID:27823979

  9. Comparative analysis of signature genes in PRRSV-infected porcine monocyte-derived dendritic cells at differential activation statuses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Activation statuses of monocytic cells including monocytes, macrophages and dendritic cells (DCs) are critically important for antiviral immunity. In particular, some devastating viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), are capable of directly infecting these c...

  10. The CD8alpha(+) dendritic cell is responsible for inducing peripheral self-tolerance to tissue-associated antigens.

    PubMed

    Belz, Gabrielle T; Behrens, Georg M N; Smith, Chris M; Miller, Jacques F A P; Jones, Claerwen; Lejon, Kristina; Fathman, C Garrison; Mueller, Scott N; Shortman, Ken; Carbone, Francis R; Heath, William R

    2002-10-21

    We previously described a mechanism for the maintenance of peripheral self-tolerance. This involves the cross-presentation of tissue-associated antigens by a bone marrow-derived cell type that stimulates the proliferation and ultimate deletion of self-reactive CD8 T cells. This process has been referred to as cross-tolerance. Here, we characterize the elusive cell type responsible for inducing cross-tolerance as a CD8alpha(+) dendritic cell (DC). To achieve this aim, transgenic mice were generated expressing yellow fluorescent protein (YFP) linked to CTL epitopes for ovalbumin and glycoprotein B (gB) of herpes simplex virus under the rat insulin promoter (RIP). Although tracking of YFP was inconclusive, the use of a highly sensitive gB-specific hybridoma that produced beta-galactosidase on encounter with antigen, enabled detection of antigen presentation by cells isolated from the pancreatic lymph node. This showed that a CD11c(+)CD8alpha(+) cell was responsible for cross-tolerance, the same DC subset as previously implicated in cross-priming. These data indicate that CD8alpha(+) DCs play a critical role in both tolerance and immunity to cell-associated antigens, providing a potential mechanism by which cytotoxic T lymphocyte can be immunized to viral antigens while maintaining tolerance to self.

  11. Cytoplasmic delivery of siRNAs to monocytes and dendritic cells via electroporation.

    PubMed

    Sioud, Mouldy

    2015-01-01

    RNA interference has been of great interest not only as a research tool to suppress gene expression but also as an emerging therapeutic strategy to silence disease genes. However, the therapeutic use of siRNA faces the in vivo delivery challenge. An alternative method that could potentially be used for siRNA delivery into primary immune cells for therapeutic purposes is an ex vivo route, whereby immune cells could be isolated from a patient, reprogrammed with siRNAs, and infused back into the same patient. This chapter describes siRNA delivery into human primary monocytes and dendritic cells using a standard electroporation technique. Dendritic cells occupy a central role in the immune system, orchestrating a wide repertoire of responses that span from the development of self-tolerance to the generation of protective CD8+ T cell immunity.

  12. Physiological Role of Plasmacytoid Dendritic Cells and Their Potential Use in Cancer Immunity

    PubMed Central

    Schettini, Jorge; Mukherjee, Pinku

    2008-01-01

    Dendritic cells (DCs) play a pivotal role in the control of innate and adaptive immune responses. They are a heterogeneous cell population, where plasmacytoid dendritic cells (pDCs) are a unique subset capable of secreting high levels of type I IFNs. It has been demonstrated that pDCs can coordinate events during the course of viral infection, atopy, autoimmune diseases, and cancer. Therefore, pDC, as a main source of type I IFN, is an attractive target for therapeutic manipulations of the immune system to elicit a powerful immune response against tumor antigens in combination with other therapies. The therapeutic vaccination with antigen-pulsed DCs has shown a limited efficacy to generate an effective long-lasting immune response against tumor cells. A rational manipulation and design of vaccines which could include DC subsets outside “Langerhans cell paradigm” might allow us to improve the therapeutic approaches for cancer patients. PMID:19190769

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

    PubMed

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

    2004-03-15

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

  14. Antigen availability determines CD8+ T cell-dendritic cell interaction kinetics and memory fate decisions

    PubMed Central

    Henrickson, Sarah E.; Stutte, Susanne; Quigley, Michael; Alexe, Gabriela; Iannacone, Matteo; Flynn, Michael P.; Omid, Shaida; Jesneck, Jonathan L.; Imam, Sabrina; Mempel, Thorsten R.; Mazo, Irina B.; Haining, William N.; von Andrian, Ulrich H.

    2014-01-01

    Summary T cells are activated by antigen (Ag) bearing dendritic cells (DCs) in lymph nodes in 3 phases. The duration of the initial phase of transient, serial DC-T cell interactions is inversely correlated with Ag dose. The second phase, characterized by stable DC-T cell contacts, is believed to be necessary for full-fledged T cell activation. Here we have shown that this is not the case. CD8+ T cells interacting with DCs presenting low-dose, short-lived Ag did not transition to phase 2, while higher Ag dose yielded phase 2 transition. Both antigenic constellations promoted T cell proliferation and effector differentiation, but yielded different transcriptome signatures at 12h and 24h. T cells that experienced phase 2 developed long-lived memory, whereas conditions without stable contacts yielded immunological amnesia. Thus, T cells make fate decisions within hours after Ag exposure resulting in long-term memory or abortive effector responses, correlating with T cell-DCs interaction kinetics. PMID:24054328

  15. Plasmacytoid dendritic cells sense hepatitis C virus-infected cells, produce interferon, and inhibit infection.

    PubMed

    Takahashi, Ken; Asabe, Shinichi; Wieland, Stefan; Garaigorta, Urtzi; Gastaminza, Pablo; Isogawa, Masanori; Chisari, Francis V

    2010-04-20

    Hepatitis C virus (HCV), a member of the Flaviviridae family, is a single-stranded positive-sense RNA virus that infects >170 million people worldwide and causes acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Despite its ability to block the innate host response in infected hepatocyte cell lines in vitro, HCV induces a strong type 1 interferon (IFN) response in the infected liver. The source of IFN in vivo and how it is induced are currently undefined. Here we report that HCV-infected cells trigger a robust IFN response in plasmacytoid dendritic cells (pDCs) by a mechanism that requires active viral replication, direct cell-cell contact, and Toll-like receptor 7 signaling, and we show that the activated pDC supernatant inhibits HCV infection in an IFN receptor-dependent manner. Importantly, the same events are triggered by HCV subgenomic replicon cells but not by free virus particles, suggesting the existence of a novel cell-cell RNA transfer process whereby HCV-infected cells can activate pDCs to produce IFN without infecting them. These results may explain how HCV induces IFN production in the liver, and they reveal a heretofore unsuspected aspect of the innate host response to viruses that can subvert the classical sensing machinery in the cells they infect, and do not infect or directly activate pDCs.

  16. Apical dendrite degeneration, a novel cellular pathology for Betz cells in ALS

    PubMed Central

    Genç, Barış; Jara, Javier H.; Lagrimas, Amiko K. B.; Pytel, Peter; Roos, Raymond P.; Mesulam, M. Marsel; Geula, Changiz; Bigio, Eileen H.; Özdinler, P. Hande

    2017-01-01

    Apical dendrites of Betz cells are important sites for the integration of cortical input, however their health has not been fully assessed in ALS patients. We investigated the primary motor cortices isolated from post-mortem normal control subjects, patients with familial ALS (fALS), sporadic ALS (sALS), ALS with frontotemporal dementia (FTD-ALS), and Alzheimer’s disease (AD), and found profound apical dendrite degeneration of Betz cells in both fALS and sALS, as well as FTD-ALS patients. In contrast, Betz cells of AD patients and normal controls retain cellular integrity in the motor cortex, and CA1 pyramidal neurons show abnormalities predominantly within their soma, rather than the apical dendrite. In line with extensive vacuolation and cytoarchitectural disintegration, the numbers of synapses were also significantly reduced only in ALS patients. Our findings indicate apical dendrite degeneration as a novel cellular pathology that distinguishes ALS and further support the importance of cortical dysfunction for disease pathology. PMID:28165465

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

    PubMed Central

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

    2016-01-01

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

  18. Apical dendrite degeneration, a novel cellular pathology for Betz cells in ALS.

    PubMed

    Genç, Barış; Jara, Javier H; Lagrimas, Amiko K B; Pytel, Peter; Roos, Raymond P; Mesulam, M Marsel; Geula, Changiz; Bigio, Eileen H; Özdinler, P Hande

    2017-02-06

    Apical dendrites of Betz cells are important sites for the integration of cortical input, however their health has not been fully assessed in ALS patients. We investigated the primary motor cortices isolated from post-mortem normal control subjects, patients with familial ALS (fALS), sporadic ALS (sALS), ALS with frontotemporal dementia (FTD-ALS), and Alzheimer's disease (AD), and found profound apical dendrite degeneration of Betz cells in both fALS and sALS, as well as FTD-ALS patients. In contrast, Betz cells of AD patients and normal controls retain cellular integrity in the motor cortex, and CA1 pyramidal neurons show abnormalities predominantly within their soma, rather than the apical dendrite. In line with extensive vacuolation and cytoarchitectural disintegration, the numbers of synapses were also significantly reduced only in ALS patients. Our findings indicate apical dendrite degeneration as a novel cellular pathology that distinguishes ALS and further support the importance of cortical dysfunction for disease pathology.

  19. Transcriptional Classification and Functional Characterization of Human Airway Macrophage and Dendritic Cell Subsets.

    PubMed

    Patel, Vineet I; Booth, J Leland; Duggan, Elizabeth S; Cate, Steven; White, Vicky L; Hutchings, David; Kovats, Susan; Burian, Dennis M; Dozmorov, Mikhail; Metcalf, Jordan P

    2017-02-01

    The respiratory system is a complex network of many cell types, including subsets of macrophages and dendritic cells that work together to maintain steady-state respiration. Owing to limitations in acquiring cells from healthy human lung, these subsets remain poorly characterized transcriptionally and phenotypically. We set out to systematically identify these subsets in human airways by developing a schema of isolating large numbers of cells by whole-lung bronchoalveolar lavage. Six subsets of phagocytic APC (HLA-DR(+)) were consistently observed. Aside from alveolar macrophages, subsets of Langerin(+), BDCA1(-)CD14(+), BDCA1(+)CD14(+), BDCA1(+)CD14(-), and BDCA1(-)CD14(-) cells were identified. These subsets varied in their ability to internalize Escherichia coli, Staphylococcus aureus, and Bacillus anthracis particles. All subsets were more efficient at internalizing S. aureus and B. anthracis compared with E. coli Alveolar macrophages and CD14(+) cells were overall more efficient at particle internalization compared with the four other populations. Subsets were further separated into two groups based on their inherent capacities to upregulate surface CD83, CD86, and CCR7 expression levels. Whole-genome transcriptional profiling revealed a clade of "true dendritic cells" consisting of Langerin(+), BDCA1(+)CD14(+), and BDCA1(+)CD14(-) cells. The dendritic cell clade was distinct from a macrophage/monocyte clade, as supported by higher mRNA expression levels of several dendritic cell-associated genes, including CD1, FLT3, CX3CR1, and CCR6 Each clade, and each member of both clades, was discerned by specific upregulated genes, which can serve as markers for future studies in healthy and diseased states.

  20. Melanomas and Dysplastic Nevi Differ in Epidermal CD1c+ Dendritic Cell Count

    PubMed Central

    Dyduch, Grzegorz; Tyrak, Katarzyna Ewa; Glajcar, Anna; Szpor, Joanna

    2017-01-01

    Background. Dendritic cells could be involved in immune surveillance of highly immunogenic tumors such as melanoma. Their role in the progression melanocytic nevi to melanoma is however a matter of controversy. Methods. The number of dendritic cells within epidermis, in peritumoral zone, and within the lesion was counted on slides immunohistochemically stained for CD1a, CD1c, DC-LAMP, and DC-SIGN in 21 of dysplastic nevi, 27 in situ melanomas, and 21 invasive melanomas. Results. We found a significant difference in the density of intraepidermal CD1c+ cells between the examined lesions; the mean CD1c cell count was 7.00/mm2 for invasive melanomas, 2.94 for in situ melanomas, and 13.35 for dysplastic nevi. The differences between dysplastic nevi and melanoma in situ as well as between dysplastic nevi and invasive melanoma were significant. There was no correlation in number of positively stained cells between epidermis and dermis. We did not observe any intraepidermal DC-LAMP+ cells neither in melanoma in situ nor in invasive melanoma as well as any intraepidermal DC-SIGN+ cells in dysplastic nevi. Conclusion. It was shown that the number of dendritic cells differs between dysplastic nevi, in situ melanomas, and invasive melanomas. This could eventually suggest their participation in the development of melanoma. PMID:28331853

  1. 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.

  2. 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

  3. 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.

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

    PubMed

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

    2014-05-15

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

  5. In Vivo Targeting of Antigens to Maturing Dendritic Cells via the DEC-205 Receptor Improves T Cell Vaccination

    PubMed Central

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

    2004-01-01

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell–mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models. PMID:15024047

  6. 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.

  7. 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

  8. Macrophages Are Required for Dendritic Cell Uptake of Respiratory Syncytial Virus from an Infected Epithelium

    PubMed Central

    Ugonna, Kelechi; Bingle, Colin D.; Plant, Karen; Wilson, Kirsty; Everard, Mark L.

    2014-01-01

    We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells. PMID:24651119

  9. Macrophages are required for dendritic cell uptake of respiratory syncytial virus from an infected epithelium.

    PubMed

    Ugonna, Kelechi; Bingle, Colin D; Plant, Karen; Wilson, Kirsty; Everard, Mark L

    2014-01-01

    We have previously shown that the respiratory syncytial virus [RSV] can productively infect monocyte derived dendritic cells [MoDC] and remain dormant within the same cells for prolonged periods. It is therefore possible that infected dendritic cells act as a reservoir within the airways of individuals between annual epidemics. In the present study we explored the possibility that sub-epithelial DCs can be infected with RSV from differentiated bronchial epithelium and that in turn RSV from DCs can infect the epithelium. A dual co-culture model was established in which a differentiated primary airway epithelium on an Air Liquid Interface (ALI) was cultured on a transwell insert and MoDCs were subsequently added to the basolateral membrane of the insert. Further experiments were undertaken using a triple co-culture model in which in which macrophages were added to the apical surface of the differentiated epithelium. A modified RSV [rr-RSV] expressing a red fluorescent protein marker of replication was used to infect either the MoDCs or the differentiated epithelium and infection of the reciprocal cell type was assessed using confocal microscopy. Our data shows that primary epithelium became infected when rr-RSV infected MoDCs were introduced onto the basal surface of the transwell insert. MoDCs located beneath the epithelium did not become infected with virus from infected epithelial cells in the dual co-culture model. However when macrophages were present on the apical surface of the primary epithelium infection of the basal MoDCs occurred. Our data suggests that RSV infected dendritic cells readily transmit infection to epithelial cells even when they are located beneath the basal layer. However macrophages appear to be necessary for the transmission of infection from epithelial cells to basal dendritic cells.

  10. The methodological approach for the generation of human dendritic cells from monocytes affects the maturation state of the resultant dendritic cells.

    PubMed

    Mucci, Ilaria; Legitimo, Annalisa; Compagnino, Marta; Consolini, Rita; Migliaccio, Pasquale; Metelli, Maria Rita; Scatena, Fabrizio

    2009-10-01

    Dendritic cells (DCs) are effective as antigen-presenting cells in the immune system and are present at two functional stages depending on their maturation state. For experimental investigation of this concept, CD14(+) monocytes from blood are isolated and cultured to generate in vitro the DCs needed for functional analysis. For positive selection of CD14(+) monocytes we compared two immunomagnetic bead technologies: MACS Separation, created by Miltenyi Biotec, and EasySep Selection, created by StemCell Technologies. The monocytes provided dendritic cells for their functional analysis. Lipopolysaccharide was added to cultured DCs to induce maturation. Although both systems generated DCs from the positively selected CD14(+) cells, there were certain differences between them. Morphological, phenotypic, and functional analysis showed that MACS-selection provided DCs that have typical features corresponding to day 6 or 7 of maturation. EasySep-DCs exist in a partially-mature state from day 6 onward, even without the addition of a maturation stimulus. The reason behind this partial maturation is possibly based on the dextran-coated beads that are associated with the EasySep product. Both methods provide pure and viable DCs, but we would recommend using the MACS system for obtaining DCs suitable for functional studies.

  11. Regulation of immunologic homeostasis in peripheral tissues by dendritic cells: the respiratory tract as a paradigm.

    PubMed

    Holt, P G; Stumbles, P A

    2000-03-01

    Dendritic cells are now recognized as the gatekeepers of the immune response, possessing a unique potential for acquisition of antigens at extremely low exposure levels and for efficient presentation of these in an immunogenic form to the naive T-cell system. Dendritic cell populations throughout the body exhibit a wide range of features in common that are associated with their primary functions, and these are considered in the initial section of this review. In addition, it is becoming evident that the properties and functions of these cells are refined by microenvironmental factors unique to their tissues of residence, a prime example being mucosal microenvironments such as those in respiratory tract tissues, and the latter represents the focus of the second section of this review.

  12. Dendritic cells enhance UHMWPE wear particle-induced osteoclast differentiation of macrophages.

    PubMed

    Cang, Dingwei; Guo, Kaijin; Zhao, Fengchao

    2015-10-01

    Ultra-high molecular weight polyethylene (UHMWPE) has been widely used in large joint replacement. Osteolysis induced by the UHMWPE wear particles is one of the main causes of replacement failure. This study aims to elucidate whether dendritic cells play a role in UHMWPE particle-induced osteolysis. An in vitro Raw 264.7 and DC 2.4 coculture system was employed to examine the effects of dendritic cells on the inflammatory and osteoclastogenic responses of Raw 264.7 toward UHMWPE particles. The expression of cytokines, NF-κB, and osteoclast marker genes was analyzed by ELISA, western blot, or quantitative PCR. The osteoclast differentiation was measured by TRAP staining and flow cytometry. UHMWPE particles induced Raw 264.7 cells to differentiate into osteoclasts, which was enhanced by coculturing with DC 2.4 cells. DC 2.4 cells augmented UHMWPE particle-elicited activation of NF-κB signaling, higher levels of TNF-α and MCP-1, and an increased expression of MMP-9, Calcr, and Ctsk, though DC 2.4 coculture alone did not significantly cause the aforementioned changes. These results suggest that dendritic cells, among other immune cells recruited by UHMWPE particle induced inflammation, could further exacerbate inflammation and osteolysis.

  13. Desirable cytolytic immune effector cell recruitment by interleukin-15 dendritic cells.

    PubMed

    Van Acker, Heleen H; Beretta, Ottavio; Anguille, Sébastien; Caluwé, Lien De; Papagna, Angela; Van den Bergh, Johan M; Willemen, Yannick; Goossens, Herman; Berneman, Zwi N; Van Tendeloo, Viggo F; Smits, Evelien L; Foti, Maria; Lion, Eva

    2017-01-13

    Success of dendritic cell (DC) therapy in treating malignancies is depending on the DC capacity to attract immune effector cells, considering their reciprocal crosstalk is partially regulated by cell-contact-dependent mechanisms. Although critical for therapeutic efficacy, immune cell recruitment is a largely overlooked aspect regarding optimization of DC vaccination. In this paper we have made a head-to-head comparison of interleukin (IL)-15-cultured DCs and conventional IL-4-cultured DCs with regard to their proficiency in the recruitment of (innate) immune effector cells. Here, we demonstrate that IL-4 DCs are suboptimal in attracting effector lymphocytes, while IL15 DCs provide a favorable chemokine milieu for recruiting CD8+ T cells, natural killer (NK) cells and gamma delta (γδ) T cells. Gene expression analysis revealed that IL-15 DCs exhibit a high expression of chemokines involved in antitumor immune effector cell attraction, while IL-4 DCs display a more immunoregulatory profile characterized by the expression of Th2 and regulatory T cell-attracting chemokines. This is confirmed by functional data indicating an enhanced recruitment of granzyme B+ effector lymphocytes by IL-15 DCs, as compared to IL-4 DCs, and subsequent superior killing of tumor cells by the migrated lymphocytes. Elevated CCL4 gene expression in IL-15 DCs and lowered CCR5 expression on both migrated γδ T cells and NK cells, led to validation of increased CCL4 secretion by IL15 DCs. Moreover, neutralization of CCR5 prior to migration resulted in an important inhibition of γδ T cell and NK cell recruitment by IL-15 DCs. These findings further underscore the strong immunotherapeutic potential of IL-15 DCs.

  14. Vessel wall-embedded dendritic cells induce T-cell autoreactivity and initiate vascular inflammation.

    PubMed

    Han, Ji W; Shimada, Kazunori; Ma-Krupa, Wei; Johnson, Tiffany L; Nerem, Robert M; Goronzy, Jörg J; Weyand, Cornelia M

    2008-03-14

    Human medium-sized and large arteries are targeted by inflammation with innate and adaptive immune responses occurring within the unique microspace of the vessel wall. How 3D spatial arrangements influence immune recognition and cellular response thresholds and which cell populations sense immunoactivating ligands and function as antigen-presenting cells are incompletely understood. To mimic the 3D context of human arteries, bioartificial arteries were engineered from collagen type I matrix, human vascular smooth muscle cells (VSMCs), and human endothelial cells and populated with cells implicated in antigen presentation and T-cell stimulation, including monocytes, macrophages, and myeloid dendritic cells (DCs). Responsiveness of wall-embedded antigen-presenting cells was probed with the Toll-like receptor ligand lipopolysaccharide, and inflammation was initiated by adding autologous CD4(+) T cells. DCs colonized the outermost VSMC layer, recapitulating their positioning at the media-adventitia border of normal arteries. Wall-embedded DCs responded to the microbial product lipopolysaccharide by entering the maturation program and upregulating the costimulatory ligand CD86. Activated DCs effectively stimulated autologous CD4 T cells, which produced the proinflammatory cytokine interferon-gamma and infiltrated deeply into the VSMC layer, causing matrix damage. Lipopolysaccharide-triggered macrophages were significantly less efficacious in recruiting T cells and promoting T-cell stimulation. CD14(+) monocytes, even when preactivated, failed to support initial steps of vascular wall inflammation. Innate immune cells, including monocytes, macrophages, and DCs, display differential functions in the vessel wall. DCs are superior in sensing pathogen-derived motifs and are highly efficient in breaking T-cell tolerance, guiding T cells toward proinflammatory and tissue-invasive behavior.

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

    PubMed

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

    2005-02-01

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

  16. Isolation of dendritic cells from umbilical cord blood using magnetic activated cell sorting or adherence.

    PubMed

    Bie, Yachun; Xu, Qiuxiang; Zhang, Zhenyu

    2015-07-01

    Dendritic cells (DCs) are a highly specialized type of antigen-presenting cell. The present study describes and compares two methods for preparing DCs from umbilical cord blood. The first method involves the isolation of DCs by magnetic activated cell sorting (MACS). This technique isolates CD34(+) cells from cord blood and induces the formation of DCs by the addition of cytokines, granulocyte macrophage colony-stimulating factor and interleukin-4. The second method involves the generation of large numbers of DCs from cord blood using an adherent method, which isolates umbilical cord blood mononuclear cells and induces DCs in the same conditions as those used in MACS. The DCs were harvested following 7 days of incubation and observed with an inverted microscope. The phenotype of the cells was then analyzed by flow cytometry. The results revealed that, subsequent to 7 days of incubation, the differentiated DCs obtained using the adherent method were more mature than those isolated using MACS. However, these cells were unable to be maintained in culture for more than 9-10 days. By contrast, the DCs derived from CD34(+) cells by MACS were phenotypically stable and could be maintained for up to 3 weeks in culture. Either method produced DCs from cord blood. However, the DCs isolated using the MACS method demonstrated higher homogeneity, yield and viability than those obtained using the adherent method. Due to the various compositions of the monocyte subsets isolated, isolation methods affect the phenotypes and functions of the resultant DCs.

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

    PubMed

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

    2003-12-01

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

  18. 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

  19. NK cells enhance dendritic cell response against parasite antigens via NKG2D pathway.

    PubMed

    Guan, Hongbing; Moretto, Magali; Bzik, David J; Gigley, Jason; Khan, Imtiaz A

    2007-07-01

    Recent studies have shown that NK-dendritic cell (DC) interaction plays an important role in the induction of immune response against tumors and certain viruses. Although the effect of this interaction is bidirectional, the mechanism or molecules involved in this cross-talk have not been identified. In this study, we report that coculture with NK cells causes several fold increase in IL-12 production by Toxoplasma gondii lysate Ag-pulsed DC. This interaction also leads to stronger priming of Ag-specific CD8+ T cell response by these cells. In vitro blockade of NKG2D, a molecule present on human and murine NK cells, neutralizes the NK cell-induced up-regulation of DC response. Moreover, treatment of infected animals with Ab to NKG2D receptor compromises the development of Ag-specific CD8+ T cell immunity and reduces their ability to clear parasites. These studies emphasize the critical role played by NKG2D in the NK-DC interaction, which apparently is important for the generation of robust CD8+ T cell immunity against intracellular pathogens. To the best of our knowledge, this is the first work that describes in vivo importance of NKG2D during natural infection.

  20. Hypoxia skews dendritic cells to a T helper type 2-stimulating phenotype and promotes tumour cell migration by dendritic cell-derived osteopontin

    PubMed Central

    Yang, Meixiang; Ma, Chunhong; Liu, Shuxun; Sun, Jintang; Shao, Qianqian; Gao, Wenjuan; Zhang, Yan; Li, Zewu; Xie, Qi; Dong, Zhaogang; Qu, Xun

    2009-01-01

    It is well recognized that tissue microenvironments are involved in regulating the development and function of dendritic cells (DC). Oxygen supply, which varies in different tissues, has been accepted as an important microenvironmental factor in regulating the biological functions of several immune cells and as being involved in tumour progression and metastasis. However, little is known about the effect of hypoxia on the biological functions of DC and the effect of these hypoxia-conditioned DC on tumour metastasis. In this study, we analysed the transcriptional profiles of human monocyte-derived immature DC (imDC) and mature DC (mDC) cultured under normoxia and hypoxia by microarray, and found a body of potential targets regulating the functions of DC during hypoxia. In addition, the phagocytic ability of hypoxic imDC markedly decreased compared with that of normoxic imDC. Importantly, hypoxic DC poorly induced the proliferation of allogeneic T cells, but polarized allogeneic CD4+ naive T cells into a T helper type 2 (Th2) response. Moreover, hypoxic DC secreted large amounts of osteopontin, which were responsible for the enhanced migration of tumour cells. Therefore, our study provides new insights into the biological functions of DC under hypoxic conditions and one of mechanisms underlying tumour immune escape during hypoxia. PMID:19740309

  1. Clonally related Histiocytic/dendritic cell sarcoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: A study of 7 cases

    PubMed Central

    Shao, Haipeng; Xi, Liqiang; Raffeld, Mark; Feldman, Andrew L.; Ketterling, Rhett P.; Knudson, Ryan; Rodriguez-Canales, Jaime; Hanson, Jeffrey; Pittaluga, Stefania; Jaffe, Elaine S

    2011-01-01

    Histiocytic and interdigitating dendritic cell sarcomas are rare tumors originating from bone marrow derived myeloid stem cells. Recent studies have shown evidence of cross-lineage transdifferentiation of B-cells in follicular lymphoma to histiocytic and dendritic cell sarcomas. In this study, we report the morphologic, molecular and cytogenetic analysis of 7 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma associated with histiocytic and dendritic cell sarcomas. All seven patients were elderly males (median age, 71 years). The B-cell neoplasms preceded the development of the histiocytic and dendritic cell sarcomas in 6 of 7 patients, and one patient had both tumors diagnosed at the same time. The tumors included 4 interdigitating dendritic cell sarcomas; 1 Langerhans cell sarcoma, 1 histiocytic sarcoma, and 1 immature neoplasm with evidence of histiocytic origin. Laser-capture microdissection and PCR analysis showed identical clonal immunoglobulin gene rearrangements in the two phenotypically distinct components in all cases. There was a preferential usage of IGHV4-39 by the V-D-J gene rearrangement. By FISH analysis two cases showed deletion 17p in both components, while 4 cases had normal cytogenetic findings by FISH in the CLL/SLL cells, but acquired cytogenetic abnormalities in the corresponding histiocytic and dendritic tumors. Chromosome 17p abnormalities were the most common cytogenetic abnormality detected in the sarcomas, seen in 5 of 6 cases studied. Compared with the CLL/SLL cells, the histiocytic/dendritic cells were largely negative for PAX5, but showed strong expression of PU.1 and variable and weak expression of CEBPβ. Our study provides evidence for transdifferentiation of CLL/SLL B-cells to tumors of dendritic and less often histiocytic lineage, and suggests that secondary genetic events may play a role in this phenomenon. PMID:21666687

  2. Signaling network of dendritic cells in response to pathogens: a community-input supported knowledgebase

    PubMed Central

    2010-01-01

    Background Dendritic cells are antigen-presenting cells that play an essential role in linking the innate and adaptive immune systems. Much research has focused on the signaling pathways triggered upon infection of dendritic cells by various pathogens. The high level of activity in the field makes it desirable to have a pathway-based resource to access the information in the literature. Current pathway diagrams lack either comprehensiveness, or an open-access editorial interface. Hence, there is a need for a dependable, expertly curated knowledgebase that integrates this information into a map of signaling networks. Description We have built a detailed diagram of the dendritic cell signaling network, with the goal of providing researchers with a valuable resource and a facile method for community input. Network construction has relied on comprehensive review of the literature and regular updates. The diagram includes detailed depictions of pathways activated downstream of different pathogen recognition receptors such as Toll-like receptors, retinoic acid-inducible gene-I-like receptors, C-type lectin receptors and nucleotide-binding oligomerization domain-like receptors. Initially assembled using CellDesigner software, it provides an annotated graphical representation of interactions stored in Systems Biology Mark-up Language. The network, which comprises 249 nodes and 213 edges, has been web-published through the Biological Pathway Publisher software suite. Nodes are annotated with PubMed references and gene-related information, and linked to a public wiki, providing a discussion forum for updates and corrections. To gain more insight into regulatory patterns of dendritic cell signaling, we analyzed the network using graph-theory methods: bifan, feedforward and multi-input convergence motifs were enriched. This emphasis on activating control mechanisms is consonant with a network that subserves persistent and coordinated responses to pathogen detection

  3. REMOD: A Tool for Analyzing and Remodeling the Dendritic Architecture of Neural Cells

    PubMed Central

    Bozelos, Panagiotis; Stefanou, Stefanos S.; Bouloukakis, Georgios; Melachrinos, Constantinos; Poirazi, Panayiota

    2016-01-01

    Dendritic morphology is a key determinant of how individual neurons acquire a unique signal processing profile. The highly branched dendritic structure that originates from the cell body, explores the surrounding 3D space in a fractal-like manner, until it reaches a certain amount of complexity. Its shape undergoes significant alterations under various physiological or neuropathological conditions. Yet, despite the profound effect that these alterations can have on neuronal function, the causal relationship between the two remains largely elusive. The lack of a systematic approach for remodeling neural cells and their dendritic trees is a key limitation that contributes to this problem. Such causal relationships can be inferred via the use of large-scale neuronal models whereby the anatomical plasticity of neurons is accounted for, in order to enhance their biological relevance and hence their predictive performance. To facilitate this effort, we developed a computational tool named REMOD that allows the structural remodeling of any type of virtual neuron. REMOD is written in Python and can be accessed through a dedicated web interface that guides the user through various options to manipulate selected neuronal morphologies. REMOD can also be used to extract meaningful morphology statistics for one or multiple reconstructions, including features such as sholl analysis, total dendritic length and area, path length to the soma, centrifugal branch order, diameter tapering and more. As such, the tool can be used both for the analysis and/or the remodeling of neuronal morphologies of any type. PMID:26778971

  4. In vivo blockade of neural activity alters dendritic development of neonatal CA1 pyramidal cells.

    PubMed

    Groc, Laurent; Petanjek, Zdravko; Gustafsson, Bengt; Ben-Ari, Yehezkel; Hanse, Eric; Khazipov, Roustem

    2002-11-01

    During development, neural activity has been proposed to promote neuronal growth. During the first postnatal week, the hippocampus is characterized by an oscillating neural network activity and a rapid neuronal growth. In the present study we tested in vivo, by injecting tetanus toxin into the hippocampus of P1 rats, whether this neural activity indeed promotes growth of pyramidal cells. We have previously shown that tetanus toxin injection leads to a strong reduction in the frequency of spontaneous GABA and glutamatergic synaptic currents, and to a complete blockade of the early neural network activity during the first postnatal week. Morphology of neurobiotin-filled CA1 pyramidal cells was analyzed at the end of the first postnatal week (P6-10). In activity-reduced neurons, the total length of basal dendritic tree was three times less than control. The number, but not the length, of basal dendritic branches was affected. The growth impairment was restricted to the basal dendrites. The apical dendrite, the axons, or the soma grew normally during activity deprivation. Thus, the in vivo neural activity in the neonate hippocampus seems to promote neuronal growth by initiating novel branches.

  5. REMOD: A Tool for Analyzing and Remodeling the Dendritic Architecture of Neural Cells.

    PubMed

    Bozelos, Panagiotis; Stefanou, Stefanos S; Bouloukakis, Georgios; Melachrinos, Constantinos; Poirazi, Panayiota

    2015-01-01

    Dendritic morphology is a key determinant of how individual neurons acquire a unique signal processing profile. The highly branched dendritic structure that originates from the cell body, explores the surrounding 3D space in a fractal-like manner, until it reaches a certain amount of complexity. Its shape undergoes significant alterations under various physiological or neuropathological conditions. Yet, despite the profound effect that these alterations can have on neuronal function, the causal relationship between the two remains largely elusive. The lack of a systematic approach for remodeling neural cells and their dendritic trees is a key limitation that contributes to this problem. Such causal relationships can be inferred via the use of large-scale neuronal models whereby the anatomical plasticity of neurons is accounted for, in order to enhance their biological relevance and hence their predictive performance. To facilitate this effort, we developed a computational tool named REMOD that allows the structural remodeling of any type of virtual neuron. REMOD is written in Python and can be accessed through a dedicated web interface that guides the user through various options to manipulate selected neuronal morphologies. REMOD can also be used to extract meaningful morphology statistics for one or multiple reconstructions, including features such as sholl analysis, total dendritic length and area, path length to the soma, centrifugal branch order, diameter tapering and more. As such, the tool can be used both for the analysis and/or the remodeling of neuronal morphologies of any type.

  6. Ebola Virus: The Role of Macrophages and Dendritic Cells in the Pathogenesis of Ebola Hemorrhagic Fever

    DTIC Science & Technology

    2007-11-02

    monkeys by aerosolized Ebola virus . Int. J. Exp. Pathol., 76(4), 227–236. Mahanty, S., & Bray, M. (2004). Pathogenesis of filoviral haemor- rhagic...Impairment of den- dritic cells and adaptive immunity by Ebola and Lassa viruses . J. Immunol., 170(6), 2797–2801. Reed, D. S., Hensley, L. E., Geisbert, J...The International Journal of Biochemistry & Cell Biology 37 (2005) 1560–1566 Medicine in focus Ebola virus : The role of macrophages and dendritic

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

    PubMed

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

    2008-03-01

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

  8. Myeloid dendritic cells frequencies are increased in children with autism spectrum disorder and associated with amygdala volume and repetitive behaviors

    PubMed Central

    Breece, Elizabeth; Paciotti, Brian; Nordahl, Christine Wu; Ozonoff, Sally; Van de Water, Judy A.; Rogers, Sally J.; Amaral, David; Ashwood, Paul

    2012-01-01

    The pathophysiology of Autism Spectrum Disorder (ASD) is not yet known; however, studies suggest that dysfunction of the immune system affects many children with ASD. Increasing evidence points to dysfunction of the innate immune system including activation of microglia and perivascular macrophages, increases in inflammatory cytokines/chemokines in brain tissue and CSF, and abnormal peripheral monocyte cell function. Dendritic cells are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, antigen presentation, activation of naïve T cells, induction of tolerance and cytokine/chemokine production. In this study, we assessed circulating frequencies of myeloid dendritic cells (defined as Lin-1−BDCA1+CD11c+ and Lin-1−BDCA3+CD123−) and plasmacytoid dendritic cells (Lin-1− BDCA2+CD123+ or Lin-1−BDCA4+ CD11c−) in 57 children with ASD, and 29 typically developing controls of the same age, all of who were enrolled as part of the Autism Phenome Project (APP). The frequencies of dendritic cells and associations with behavioral assessment and MRI measurements of amygdala volume were compared in the same participants. The frequencies of myeloid dendritic cells were significantly increased in children with ASD compared to typically developing controls (p < 0.03). Elevated frequencies of myeloid dendritic cells were positively associated with abnormal right and left amygdala enlargement, severity of gastrointestinal symptoms and increased repetitive behaviors. The frequencies of plasmacytoid dendritic cells were also associated with amygdala volumes as well as developmental regression in children with ASD. Dendritic cells play key roles in modulating immune responses and differences in frequencies or functions of these cells may result in immune dysfunction in children with ASD. These data further implicate innate immune cells in the complex pathophysiology of ASD. PMID:23063420

  9. Fusions of Breast Carcinoma and Dendritic Cells as a Vaccine for the Treatment of Metastatic Breast Cancer

    DTIC Science & Technology

    2005-07-01

    regulate the development of anti-tumor immune responses . Importantly, our results show that, compared to unfused DC and tumor cells, the DC/ breast tumor...AD Award Number: DAMD17-03-1-0487 TITLE: Fusions of Breast Carcinoma and Dendritic Cells as a Vaccine for the Treatment of Metastatic Breast Cancer ...4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Fusions of Breast Carcinoma and Dendritic Cells as a Vaccine for the Treatment of Metastatic Breast Cancer

  10. Dendritic cell podosomes are protrusive and invade the extracellular matrix using metalloproteinase MMP-14

    PubMed Central

    Gawden-Bone, Christian; Zhou, Zhongjun; King, Emma; Prescott, Alan; Watts, Colin; Lucocq, John

    2010-01-01

    Podosomes are spot-like actin-rich structures formed at the ventral surface of monocytic and haematopoietic cells. Podosomes degrade extracellular matrix and are proposed to be involved in cell migration. A key question is whether podosomes form protrusions similar to the invadopodia of cancer cells. We characterised podosomes of immature dendritic cells using electron microscopy combined with both conventional and novel high-resolution structured illumination light microscopy. Dendritic cell podosomes are composed of actin foci surrounded by a specialised ring region that is rich in material containing paxillin. We found that podosomes were preferential sites for protrusion into polycarbonate filters impregnated with crosslinked gelatin, degrading up to 2 μm of matrix in 24 hours. Podosome-associated uptake of colloidal gold-labelled gelatin matrix appeared to occur via large phagosome-like structures or narrow tubular invaginations. The motor protein myosin-II was excluded from ring or core regions but was concentrated around them and the myosin-II inhibitor Blebbistatin reduced the length of podosome protrusions. Finally, we found that degradation, protrusion and endocytosis in this system are dependent on the matrix metalloproteinase MMP-14. We propose that podosomes mediate migration of dendritic cells through tissues by means of myosin-II-dependent protrusion coupled to MMP-14-dependent degradation and endocytosis. PMID:20356925

  11. Influence of Immunotherapy with Autologous Dendritic Cells on Innate and Adaptive Immune Response in Cancer

    PubMed Central

    Matias, Bruna F.; de Oliveira, Tânia M.; Rodrigues, Cláudia M.; Abdalla, Douglas R.; Montes, Letícia; Murta, Eddie F.C.; Michelin, Márcia A.

    2013-01-01

    The objective of this study was to evaluate some of the mechanisms involved in the activation of the immune system in patients with advanced-stage cancer (n = 7) who received an autologous dendritic cell vaccine. We examined the immune response mediated by macrophages (CD14+), natural killer cells (CD56+), and B lymphocytes (CD19+) by flow cytometry and assessed the expression of Th1 (IFN-γ, TNF-α, IL-2, and IL-12), Th2 (IL-4), and Treg (TGF-β) cytokines by flow cytometry and an enzyme-linked immunosorbent assay. The CD14+ TNF-α+ population was significantly increased (P < 0.04) when patients received the vaccine; IL-2 expression in both NK cells and in B lymphocytes was increased after a transient initial increase showed a nearly significant decrease (P < 0.07 and P < 0.06 respectively), whereas the CD19+ and CD56+ populations did not show significant changes. Dendritic cell-based immunotherapy led to increased secretion of IFN-γ and IL-12 and reduced secretion of TGF-β. In conclusion, it is likely that the autologous dendritic cell vaccine stimulated the immune cells from the peripheral blood of patients with cancer and generally increased the production of Th1 cytokines, which are related to immunomodulatory responses against cancer. PMID:23926442

  12. Early postweaning social isolation but not environmental enrichment modifies vermal Purkinje cell dendritic outgrowth in rats.

    PubMed

    Pascual, Rodrigo; Bustamante, Carlos

    2013-01-01

    In the present study, we analyzed the effects of enriched, social and isolated experiences on vermal Purkinje cell of the rat, together with anxiety-like behavior in the elevated-plus maze. Sprague-Dawley male rats were randomly submitted to either enriched, social, or isolated environments during the early postweaning period (postnatal days 22-32) and were then behaviorally evaluated in the elevated-plus maze and euthanized for histological analysis. Vermal Purkinje cells (sub-lobules VIa and VIb) were sampled, drawn under camera lucida and morphometrically assessed using the Sholl's concentric ring method. Data obtained indicate that environmental enrichment did not significantly modify the Purkinje cell dendritic branching. On the contrary, Purkinje cell of animals reared in social isolation exhibited a significant reduction in dendritic arborization, which was closely associated with anxiety-like behaviors. The data obtained indicate that, although environmental stimulation in normal animals does not produce significant changes in vermal Purkinje cell dendritic arborization, these cells are vulnerable to early stressful experiences, which is in close association with anxiety-like behaviors.

  13. PHBV microspheres as neural tissue engineering scaffold support neuronal cell growth and axon-dendrite polarization.

    PubMed

    Chen, Wenhui; Tong, Yen Wah

    2012-02-01

    Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres, with properties such as slower degradation and more efficient drug delivery properties, have important benefits for neural tissue engineering. Our previous studies have shown PHBV microspheres to improve cell growth and differentiation. This study aimed to investigate if PHBV microspheres would support neurons to extend these benefits to neural tissue engineering. PHBV microspheres' suitability as neural tissue engineering scaffolds was investigated using PC12 cells, cortical neurons (CNs), and neural progenitor cells (NPCs) to cover a variety of neuronal types for different applications. Microspheres were fabricated using an emulsion-solvent-evaporation technique. DNA quantification, cell viability assays, and immunofluorescent staining were carried out. PC12 cultures on PHBV microspheres showed growth trends comparable to two-dimensional controls. This was further verified by staining for cell spreading. Also, CNs expressed components of the signaling pathway on PHBV microspheres, and had greater axon-dendrite segregation (4.1 times for axon stains and 2.3 times for dendrite stains) than on coverslips. NPCs were also found to differentiate into neurons on the microspheres. Overall, the results indicate that PHBV microspheres, as scaffolds for neural tissue engineering, supported a variety of neuronal cell types and promoted greater axon-dendrite segregation.

  14. Aminopeptidase N (CD13) Is Involved in Phagocytic Processes in Human Dendritic Cells and Macrophages

    PubMed Central

    Villaseñor-Cardoso, Mónica I.; Frausto-Del-Río, Dulce A.

    2013-01-01

    Aminopeptidase N (APN or CD13) is a membrane ectopeptidase expressed by many cell types, including myelomonocytic lineage cells: monocytes, macrophages, and dendritic cells. CD13 is known to regulate the biological activity of various peptides by proteolysis, and it has been proposed that CD13 also participates in several functions such as angiogenesis, cell adhesion, metastasis, and tumor invasion. We had previously reported that, in human monocytes and macrophages, CD13 modulates the phagocytosis mediated by receptors for the Fc portion of IgG antibodies (FcγRs). In this work, we analyzed the possible interaction of CD13 with other phagocytic receptors. We found out that the cross-linking of CD13 positively modulates the phagocytosis mediated by receptors of the innate immune system, since a significant increase in the phagocytosis of zymosan particles or heat-killed E. coli was observed when CD13 was cross-linked using anti-CD13 antibodies, in both macrophages and dendritic cells. Also, we observed that, during the phagocytosis of zymosan, CD13 redistributes and is internalized into the phagosome. These findings suggest that, besides its known functions, CD13 participates in phagocytic processes in dendritic cells and macrophages. PMID:24063007

  15. Dynamic interplay among monocyte-derived, dermal, and resident lymph node dendritic cells during the generation of vaccine immunity to fungi.

    PubMed

    Ersland, Karen; Wüthrich, Marcel; Klein, Bruce S

    2010-06-25

    Early innate events that enable priming of antifungal CD4 T cells are poorly understood. We engineered an attenuated fungal vaccine with a model epitope, EalphaRFP, to track vaccine immunity to Blastomyces dermatitidis during yeast recognition, antigen presentation, and priming of naive T cells. After subcutaneous injection of the vaccine, monocyte-derived inflammatory dendritic cells (DCs) are the earliest and largest population that associates with yeast, carrying them into the draining lymph nodes. Despite marked association with yeast, these DCs fail to display surface peptide:MHC complexes or prime naive T cells. Instead, the ability to display antigen and prime CD4 T cells resides with lymph node-resident DCs after antigen transfer from immigrant DCs and with skin migratory DCs. Our work reveals the dynamic interplay among distinct DC subsets that prime naive CD4 T cells after yeast are injected in the skin and discloses the cellular elements underlying vaccine-induced immunity to fungi.

  16. Bridging channel dendritic cells induce immunity to transfused red blood cells

    PubMed Central

    Calabro, Samuele; Gallman, Antonia; Gowthaman, Uthaman; Liu, Dong; Chen, Pei; Liu, Jingchun; Krishnaswamy, Jayendra Kumar; Nascimento, Manuela Sales L.; Xu, Lan; Patel, Seema R.; Williams, Adam; Tormey, Christopher A.; Hod, Eldad A.; Spitalnik, Steven L.; Zimring, James C.; Hendrickson, Jeanne E.; Stowell, Sean R.

    2016-01-01

    Red blood cell (RBC) transfusion is a life-saving therapeutic tool. However, a major complication in transfusion recipients is the generation of antibodies against non-ABO alloantigens on donor RBCs, potentially resulting in hemolysis and renal failure. Long-lived antibody responses typically require CD4+ T cell help and, in murine transfusion models, alloimmunization requires a spleen. Yet, it is not known how RBC-derived antigens are presented to naive T cells in the spleen. We sought to answer whether splenic dendritic cells (DCs) were essential for T cell priming to RBC alloantigens. Transient deletion of conventional DCs at the time of transfusion or splenic DC preactivation before RBC transfusion abrogated T and B cell responses to allogeneic RBCs, even though transfused RBCs persisted in the circulation for weeks. Although all splenic DCs phagocytosed RBCs and activated RBC-specific CD4+ T cells in vitro, only bridging channel 33D1+ DCs were required for alloimmunization in vivo. In contrast, deletion of XCR1+CD8+ DCs did not alter the immune response to RBCs. Our work suggests that blocking the function of one DC subset during a narrow window of time during RBC transfusion could potentially prevent the detrimental immune response that occurs in patients who require lifelong RBC transfusion support. PMID:27185856

  17. Intestinal lamina propria dendritic cells maintain T cell homeostasis but do not affect commensalism.

    PubMed

    Welty, Nathan E; Staley, Christopher; Ghilardi, Nico; Sadowsky, Michael J; Igyártó, Botond Z; Kaplan, Daniel H

    2013-09-23

    Dendritic cells (DCs) in the intestinal lamina propria (LP) are composed of two CD103(+) subsets that differ in CD11b expression. We report here that Langerin is expressed by human LP DCs and that transgenic human langerin drives expression in CD103(+)CD11b(+) LP DCs in mice. This subset was ablated in huLangerin-DTA mice, resulting in reduced LP Th17 cells without affecting Th1 or T reg cells. Notably, cognate DC-T cell interactions were not required for Th17 development, as this response was intact in huLangerin-Cre I-Aβ(fl/fl) mice. In contrast, responses to intestinal infection or flagellin administration were unaffected by the absence of CD103(+)CD11b(+) DCs. huLangerin-DTA x BatF3(-/-) mice lacked both CD103(+) LP DC subsets, resulting in defective gut homing and fewer LP T reg cells. Despite these defects in LP DCs and resident T cells, we did not observe alterations of intestinal microbial communities. Thus, CD103(+) LP DC subsets control T cell homeostasis through both nonredundant and overlapping mechanisms.

  18. Linking CD11b+ Dendritic Cells and Natural Killer T Cells to Plaque Inflammation in Atherosclerosis

    PubMed Central

    Rombouts, Miche; Ammi, Rachid; Van Brussel, Ilse; Roth, Lynn; De Winter, Benedicte Y.; Vercauteren, Sven R.; Hendriks, Jeroen M. H.; Lauwers, Patrick; Van Schil, Paul E.; De Meyer, Guido R. Y.; Fransen, Erik; Cools, Nathalie; Schrijvers, Dorien M.

    2016-01-01

    Atherosclerosis remains the leading cause of death and disability in our Western society. To investigate whether the dynamics of leukocyte (sub)populations could be predictive for plaque inflammation during atherosclerosis, we analyzed innate and adaptive immune cell distributions in blood, plaques, and lymphoid tissue reservoirs in apolipoprotein E-deficient (ApoE−/−) mice and in blood and plaques from patients undergoing endarterectomy. Firstly, there was predominance of the CD11b+ conventional dendritic cell (cDC) subset in the plaque. Secondly, a strong inverse correlation was observed between CD11b+ cDC or natural killer T (NKT) cells in blood and markers of inflammation in the plaque (including CD3, T-bet, CCR5, and CCR7). This indicates that circulating CD11b+ cDC and NKT cells show great potential to reflect the inflammatory status in the atherosclerotic plaque. Our results suggest that distinct changes in inflammatory cell dynamics may carry biomarker potential reflecting atherosclerotic lesion progression. This not only is crucial for a better understanding of the immunopathogenesis but also bares therapeutic potential, since immune cell-based therapies are emerging as a promising novel strategy in the battle against atherosclerosis and its associated comorbidities. The cDC-NKT cell interaction in atherosclerosis serves as a good candidate for future investigations. PMID:27051078

  19. Migratory and lymphoid-resident dendritic cells cooperate to efficiently prime naive CD4 T cells.

    PubMed

    Allenspach, Eric J; Lemos, Maria P; Porrett, Paige M; Turka, Laurence A; Laufer, Terri M

    2008-11-14

    To initiate an adaptive immune response, rare antigen-specific naive CD4(+) T cells must interact with equally rare dendritic cells (DCs) bearing cognate peptide-major histocompatibility complex (MHC) complexes. Lymph nodes (LNs) draining the site of antigen entry are populated by lymphoid-resident DCs as well as DCs that have immigrated from tissues, although the requirement for each population in initiating the T cell response remains unclear. Here, we show that antigen processing and presentation by both lymphoid-resident and migratory DCs was required for clonal selection and expansion of CD4(+) T cells after subcutaneous immunization. Early antigen presentation by lymphoid-resident DCs initiated activation and trapping of antigen-specific T cells in the draining LN, without sufficing for clonal expansion. Migratory DCs, however, interacted with the CD4(+) T cells retained in the LN to induce proliferation. Therefore, distinct DC subsets cooperate to alert and trap the appropriate cell and then license its expansion and differentiation.

  20. The role of dendritic cells and regulatory T cells in the pathogenesis of morphea

    PubMed Central

    Teresiak-Mikołajczak, Ewa; Dańczak-Pazdrowska, Aleksandra; Kowalczyk, Michał; Żaba, Ryszard; Adamski, Zygmunt

    2015-01-01

    Morphea is one of diseases characterised by fibrosis of the skin and subcutaneous tissue. It is a chronic disease that does not shorten the life of the patient, yet significantly affects its quality. The group of factors responsible for its pathogenesis is thought to include disturbed functioning of endothelial cells as well as immune disturbances leading to chronic inflammatory conditions, accompanied by increased production of collagen and of other extracellular matrix components. Dendritic cells (DC) are a type of professional antigen-presenting cells and can be found in almost all body tissues. Individual investigations have demonstrated high numbers of plasmacytoid DC (pDC) in morphoeic skin lesions, within deeper dermal layers, around blood vessels, and around collagen fibres in subcutaneous tissue. It appears that DC has a more pronounced role in the development of inflammation and T cell activation in morphea, as compared to systemic sclerosis (SSc). Regulatory T (Treg) cells represent a subpopulation of T cells with immunosuppressive properties. Recent studies have drawn attention to the important role played by Treg in the process of autoimmunisation. Just a few studies have demonstrated a decrease in the number and activity of Treg in patients with SSc, and only such studies involve morphea. This article reviews recent studies on the role of DC and regulatory T cells in the pathogenesis of morphea. Moreover, mechanisms of phototherapy and potential therapeutic targets in the treatment of morphea are discussed in this context. PMID:26155191

  1. Dendritic cells respond to nasopharygeal carcinoma cells through annexin A2-recognizing DC-SIGN.

    PubMed

    Chao, Pin-Zhir; Hsieh, Ming-Shium; Cheng, Chao-Wen; Hsu, Tin-Jui; Lin, Yun-Tien; Lai, Chang-Hao; Liao, Chen-Chung; Chen, Wei-Yu; Leung, Ting-Kai; Lee, Fei-Peng; Lin, Yung-Feng; Chen, Chien-Ho

    2015-01-01

    Dendritic cells (DCs) play an essential role in immunity and are used in cancer immunotherapy. However, these cells can be tuned by tumors with immunosuppressive responses. DC-specific intercellular adhesion molecule 3-Grabbing Nonintegrin (DC-SIGN), a C-type lectin expressed on DCs, recognizes certain carbohydrate structures which can be found on cancer cells. Nasopharyngeal carcinoma (NPC) is an epithelial cell-derived malignant tumor, in which immune response remains unclear. This research is to reveal the molecular link on NPC cells that induces the immunosuppressive responses in DCs. In this article, we report identification of annexin A2 (ANXA2) on NPC cells as a ligand for DC-SIGN on DCs. N-linked mannose-rich glycan on ANXA2 may mediate the interaction. ANXA2 was abundantly expressed in NPC, and knockdown of ANXA2 suppressed NPC xenograft in mice, suggesting a crucial role of ANXA2 in NPC growth. Interaction with NPC cells caused DC-SIGN activation in DCs. Consequently DC maturation and the proinflammatory interleukin (IL)-12 production were inhibited, and the immunosuppressive IL-10 production was promoted. Blockage of either DC-SIGN or ANXA2 eliminated the production of IL-10 from DCs. This report suggests that suppression of ANXA2 at its expression or glycosylation on NPC may improve DC-mediated immunotherapy for the tumor.

  2. B7-Dc, a New Dendritic Cell Molecule with Potent Costimulatory Properties for T Cells

    PubMed Central

    Tseng, Su-Yi; Otsuji, Mizuto; Gorski, Kevin; Huang, Xin; Slansky, Jill E.; Pai, Sara I.; Shalabi, Ahmed; Shin, Tahiro; Pardoll, Drew M.; Tsuchiya, Haruo

    2001-01-01

    Dendritic cells (DCs), unique antigen-presenting cells (APCs) with potent T cell stimulatory capacity, direct the activation and differentiation of T cells by providing costimulatory signals. As such, they are critical regulators of both natural and vaccine-induced immune responses. A new B7 family member, B7-DC, whose expression is highly restricted to DCs, was identified among a library of genes differentially expressed between DCs and activated macrophages. B7-DC fails to bind the B7.1/2 receptors CD28 and cytotoxic T lymphocyte–associated antigen (CTLA)-4, but does bind PD-1, a receptor for B7-H1/PD-L1. B7-DC costimulates T cell proliferation more efficiently than B7.1 and induces a distinct pattern of lymphokine secretion. In particular, B7-DC strongly costimulates interferon γ but not interleukin (IL)-4 or IL-10 production from isolated naive T cells. These properties of B7-DC may account for some of the unique activity of DCs, such as their ability to initiate potent T helper cell type 1 responses. PMID:11283156

  3. 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.

  4. The Dendritic Cell Lineage: Ontogeny and Function of Dendritic Cells and Their Subsets in the Steady State and the Inflamed Setting

    PubMed Central

    Merad, Miriam; Sathe, Priyanka; Helft, Julie; Miller, Jennifer; Mortha, Arthur

    2013-01-01

    Dendritic cells (DCs) form a remarkable cellular network that shapes adaptive immune responses according to peripheral cues. After four decades of research, we now know that DCs arise from a hematopoietic lineage distinct from other leukocytes, establishing the DC system as a unique hematopoietic branch. Recent work has also established that tissue DCs consist of developmentally and functionally distinct subsets that differentially regulate T lymphocyte function. This review discusses major advances in our understanding of the regulation of DC lineage commitment, differentiation, diversification, and function in situ. PMID:23516985

  5. CD4+ CD25+ regulatory T cells prevent type 1 diabetes preceded by dendritic cell-dominant invasive insulitis by affecting chemotaxis and local invasiveness of dendritic cells.

    PubMed

    Lee, Mi-Heon; Lee, Wen-Hui; Todorov, Ivan; Liu, Chih-Pin

    2010-08-15

    Development of type 1 diabetes (T1D) is preceded by invasive insulitis. Although CD4(+)CD25(+) regulatory T cells (nTregs) induce tolerance that inhibits insulitis and T1D, the in vivo cellular mechanisms underlying this process remain largely unclear. Using an adoptive transfer model and noninvasive imaging-guided longitudinal analyses, we found nTreg depletion did not affect systemic trafficking and tissue localization of diabetogenic CD4(+) BDC2.5 T (BDC) cells in recipient mice prior to development of T1D. In addition, neither the initial expansion/activation of BDC cells nor the number of CD11c(+) or NK cells in islets and pancreatic lymph nodes were altered. Unexpectedly, our results showed nTreg depletion led to accelerated invasive insulitis dominated by CD11c(+) dendritic cells (ISL-DCs), not BDC cells, which stayed in the islet periphery. Compared with control mice, the phenotype of ISL-DCs and their ability to stimulate BDC cells did not change during invasive insulitis development. However, ISL-DCs from nTreg-deficient recipient mice showed increased in vitro migration toward CCL19 and CCL21. These results demonstrated invasive insulitis dominated by DCs, not CD4(+) T cells, preceded T1D onset in the absence of nTregs, and suggested a novel in vivo function of nTregs in T1D prevention by regulating local invasiveness of DCs into islets, at least partly, through regulation of DC chemotaxis toward CCL19/CCL21 produced by the islets.

  6. Efficient Killing of High Risk Neuroblastoma Using Natural Killer Cells Activated by Plasmacytoid Dendritic Cells

    PubMed Central

    Cordeau, Martine; Belounis, Assila; Lelaidier, Martin; Cordeiro, Paulo; Sartelet, Hervé; Duval, Michel

    2016-01-01

    High-risk neuroblastoma (NB) remains a major therapeutic challenge despite the recent advent of disialoganglioside (GD2)-antibody treatment combined with interleukin (IL)-2 and granulocyte monocyte-colony stimulating factor (GM-CSF). Indeed, more than one third of the patients still die from this disease. Here, we developed a novel approach to improve the current anti-GD2 immunotherapy based on NK cell stimulation using toll-like receptor (TLR)-activated plasmacytoid dendritic cells (pDCs). We demonstrated that this strategy led to the efficient killing of NB cells. When the expression of GD2 was heterogeneous on NB cells, the combination of pDC-mediated NK-cell activation and anti-GD2 treatment significantly increased the cytotoxicity of NK cells against NB cells. Activation by pDCs led to a unique NK-cell phenotype characterized by increased surface expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), with increased expression of CD69 on CD56dim cytotoxic cells, and strong interferon-γ production. Additionally, NB-cell killing was mediated by the TRAIL death-receptor pathway, as well as by the release of cytolytic granules via the DNAX accessory molecule 1 pathway. NK-cell activation and lytic activity against NB was independent of cell contact, depended upon type I IFN produced by TLR-9-activated pDCs, but was not reproduced by IFN-α stimulation alone. Collectively, these results highlighted the therapeutic potential of activated pDCs for patients with high-risk NB. PMID:27716850

  7. 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.

  8. Assessment of genetic markers and glioblastoma stem-like cells in activation of dendritic cells.

    PubMed

    Yurtsever, Aysel; Haydaroglu, Ayfer; Biray Avci, Cigir; Gunduz, Cumhur; Oktar, Nezih; Dalbasti, Tayfun; Caglar, Hasan Onur; Attar, Rukset; Kitapcioglu, Gul

    2013-09-01

    Glioblastoma (GBM) is the most common and aggressive intraparenchymal primary brain tumor in adults. The principal reasons for the poor outcomes of GBM are the high rates of recurrence and resistance to chemotherapy. The aim of this study was to determine the role of tailored cellular therapy for GBM with a poor prognosis and compare the activity of dendritic cells (DCs) that have encountered GBM cells. Detecting the correlations between methylation and expression of MGMT and PTEN genes and GBM cancer stem cells (CSCs) markers after co-cultures with a mononuclear cell cocktail are also aims for this study. Allogenic umbilical cord blood (UCB)-derived DCs were labeled with the CD11a and CD123 for immature DCs, and CD80 and CD11c for mature DCs. CD34, CD45, and CD56 cells were isolated from allogenic UCB for using in DCs maturation. GBM CSCs were detected with CD133/1 and CD111 antibodies after co-culture studies. DC activation was carried out via GBM cells including CD133 and CD111 cells and a mononuclear cells cocktail including CD34, CD45, and CD56 natural killer cells. Real-time PCR was performed to detect the expression and promoter methylation status of PTEN and MGMT genes. The expression of CSCs markers was found in all GBM cases, and a statistically significant correlation was found among them after co-culture studies. The most pronounced affinity of DCs to GBM cells was observed at dilutions between 1/4 and 1/256 in co-cultures. There was a statistically significant correlation between cellularity and granularity ratios for CD123 and CD11c. PTEN and MGMT gene expression and methylation values were evaluated with respect to CSCs expression and no statistical significance was found. Activation of DCs might associate with CSCs and the mononuclear cells cocktail including CD34, CD45, and CD56 cells which were obtained from allogenic UCB.

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

    PubMed

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

    2007-09-01

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

  10. In Vivo Non Invasive Molecular Imaging for Immune Cell Tracking in Small Animals

    PubMed Central

    Hong, Kee-Jong

    2012-01-01

    Clinical and preclinical in vivo immune cell imaging approaches have been used to study immune cell proliferation, apoptosis and interaction at the microscopic (intra-vital imaging) and macroscopic (whole-body imaging) level by use of ex vivo or in vivo labeling method. A series of imaging techniques ranging from non-radiation based techniques such as optical imaging, MRI, and ultrasound to radiation based CT/nuclear imaging can be used for in vivo immune cell tracking. These imaging modalities highlight the intrinsic behavior of different immune cell populations in physiological context. Fluorescent, radioactive or paramagnetic probes can be used in direct labeling protocols to monitor the specific cell population. Reporter genes can also be used for genetic, indirect labeling protocols to track the fate of a given cell subpopulation in vivo. In this review, we summarized several methods dealing with dendritic cell, macrophage, and T lymphocyte specifically labeled for different macroscopic wholebody imaging techniques both for the study of their physiological function and in the context of immunotherapy to exploit imaging-derived information and immune-based treatments. PMID:23396713

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

    PubMed

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

    1997-04-01

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

  12. 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

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

    PubMed

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

    2017-04-15

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

  14. Tolerogenic IDO+ Dendritic Cells Are Induced by PD-1-Expressing Mast Cells

    PubMed Central

    Rodrigues, Cecilia Pessoa; Ferreira, Ana Carolina Franco; Pinho, Mariana Pereira; de Moraes, Cristiano Jacob; Bergami-Santos, Patrícia Cruz; Barbuto, José Alexandre Marzagão

    2016-01-01

    Mast cells (MCs) are tissue resident cells, rich in inflammatory mediators, involved in allergic reactions, and with an increasingly recognized role in immunomodulation. Dendritic cells (DCs), on the other hand, are central to the determination of immune response patterns, being highly efficient antigen-presenting cells that respond promptly to changes in their microenvironment. Here, we show that direct cell contact between immature monocyte-derived DCs (iDCs) and MC bends DCs toward tolerance induction. DCs that had direct contact with MC (MC-iDC) decreased HLA-DR but increased PD-L1 expression and stimulated regulatory T lymphocytes, which expresses FoxP3+, secrete TGF-β and IL-10, and suppress the proliferation of mitogen-stimulated naïve T lymphocytes. Furthermore, MC-iDC expressed higher levels of indoleamine-2,3-deoxigenase (IDO), a phenomenon that was blocked by treatment of MC with anti-PD-1 or by the treatment of DCs with anti-PD-L1 or anti-PD-L2, but not by blocking of H1 and H2 histamine receptors on DCs. Contact with MC also increased phosphorylated STAT-3 levels in iDCs. When a STAT-3 inhibitor, JSI-124, was added to the DCs before contact with MC, the MC-iDC recovered their ability to induce allogeneic T cell proliferation and did not increase their IDO expression. PMID:26834749

  15. Antitumor efficacy of radiation plus immunotherapy depends upon dendritic cell activation of effector CDS+ T cells

    PubMed Central

    Dovedi, Simon J.; Lipowska-Bhalla, Grazyna; Beers, Stephen A.; Cheadle, Eleanor J.; Mu, Lijun; Glennie, Martin J.

    2017-01-01

    Tumor cells dying after cytotoxic therapy are a potential source of antigen for T-cell priming. Antigen-presenting cells (APCs) can cross-present MHC I–restricted peptides after the uptake of dying cells. Depending on the nature of the surrounding environmental signals, APCs then orchestrate a spectrum of responses ranging from immune activation to inhibition. Previously, we had demonstrated that combining radiation with either agonistic monoclonal antibody (mAb) to CD40 or a systemically administered TLR7 agonist could enhance CD8 T-cell–dependent protection against syngeneic murine lymphoma models. However, it remains unknown how individual APC populations impact on this antitumor immune response. Using APC depletion models, we now show that dendritic cells (DCs), but not macrophages or B cells, were responsible for the generation of long-term immunological protection following combination therapy with radiotherapy and either agonistic CD40 mAb or systemic TLR7 agonist therapy. Novel immunotherapeutic approaches that augment antigen uptake and presentation by DCs may further enhance the generation of therapeutic antitumor immune responses, leading to improved outcomes after radiotherapy. PMID:27241845

  16. Avoiding horror autotoxicus: the importance of dendritic cells in peripheral T cell tolerance.

    PubMed

    Steinman, Ralph Marvin; Nussenzweig, Michel C

    2002-01-08

    The immune system generally avoids horror autotoxicus or autoimmunity, an attack against the body's own constituents. This avoidance requires that self-reactive T cells be actively silenced or tolerized. We propose that dendritic cells (DCs) play a critical role in establishing tolerance, especially in the periphery, after functioning T cells have been produced in the thymus. In the steady state, meaning in the absence of acute infection and inflammation, DCs are in an immature state and not fully differentiated to carry out their known roles as inducers of immunity. Nevertheless, immature DCs continuously circulate through tissues and into lymphoid organs, capturing self antigens as well as innocuous environmental proteins. Recent experiments have provided direct evidence that antigen-loaded immature DCs silence T cells either by deleting them or by expanding regulatory T cells. This capacity of DCs to induce peripheral tolerance can work in two opposing ways in the context of infection. In acute infection, a beneficial effect should occur. The immune system would overcome the risk of developing autoimmunity and chronic inflammation if, before infection, tolerance were induced to innocuous environmental proteins as well as self antigens captured from dying infected cells. For chronic or persistent pathogens, a second but dire potential could take place. Continuous presentation of a pathogen by immature DCs, HIV-1 for example, may lead to tolerance and active evasion of protective immunity. The function of DCs in defining immunologic self provides a new focus for the study of autoimmunity and chronic immune-based diseases.

  17. Human BDCA2+CD123+CD56+ dendritic cells (DCs) related to blastic plasmacytoid dendritic cell neoplasm represent a unique myeloid DC subset.

    PubMed

    Yu, Haisheng; Zhang, Peng; Yin, Xiangyun; Yin, Zhao; Shi, Quanxing; Cui, Ya; Liu, Guanyuan; Wang, Shouli; Piccaluga, Pier Paolo; Jiang, Taijiao; Zhang, Liguo

    2015-04-01

    Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive secretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56(+) DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56(+) DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56(+) DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naïve T cells without prior activation. These data suggest that the CD56(+) DCs represent a novel mDC subset mixed with some pDC features. A CD4(+)CD56(+) hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs. However, we demonstrated that BPDCN is closer to CD56(+) DCs than pDCs by global gene-expression profiling. Thus, we propose that the CD4(+)CD56(+) neoplasm may be a tumor counterpart of CD56(+) mDCs but not pDCs.

  18. Impaired NK Cell Activation and Chemotaxis toward Dendritic Cells Exposed to Complement-Opsonized HIV-1.

    PubMed

    Ellegård, Rada; Crisci, Elisa; Andersson, Jonas; Shankar, Esaki M; Nyström, Sofia; Hinkula, Jorma; Larsson, Marie

    2015-08-15

    Mucosa resident dendritic cells (DCs) may represent one of the first immune cells that HIV-1 encounters during sexual transmission. The virions in body fluids can be opsonized with complement factors because of HIV-mediated triggering of the complement cascade, and this appears to influence numerous aspects of the immune defense targeting the virus. One key attribute of host defense is the ability to attract immune cells to the site of infection. In this study, we investigated whether the opsonization of HIV with complement (C-HIV) or a mixture of complement and Abs (CI-HIV) affected the cytokine and chemokine responses generated by DCs, as well as their ability to attract other immune cells. We found that the expression levels of CXCL8, CXCL10, CCL3, and CCL17 were lowered after exposure to either C-HIV or CI-HIV relative to free HIV (F-HIV). DCs exposed to F-HIV induced higher cell migration, consisting mainly of NK cells, compared with opsonized virus, and the chemotaxis of NK cells was dependent on CCL3 and CXCL10. NK cell exposure to supernatants derived from HIV-exposed DCs showed that F-HIV induced phenotypic activation (e.g., increased levels of TIM3, CD69, and CD25) and effector function (e.g., production of IFNγ and killing of target cells) in NK cells, whereas C-HIV and CI-HIV did not. The impairment of NK cell recruitment by DCs exposed to complement-opsonized HIV and the lack of NK activation may contribute to the failure of innate immune responses to control HIV at the site of initial mucosa infection.

  19. An Automated Pipeline for Dendrite Spine Detection and Tracking of 3D Optical Microscopy Neuron Images of In Vivo Mouse Models

    PubMed Central

    Fan, Jing; Zhou, Xiaobo; Dy, Jennifer G.; Zhang, Yong; Wong, Stephen T. C.

    2009-01-01

    The variations in dendritic branch morphology and spine density provide insightful information about the brain function and possible treatment to neurodegenerative disease, for example investigating structural plasticity during the course of Alzheimer's disease. Most automated image processing methods aiming at analyzing these problems are developed for in vitro data. However, in vivo neuron images provide real time information and direct observation of the dynamics of a disease process in a live animal model. This paper presents an automated approach for detecting spines and tracking spine evolution over time with in vivo image data in an animal model of Alzheimer's disease. We propose an automated pipeline starting with curvilinear structure detection to determine the medial axis of the dendritic backbone and spines connected to the backbone. We, then, propose the adaptive local binary fitting (aLBF) energy level set model to accurately locate the boundary of dendritic structures using the central line of curvilinear structure as initialization. To track the growth or loss of spines, we present a maximum likelihood based technique to find the graph homomorphism between two image graph structures at different time points. We employ dynamic programming to search for the optimum solution. The pipeline enables us to extract dynamically changing information from real time in vivo data. We validate our proposed approach by comparing with manual results generated by neurologists. In addition, we discuss the performance of 3D based segmentation and conclude that our method is more accurate in identifying weak spines. Experiments show that our approach can quickly and accurately detect and quantify spines of in vivo neuron images and is able to identify spine elimination and formation. PMID:19434521

  20. Multistage T cell-dendritic cell interactions control optimal CD4 T cell activation through the ADAP-SKAP55-signaling module.

    PubMed

    Mitchell, Jason S; Burbach, Brandon J; Srivastava, Rupa; Fife, Brian T; Shimizu, Yoji

    2013-09-01

    The Ag-specific interactions between T cells and dendritic cells progress through dynamic contact stages in vivo consisting of early long-term stable contacts and later confined, yet motile, short-lived contacts. The signaling pathways that control in vivo interaction dynamics between T cells and dendritic cells during priming remain undefined. Adhesion and degranulation promoting adapter protein (ADAP) is a multifunctional adapter that regulates "inside-out" signaling from the TCR to integrins. Using two-photon microscopy, we demonstrate that, in the absence of ADAP, CD4 T cells make fewer early-stage stable contacts with Ag-laden dendritic cells, and the interactions are characterized by brief repetitive contacts. Furthermore, ADAP-deficient T cells show reduced contacts at the late motile contact phase and display less confinement around dendritic cells. The altered T cell interaction dynamics in the absence of ADAP are associated with defective early proliferation and attenuated TCR signaling in vivo. Regulation of multistage contact behaviors and optimal T cell signaling involves the interaction of ADAP with the adapter src kinase-associated phosphoprotein of 55 kDa (SKAP55). Thus, integrin activation by the ADAP-SKAP55-signaling module controls the stability and duration of T cell-dendritic cell contacts during the progressive phases necessary for optimal T cell activation.

  1. Development of dendritic web continuous ribbon silicon cells for use in a linear Fresnel lens photovoltaic concentrator

    SciTech Connect

    O'Neill, M.J.; McDanal, A.J.

    1986-04-01

    The primary objective of this program was to design, develop, and test low-cost, continuous ribbon silicon cells suitable for use in ENTECH's linear Fresnel lens photovoltaic concenrator module. The cells were made by Westinghouse using a dendritic web continuous ribbon process. This program represented the first attempt to adapt dendritic web cell fabrication technology to concentrator applications. ENTECH generated an optimized cell design, which included variable metallization matched to the radiant flux profile of the linear Fresnel lens concentrator. Westinghouse fabricated cells in several sequential production runs. The cells were tested by ENTECH under actual lens illumination to determine their performance parameters. The best cells made under this program achieved peak cell efficiencies of about 14%, compared to about 16% for production cells made by Applied Solar Energy Corporation, using float-zone-refined single-crystal silicon. With additional development, significant performance improvements should be achievable in future dendritic web concentrator cells.

  2. S100 protein positive dendritic cells in primary biliary cirrhosis and other chronic inflammatory liver diseases. Relevance to pathogenesis?

    PubMed Central

    Demetris, A. J.; Sever, C.; Kakizoe, S.; Oguma, S.; Starzl, T. E.; Jaffe, R.

    1989-01-01

    A study to determine the location of dendritic cells, in chronic inflammatory liver disease was performed. S100 protein positivity and dendritic cytoplasmic morphology were used to identify dendritic cells. S100 protein positive dendritic cells (S100 + DC) were found inside the basement membrane between biliary epithelial cells of septal bile ducts of livers affected by early stage PBC, but were not present at later stages. S100 + DC also were seen in areas of piecemeal necrosis in chronic active hepatitis of various etiologies. In contrast, intra-epithelial S100 + DC were not found with any consistency in sclerosing cholangitis, secondary biliary cirrhosis, extrahepatic biliary atresia, or chronic liver allograft rejection, all of which are characterized by inflammatory bile duct damage. The possible relevance of DC in the pathogenesis of PBC is discussed. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2705505

  3. Monocyte cell surface glycosaminoglycans positively modulate IL-4-induced differentiation toward dendritic cells.

    PubMed

    den Dekker, Els; Grefte, Sander; Huijs, Tonnie; ten Dam, Gerdy B; Versteeg, Elly M M; van den Berk, Lieke C J; Bladergroen, Bellinda A; van Kuppevelt, Toin H; Figdor, Carl G; Torensma, Ruurd

    2008-03-15

    IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expression of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), CD80, CD206, and CD1a. Monocytes stained positive with Abs against heparan sulfate (HS) and chondroitin sulfate (CS) B (CSB; dermatan sulfate), but not with Abs that recognize CSA, CSC, and CSE. Inhibition of sulfation of monocyte/DC cell surface GAGs by sodium chlorate reduced the reactivity of sulfate-recognizing single-chain Abs. This correlated with hampered IL-4-induced DC differentiation as evidenced by lower expression of DC-SIGN and CD1a and a decreased DC-induced PBL proliferation, suggesting that sulfated monocyte cell surface GAGs support IL-4 activity. Furthermore, removal of cell surface chondroitin sulfates by chondroitinase ABC strongly impaired IL-4-induced STAT6 phosphorylation, whereas removal of HS by heparinase III had only a weak inhibitory effect. IL-4 bound to heparin and CSB, but not to HS, CSA, CSC, CSD, and CSE. Binding of IL-4 required iduronic acid, an N-sulfate group (heparin) and specific O sulfates (CSB and heparin). Together, these data demonstrate that monocyte cell surface chondroitin sulfates play an important role in the IL-4-driven differentiation of monocytes into DCs.

  4. 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

  5. IL-32γ induces chemotaxis of activated T cells via dendritic cell-derived CCL5.

    PubMed

    Son, Mi Hye; Jung, Mi Young; Choi, Seulah; Cho, Daeho; Kim, Tae Sung

    2014-07-18

    Interleukin (IL)-32 has been associated with a variety of inflammatory diseases including rheumatoid arthritis, vasculitis and Crohn's disease. We have previously reported that IL-32γ, the IL-32 isoform with the highest biological activity, could act as an immune modulator through regulation of dendritic cell (DC) functions in immune responses. Cell locomotion is crucial for induction of an effective immune response. In this study, we investigated the effect and underlying mechanisms of IL-32γ on recruitment of T cells. IL-32γ upregulated the expression of several chemokines including CCL2, CCL4, and CCL5 in the DCs. In particular, IL-32γ significantly increased CCL5 expression in a dose-dependent manner. Treatment with JNK and NF-κB inhibitors suppressed IL-32γ-induced CCL5 expression in DCs, indicating that IL-32γ induced CCL5 production through the JNK and NF-κB pathways. Furthermore, supernatants from IL-32γ-treated DCs showed chemotactic activities controlling migration of activated CD4(+) and CD8(+) T cells, and these activities were suppressed by addition of neutralizing anti-CCL5 antibody. These results show that IL-32γ effectively promotes migration of activated T cells via CCL5 production in DCs. The chemotactic potential of IL-32γ may explain the pro-inflammatory effects of IL-32 and the pathologic role of IL-32 in immune disorders such as rheumatoid arthritis.

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

    PubMed

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

    2013-01-01

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

  7. Glycan modification of antigen alters its intracellular routing in dendritic cells, promoting priming of T cells

    PubMed Central

    Streng-Ouwehand, Ingeborg; Ho, Nataschja I; Litjens, Manja; Kalay, Hakan; Boks, Martine Annemarie; Cornelissen, Lenneke AM; Kaur Singh, Satwinder; Saeland, Eirikur; Garcia-Vallejo, Juan J; Ossendorp, Ferry A; Unger, Wendy WJ; van Kooyk, Yvette

    2016-01-01

    Antigen uptake by dendritic cells and intracellular routing of antigens to specific compartments is regulated by C-type lectin receptors that recognize glycan structures. We show that the modification of Ovalbumin (OVA) with the glycan-structure LewisX (LeX) re-directs OVA to the C-type lectin receptor MGL1. LeX-modification of OVA favored Th1 skewing of CD4+ T cells and enhanced cross-priming of CD8+ T cells. While cross-presentation of native OVA requires high antigen dose and TLR stimuli, LeX modification reduces the required amount 100-fold and obviates its dependence on TLR signaling. The OVA-LeX-induced enhancement of T cell cross-priming is MGL1-dependent as shown by reduced CD8+ effector T cell frequencies in MGL1-deficient mice. Moreover, MGL1-mediated cross-presentation of OVA-LeX neither required TAP-transporters nor Cathepsin-S and was still observed after prolonged intracellular storage of antigen in Rab11+LAMP1+ compartments. We conclude that controlled neo-glycosylation of antigens can crucially influence intracellular routing of antigens, the nature and strength of immune responses and should be considered for optimizing current vaccination strategies. DOI: http://dx.doi.org/10.7554/eLife.11765.001 PMID:26999763

  8. Antigenically Modified Human Pluripotent Stem Cells Generate Antigen-Presenting Dendritic Cells

    PubMed Central

    Zeng, Jieming; Wu, Chunxiao; Wang, Shu

    2015-01-01

    Human pluripotent stem cells (hPSCs) provide a promising platform to produce dendritic cell (DC) vaccine. To streamline the production process, we investigated a unique antigen-loading strategy that suits this novel platform. Specifically, we stably modified hPSCs using tumour antigen genes in the form of a full-length tumour antigen gene or an artificial tumour antigen epitope-coding minigene. Such antigenically modified hPSCs were able to differentiate into tumour antigen-presenting DCs. Without conventional antigen-loading, DCs derived from the minigene-modified hPSCs were ready to prime a tumour antigen-specific T cell response and further expand these specific T cells in restimulation processes. These expanded tumour antigen-specific T cells were potent effectors with central memory or effector memory phenotype. Thus, we demonstrated that immunocompetent tumour antigen-loaded DCs can be directly generated from antigenically modified hPSCs. Using such strategy, we can completely eliminate the conventional antigen-loading step and significantly simplify the production of DC vaccine from hPSCs. PMID:26471005

  9. Targeting dendritic cells to accelerate T-cell activation overcomes a bottleneck in tuberculosis vaccine efficacy

    PubMed Central

    Griffiths, Kristin L.; Ahmed, Mushtaq; Das, Shibali; Gopal, Radha; Horne, William; Connell, Terry D.; Moynihan, Kelly D.; Kolls, Jay K.; Irvine, Darrell J.; Artyomov, Maxim N.; Rangel-Moreno, Javier; Khader, Shabaana A.

    2016-01-01

    The development of a tuberculosis (TB) vaccine that induces sterilizing immunity to Mycobacterium tuberculosis infection has been elusive. Absence of sterilizing immunity induced by TB vaccines may be due to delayed activation of mucosal dendritic cells (DCs), and subsequent delay in antigen presentation and activation of vaccine-induced CD4+ T-cell responses. Here we show that pulmonary delivery of activated M. tuberculosis antigen-primed DCs into vaccinated mice, at the time of M. tuberculosis exposure, can overcome the delay in accumulation of vaccine-induced CD4+ T-cell responses. In addition, activating endogenous host CD103+ DCs and the CD40–CD40L pathway can similarly induce rapid accumulation of vaccine-induced lung CD4+ T-cell responses and limit early M. tuberculosis growth. Thus, our study provides proof of concept that targeting mucosal DCs can accelerate vaccine-induced T-cell responses on M. tuberculosis infection, and provide insights to overcome bottlenecks in TB vaccine efficacy. PMID:28004802

  10. Proteomic analysis of dendritic cell-derived exosomes: a secreted subcellular compartment distinct from apoptotic vesicles.

    PubMed

    Théry, C; Boussac, M; Véron, P; Ricciardi-Castagnoli, P; Raposo, G; Garin, J; Amigorena, S

    2001-06-15

    Dendritic cells constitutively secrete a population of small (50-90 nm diameter) Ag-presenting vesicles called exosomes. When sensitized with tumor antigenic peptides, dendritic cells produce exosomes, which stimulate anti-tumor immune responses and the rejection of established tumors in mice. Using a systematic proteomic approach, we establish the first extensive protein map of a particular exosome population; 21 new exosomal proteins were thus identified. Most proteins present in exosomes are related to endocytic compartments. New exosomal residents include cytosolic proteins most likely involved in exosome biogenesis and function, mainly cytoskeleton-related (cofilin, profilin I, and elongation factor 1alpha) and intracellular membrane transport and signaling factors (such as several annexins, rab 7 and 11, rap1B, and syntenin). Importantly, we also identified a novel category of exosomal proteins related to apoptosis: thioredoxin peroxidase II, Alix, 14-3-3, and galectin-3. These findings led us to analyze possible stru