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Immature DC (immature + dc)
Selected AbstractsDetection of fascin and CCR-7 positive mature dendritic cells in oral lichen planusJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 4 2009Shotaro Mukae Background:, Dendritic cells (DC) play a crucial role in the pathogenesis of oral lichen planus (OLP) with respect to antigens presented to T cells. We performed immunohistochemical analysis to elucidate the process of activation of DC in OLP. Methods:, Thirty biopsy specimens were obtained from the patients with OLP. The expressions of CD1a, Langerin, S-100, fascin, chemokine receptor-7 (CCR-7), D2-40, cyclooxygenase-2 (COX-2), and microsomal prostaglandin E synthase-1 (mPGES-1) in DC from OLP and disease free control were investigated using specific antibodies. The distribution and number (1 mm2) of DC were assessed in the intra-epithelium and the submucosa specimens. Correlation between the number of DC and epithelium thickness was also determined. Result:, Immature DC (Langerin+, CD1a+, and S-100+) were identified in the epithelia from OLP patients and control, though the numbers of Langerin+ and CD1a+ positive cells were decreased in the OLP samples as compared to the control. Mature DC (fascin+) were identified in the submucosa specimens, not found in the epithelium from OLP or control. Double immunostaining revealed DC positive for fascin and CCR-7 in the submucosa, which had migrated into D2-40+ lymph vessels. Furthermore, keratinocytes expressed both Prostaglandin E2 (PGE2) converting enzymes, COX-2, and mPGES-1, indicating PGE2 synthesis in the epithelial layer of the OLP specimens. Conclusion:, Our results indicate that DC change from immature to mature in the epithelium and are then drawn out to the submucosa. We demonstrate that mature DC localized in the submucosa, it consequently migrates into lymph vessels. This maturation process of DC is an important immunopathological feature of OLP. [source] Hericium erinaceum induces maturation of dendritic cells derived from human peripheral blood monocytesPHYTOTHERAPY RESEARCH, Issue 1 2010Sun Kyung Kim Abstract Hericium erinaceum, a medicinal mushroom, has long been used as a therapeutic due to its immuno-regulating potentials eliciting anticarcinogenic and antimicrobial efficacies. Since maturation of dendritic cells (DC) is an important process in the initiation and regulation of immune responses, the ability of water-soluble components from H. erinaceum (WEHE) to regulate DC maturation was investigated. Immature DC were prepared by differentiating human peripheral blood CD14-positive cells with GM-CSF and IL-4. DC were stimulated with WEHE at 2,20 µg/mL for 48 h and subjected to flow cytometric analysis to determine the expression of indicative maturation markers. The endocytic capacity of WEHE-stimulated DC was examined by a Dextran-FITC uptake assay. An enzyme-linked immunosorbent assay was performed to examine the secretion of TNF- , and IL-12p40. DC stimulated with WEHE showed representative features upon DC maturation: enhanced expression of CD80, CD83 and CD86, and both MHC class I and II molecules, decreased endocytic capacity of DC, increased expression of CD205, and decreased expression of CD206. However, interestingly, WEHE could not induce the production of TNF- , and IL-12p40, whereas lipopolysaccharide substantially increased the production of both cytokines. Collectively, these results suggest that H. erinaceum induces the maturation of human DC, which might reinforce the host innate immune system. Copyright © 2009 John Wiley & Sons, Ltd. [source] Pulmonary stromal cells induce the generation of regulatory DC attenuating T-cell-mediated lung inflammationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2008Qian Li Abstract The tissue microenvironment may affect the development and function of immune cells such as DC. Whether and how the pulmonary stromal microenvironment can affect the development and function of lung DC need to be investigated. Regulatory DC (DCreg) can regulate T-cell response. We wondered whether such regulatory DC exist in the lung and what is the effect of the pulmonary stromal microenvironment on the generation of DCreg. Here we demonstrate that murine pulmonary stromal cells can drive immature DC, which are regarded as being widely distributed in the lung, to proliferate and differentiate into a distinct subset of DCreg, which express high levels of CD11b but low levels of MHC class II (I-A), CD11c, secrete high amounts of IL-10, NO and prostaglandin E2 (PGE2) and suppress T-cell proliferation. The natural counterpart of DCreg in the lung with similar phenotype and regulatory function has been identified. Pulmonary stroma-derived TGF-, is responsible for the differentiation of immature DC to DCreg, and DCreg-derived PGE2 contributes to their suppression of T-cell proliferation. Moreover, DCreg can induce the generation of CD4+CD25+Foxp3+ Treg. Importantly, infusion with DCreg attenuates T-cell-mediated eosinophilic airway inflammation in vivo. Therefore, the pulmonary microenvironment may drive the generation of DCreg, thus contributing to the maintenance of immune homoeostasis and the control of inflammation in the lung. [source] Dendritic cells: Understanding immunogenicityEUROPEAN JOURNAL OF IMMUNOLOGY, Issue S1 2007Ralph Abstract The impetus for the discovery of dendritic cells in 1972 was to understand immunogenicity, the capacity of an antigenic substance to provoke immunity. During experiments to characterize "accessory" cells that enhanced immunity, we spotted unusual stellate cells in mouse spleen. They had a distinct capacity to form and retract processes or dendrites and were named dendritic cells (DC). DC proved to be different from other cell types and to be peculiarly immunogenic when loaded with antigens. When Langerhans cells were studied, immunogenicity was found to involve two steps: antigen presentation by immature DC and maturation to elicit immunity. Antigen-bearing DC were also immunogenic in vivo and were therefore termed "nature's adjuvants". Several labs then learned to generate large numbers of DC from progenitors, which accelerated DC research. Tolerogenicity via DC, including the control of foxp3+ suppressor T cells, was recently discovered. Two areas of current research that I find intriguing are to identify mechanisms for antigen uptake and processing, and for the control of different types of immunity and tolerance. These subjects should be studied in vivo with clinically relevant antigens, so that the activities of DC can be better integrated into the prevention and treatment of disease in patients. [source] Vaccinia virus impairs directional migration and chemokine receptor switch of human dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2007Abstract A crucial event for the induction of an anti-viral immune response is the coordinated, phenotype-dependent migration of dendritic cells (DC) to sites of infection and secondary lymphoid organs. Here we show that the vaccinia virus (VV) strains Western Reserve (WR) and modified virus Ankara (MVA) inhibit directional migration of mature DC toward the lymphoid chemokines CCL19 and CXCL12 without affecting surface expression of the respective chemokine receptors or impairing undirected cellular locomotion. Instead, infection with VV results in a deficiency of extracellular signal-regulated kinase-1 and a disturbance of intracellular calcium mobilization, indicating a viral interference with signaling events downstream of the surface chemokine receptors. In immature DC, apart from inhibiting chemokine-induced migration of infected DC, infection with both VV strains increases expression of the inflammatory chemokine receptors CCR1 and CXCR1 on non-infected bystander DC, which depends on the activity of IFN-,. Although functional, these chemokine receptors are resistant to lipopolysaccharide-induced down-regulation. In addition, VV-infected and non-infected bystander DC fail to up-regulate the lymphoid chemokine receptor CCR7 upon activation, together pointing to a disability to undergo the chemokine receptor switch. This study shows that VV targets directional migration of professional antigen-presenting cells at multiple functional levels, revealing a potent viral strategy of immune escape. See accompanying commentary: http://dx.doi.org/10.1002/eji.200737215 [source] Inhibitory effect of the polyinosinic-polycytidylic acid/cationic liposome on the progression of murine B16F10 melanomaEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2006Taku Fujimura Abstract Cellular proteins, retinoic acid inducible gene-I and Toll-like receptor 3, sense dsRNA including polyinosinic-polycytidylic acid (PIC) to stimulate innate immune response. The local administration of PIC has been demonstrated to be effective in anti-tumor immunotherapy. However, the effects of PIC delivered cross the cell membrane have not yet been examined. To address this issue, we used a complex of PIC and cationic liposome (PIC liposome) and examined its anti-tumor effects in vitro and in vivo. PIC liposome could directly suppress the growth of B16F10 melanoma in vitro and repeated peritumoral injections of PIC liposome inhibited melanoma growth in a dose-dependent manner. This treatment induced tyrosinase-related protein-2 (TRP-2)-tetramer+ CD8+ cells in the lymph nodes. As the mechanism for its anti-tumor immune response, we showed that the intradermal injection of PIC liposome induced the maturation of dendritic cells (DC). Moreover, the intratumoral injection of immature DC after treatment with PIC liposome significantly increased the number of TRP-2-specific IFN-,-producing cells in the lymph nodes as well as spleen, which resulted in an augmentation of the anti-tumor immune response. These studies demonstrate the potential of peritumoral injection of PIC liposome as immunotherapy for malignant melanoma. [source] Interaction between the CCR5 chemokine receptors and microbial HSP70EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 9 2006Trevor Whittall Abstract Evidence is presented that the microbial 70-kD heat shock protein (HSP70) binds to CCR5 chemokine receptors in CCR5-transfected cell lines and in primary human cells. Significant CCR5-mediated calcium mobilization was stimulated by HSP70 and inhibited with TAK,779, which is a specific CCR5 antagonist. HSP70-mediated activation of the p38 MAPK phosphorylation signaling pathway was also demonstrated in CCR5-transfected HEK 293 cells. Direct binding of three extracellular peptides of CCR5 to HSP70 was demonstrated by surface plasmon resonance. Functional evidence of an interaction between HSP70, CCR5 and CD40 was shown by enhanced production of CCL5 by HEK 293 cells transfected with both CD40 and CCR5. Primary monocyte-derived immature DC stimulated with HSP70 produced IL-12 p40, which showed dose-dependent inhibition of >90% on treatment with both TAK 779 and anti-CD40 mAb. Stimulation of IL-12 p40 or TNF-, by HSP70 was related to the differential cell surface expression of CCR5 in primary human immature and mature DC, and those with the homozygous ,,32 CCR5 mutation. These findings may be of significance in the interaction between HSP70 and immune responses of CCR5+ T cells in HIV-1 infection, as well as in inflammatory bowel disease. See accompanying commentary: http://dx.doi.org/10.1002/eji.200636551 [source] The corticosteroid-induced inhibitory effect on NK cell function reflects down-regulation and/or dysfunction of triggering receptors involved in natural cytotoxicityEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 11 2004Chiara Vitale Abstract Corticosteroids are known to inhibit NK cell functions. However no information is available on whether such inhibition may affect the expression and/or the function of receptors involved in NK cell activation. In an attempt to analyze this point, we studied peripheral blood NK cells isolated from pediatric patients undergoing allogeneic BM transplantation. NK cells were analyzed before, during and after methylprednisolone administration to treat acute graft-versus-host disease. In NK cells freshly isolated from peripheral blood during methylprednisolone treatment, the surface expression of activating receptors, particularly NKp46 and NKp30, was consistently reduced. Such impaired expression could also be detected after 5,days of culture in IL-2. Such cultured NK cells also failed to express the IL-2-inducible NKp44 receptor. Accordingly, cytotoxicity against different tumor target cell lines was sharply reduced. The effect on NK cells isolated from healthy individuals and cultured in the presence of methylprednisolone was also analyzed. A similar inhibitory effect occurred in the expression of activating NK receptors. In addition, a sharp impairment of NK cytotoxicity against different tumor target cell lines or immature DC was detected. [source] Expression of milk fat globule epidermal growth factor,8 in immature dendritic cells for engulfment of apoptotic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2004Kay Miyasaka Abstract Milk fat globule epidermal growth factor,8 (MFG-E8) is a protein that stimulates the engulfment of apoptotic cells by phagocytes. Here, we show that mouse immature dendritic cells (DC) generated in vitro by culturing bone marrow progenitors in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), and Langerhans cells present in the skins, expressed MFG-E8. Bone marrow-derived macrophages generated by M-CSF did not express MFG-E8. MFG-E8 expressed in immature DC was found to be secreted as exosomes. The expression of MFG-E8 was significantly suppressed when the immature DC were induced to mature by treating them with lipopolysaccharides. This expression of MFG-E8 was well correlated with the ability of the cells to engulf apoptotic cells. That is,immature DC phagocytosed apoptotic cells more efficiently than did mature DC or bone marrow-derived macrophages. The ability of immature DC to engulf apoptotic cells was severely reduced when the immature DC were prepared from MFG-E8-deficient mice. These results indicated that MFG-E8 plays an essential role in the engulfment of apoptotic cells by bone marrow-derived immature DC. [source] Murine thymic plasmacytoid dendritic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 4 2003Tomoyuki Okada Abstract We report herein heterogeneous murine thymic cell subsets expressing CD11c and B220 (CD45R). The CD11c+B220+ subset expresses Ly6Chigh and MHC class IIlow in contrast with previously described thymic DC (CD11c+B220, cells). Freshly isolated thymic CD11c+B220+ cells show typical plasmacytoid morphology which differentiates to mature DC, in vitro with CpG oligodeoxynucleotides (ODN) 2216; we term this subset thymic plasmacytoid DC (pDC). These thymic pDC are highly sensitive to spontaneous apoptosis in vitro and induce low T cell allo-proliferation activity. Thymic pDC express low TLR2, TLR3 and TLR4 mRNA, normally found on human immature DC, and high TLR7 and TLR9 mRNA, normally found on human pDC. Thymic pDC also produce high amounts of IFN-, following culture with CpG ODN 2216 (TLR9 ligands) as compared with the previously defined thymic DC lineage which expresses low TLR9 mRNA and produce high IL-12 (p40) with CpG ODN 2216. These results indicate that thymic pDC are similar to IFN-producing cells as well as human pDC. The TLR and cytokine production profiles are consistent with a nomenclature of pDC. The repertoire of this cell lineage to TLR9 ligands demonstrate that such responses are determined not only by the quantity of expression, but also cell lineage. [source] Histamine and prostaglandin E2 up-regulate the production of Th2-attracting chemokines (CCL17 and CCL22) and down-regulate IFN-,-induced CXCL10 production by immature human dendritic cellsIMMUNOLOGY, Issue 4 2006Anne McIlroy Summary Effector memory T helper 2 (Th2) cells that accumulate in target organs (i.e. skin or bronchial mucosa) have a central role in the pathogenesis of allergic disorders. To date, the factors that selectively trigger local production of Th2-attracting chemokines remain poorly understood. In mucosa, at the sites of allergen entry, immature dendritic cells (DC) are in close contact with mast cells. Histamine and prostaglandin E2 (PGE2) are two mediators released by allergen-activated mast cells that favour the polarization of maturing DC into Th2-polarizing cells. We analysed here the effects of histamine and PGE2 on the prototypic, Th2-(CCL17, CCL22) versus Th1-(CXCL10) chemokine production by human DC. We report that histamine and PGE2 dose-dependently up-regulate CCL17 and CCL22 by monocyte-derived immature DC. These effects were potentiated by tumour necrosis factor-,, still observed in the presence of the Th1-cytokine interferon-, (IFN-,) and abolished by the immunomodulatory cytokine interleukin-10. In addition, histamine and PGE2 down-regulated IFN-,-induced CXCL10 production by monocyte-derived DC. These properties of histamine and PGE2 were observed at the transcriptional level and were mediated mainly through H2 receptors for histamine and through EP2 and EP4 receptors for PGE2. Finally, histamine and PGE2 also up-regulated CCL17 and CCL22 and decreased IFN-,-induced CXCL10 production by purified human myeloid DC. In conclusion, these data show that, in addition to polarizing DC into mature cells that promote naïve T-cell differentiation into Th2 cells, histamine and PGE2 may act on immature DC to trigger local Th2 cell recruitment through a selective control of Th1/Th2-attracting chemokine production, thereby contributing to maintain a microenvironment favourable to persistent immunoglobulin E synthesis. [source] Expression of ,-defensin 1 and 2 mRNA by human monocytes, macrophages and dendritic cellsIMMUNOLOGY, Issue 4 2002Louise A. Duits Summary Human ,-defensins are broad-spectrum antimicrobial peptides known to be produced by epithelial cells. It was recently shown that ,-defensins also display chemotactic activity for dendritic cells (DC) and T cells, and thus may serve to link innate and adaptive immunity. The aim of the present study was to explore expression of mRNA for these peptides in mononuclear phagocytes and DC. The results revealed that monocytes, monocyte-derived-macrophages (MDM), and monocyte-derived-dendritic cells (DC) all express human-,-defensin-1 (hBD-1) mRNA. hBD-1 mRNA expression by monocytes and MDM was increased after activation with interferon-, (IFN-,) and/or lipopolysaccharide (LPS) in a dose- and time-dependent fashion. Alveolar macrophages showed an intense hBD-1 expression, which could not be further increased. Expression of hBD-1 mRNA by immature DC was low, and increased considerably after maturation. Monocytes, MDM, alveolar macrophages and DC showed a limited expression of human ,-defensin-2 (hBD-2) mRNA, which could only be increased in monocytes and alveolar macrophages by IFN-, and/or LPS in a dose- and time-dependent fashion. Immunocytochemical stainings demonstrated the expression of hBD-2 peptide by freshly isolated blood monocytes and alveolar macrophages in cytospin preparations. [source] Immunotherapy against metastatic renal cell carcinoma with mature dendritic cellsINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2007Akihiko Matsumoto Objective: We performed a clinical trial of immunotherapy using autologous mature dendritic cells (DC) pulsed with autologous tumor lysate, for patients with metastatic renal cell carcinoma (RCC). Methods: Patients with refractory metastatic RCC were enrolled in the study. All of them received interferon (IFN)-, treatment after nephrectomy and were followed over 3 months prior to this study. Autologous monocyte-derived immature DC were pulsed with lysate from autologous primary tumor as the antigen and keyhole limpet hemocyanin (KLH) as immunomodulator, and cultured in the presence of tumor necrosis factor (TNF)-,, interleukin (IL)-1,, and prostaglandin (PG)E2 to generate mature DC. Mature DC were injected intradermally near bilateral inguinal lymph nodes of the patients. A delayed-type hypersensitivity (DTH) test and enzyme-linked immunospot (ELISPOT) assay were performed to evaluate the immunological response. After 4 months from first injection, the clinical effect was evaluated by diagnostic imaging. Results: The treatments were well tolerated without significant toxicity by the patients who were an average of 65.7 years old and had multiple metastases in the lung and other organs. One of the two patients developed a positive DTH reaction to tumor lysate and the other patient only to KLH. The patient with a positive DTH reaction to tumor lysate had stable disease in the clinical evaluation. Conclusions: We confirmed the safety of DC therapy in this clinical trial. The DTH test revealed that the DC therapy induced immunological response to RCC. On the other hand, it was necessary to reconsider the patient selection criteria. [source] Closed system generation of dendritic cells from a single blood volume for clinical application in immunotherapy,JOURNAL OF CLINICAL APHERESIS, Issue 4 2005M. Elias Dendritic cells (DC) used for clinical trials should be processed on a large scale conforming to current good manufacturing practice (cGMP) guidelines. The aim of this study was to develop a protocol for clinical grade generation of immature DC in a closed-system. Aphereses were performed with the Cobe SpectraÔ continuous flow cell separator and material was derived from one volume of blood processed. Optimisation of a 3-phase collection autoPBSC technique significantly improved the quality of the initial mononuclear cell (MNC) product. Monocytes were then enriched from MNC by immunomagnetic depletion of CD19+ B cells and CD2+ T cells and partial depletion of NK cells using the Isolex 300I Magnetic cell selector. The quality of the initial mononuclear cell product was found to determine the outcome of monocyte enrichment. Enriched monocytes were cultured in Opticyte gas-permeable containers using CellGro serum-free medium supplemented with GM-CSF and IL-4 to generate immature DC. A seeding concentration of 1 × 106 was found optimal in terms of DC phenotype expression, monocyte percentage in culture, and cell viability. The differentiation pattern favours day 7 for harvest of immature DC. DC recovery, viability, as well as phenotype expression after cryopreservation of immature DC was considered in this study. DC were induced to maturation and evaluated in FACS analysis for phenotype expression and proliferation assays. Mature DC were able to generate an allogeneic T-cell response as well as an anti-CMV response as detected by proliferation assays. These data indicate that the described large-scale GMP-compatible system results in the generation of stable DC derived from one volume of blood processed, which are qualitatively and quantitatively sufficient for clinical application in immunotherapeutic protocols. J. Clin. Apheresis © 2005 Wiley-Liss, Inc. [source] Generation of self-renewing immature dendritic cells from mouse spleen that can take up mycobacteria and present antigens to T cellsAPMIS, Issue 10 2010RUBINA PAL Pal R, Marwaha S, Pepponi I, Mann JFS, Paul MJ, Reljic R. Generation of self-renewing immature dendritic cells from mouse spleen that can take up mycobacteria and present antigens to T cells. APMIS 2010; 118: 729,38. Dendritic cells (DC) play a key role in driving the adaptive immune response to Mycobacterium tuberculosis (MTB), the causative pathogen of tuberculosis (TB). However, studying these important yet very sparse immune cells in the context of MTB pathogenesis is severely restricted by the lack of suitable cell lines and the complexity of culturing of DC progenitors, usually obtained from the bone marrow. However, significant advances have been made towards generating long-term DC cultures from various lymphoid tissues. Here, we report the evidence for generating a long-term, self-renewing DC culture from the Balb/c mouse spleen. We demonstrate that these cells, termed IDC-3, have a myeloid DC origin, i.e. they are CD11c+CD11b++CD8-,,F4/80+/, and that they also display a phenotype MHC-II+CD16/32++CD80+/,CD86+, indicating that they are immature DC. Following incubation with Mycobacterium bovis BCG (Bacillus Calmette Guerin), the IDC-3 efficiently took up bacteria and acquired the morphology of mature DC. Importantly though, when IDC-3 were pre-stimulated with a mycobacterial antigen in vitro, they were able to induce proliferation of T lymphocytes from mice immunized with the same antigen. The T-cell stimulatory potential of IDC-3 was further enhanced when the cells were co-stimulated with an anti-CD40 mAb. We therefore suggest that the IDC-3 culture system could be a useful tool for studying the interaction of DC with mycobacteria. [source] | ||||||||||