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Search Results: 1 - 10 of 8924 matches for " dendritic cells "
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HLA-Identical Dendritic-Leukemic Cell Hybrids Generate Specific CTLs in Vitro  [PDF]
Rinat Eshel, Meirav Shpringer, Nadia Voskobinik, Akiva Vexler, Rami Ben-Yosef, Inna Fabian, Boris Tartakovsky, Elizabeth Naparstek
Journal of Cancer Therapy (JCT) , 2010, DOI: 10.4236/jct.2010.13023
Abstract: hile being instrumental in the treatment of leukemic relapse after allogeneic hematopoietic stem cell transplantation, the impact of donor lymphocyte infusion (DLI) and its effectiveness remain debatable. Consequently it is widely accepted that more efforts are needed in order to make DLI more effective. This communication thus deals with the generation of specific CTLs in the clinical setting of HLA matched hematopoietic stem cell transplantation, to be used as an improved DLI treatment for post-transplantation relapsed leukemias. We assessed the potential of fused dendritic cells from donor origin, with leukemic cells from the HLA matched recipient for the generation of donor anti-tumor CTLs. Leukemic cells and donor dendritic cells were fused using polyethylene glycol (PEG). The hybrids were analyzed for double phenotype of both DC and tumor, and used for the education and generation of cytotoxic donor lymphocytes. Results demonstrate that efficient and specific CTLs can be generated and used in vitro for the elimination of the recipient tumor cells. These results form the basis for the establishment of a novel methodology aimed at generating active or passive anti-leukemic vaccine in relapsed patients.
The Effect of Granulocyte Macrophage-Colony Stimulating Factor upon the Induction of Peripheral Blood Dendritic and Natural Killer Cells When Given Simultaneously with a Slow Continuous Doxorubicin Infusion  [PDF]
Arthur J. Weiss, Irwin L. Stoloff, Antonio C. Simoes
Journal of Cancer Therapy (JCT) , 2017, DOI: 10.4236/jct.2017.87054
Abstract: It has been demonstrated that it is safe to give Gm-Csf, together with Doxorubicin, by continuous intravenous infusion, thereby substantially increasing the amount of Doxorubicin administered to the average patient, and assuring that each patient receives an individually-determined safe and maximal amount of drug. It is known that Gm-Csf is a potent inducer of components that are major factors in an immunologic attack upon neoplasms. For that reason, we thought it would be worth evaluating in 4 patients’ surface markers of dendritic precursor cells, dendritic cells [DC], and natural killer [NK] cells during the infusion. While there was substantial variation in individual responses, all 4 patients receiving Gm-Csf developed persistent marked increases in cells with each of these markers. The significance of these findings will be discussed.
In vitro analysis of T cell responses induced by breast tumor cell lysate pulsed with autologous dendritic cells  [PDF]
Nowruz Delirezh, Seyed Mohammad Moazzeni, Fazel Shokri, Mohammad Ali Shokrgozar, Morteza Morteza Atri, Hamid Karbassian
Advances in Bioscience and Biotechnology (ABB) , 2012, DOI: 10.4236/abb.2012.32019
Abstract: In this In vitro study, T cell responses induced by breast tumor cell lysate pulsed monocyte-derived DCs were analyzed in terms of proliferation, specific cytotoxicity and cytokine-release in order to use in immunotherapeutic settings. Nylon wool enriched T lymphocytes from 5 patients with breast cancer stimulated In vitro with tumor cell lysate pulsed monocyte-derived DCs and their proliferation response were analyzed by [3H] thymidine uptake test. Specific cytotoxic activity of tumor antigen primed T cells after three rounds weekly stimulation was evaluated by flow cytometry, and interferon-γ (IFN-γ) and interleukin-4 (IL-4) cytokines release assay was carried out 24 hours after last stimulation in the supernatant of primed T cells using commercially available ELI-SA kits. T cell proliferation assay revealed that tumor cell lysate pulsed DCs could stimulate autologous T cell proliferation response with stimulation indices 4.9 - 30. T cell mediated cytotoxicity assay demonstrated that tumor antigen primed T cells could significantly kill autologous tumor cells more than normal cells (P < 0.05). These cells had variable amounts of cytotoxic activity against K562 cells as well. Primed T cells were released both IFN-γ and IL-4 in response to restimulation by antigen pulsed DCs which were dominated by IFN-γ production in 2 and IL-4 production in 3 out of 5 patients. Our result suggested that breast tumor antigen pulsed DCs could elicit effective specific antitumor T cell responses In vitro, therefore, tumor antigen pulsed DC vaccination may be considered as a novel strategy for immunotherapy of patients with breast cancer refractory to standard modalities.
Clinical and Immunological Effects in Patients with Advanced Non-Small Cell Lung-Cancer after Vaccination with Dendritic Cells Exposed to an Allogeneic Tumor Cell Lysate  [PDF]
Lotte Engell-Noerregaard, Pia Kvistborg, Mai-Britt Zocca, Ayako W. Pedersen, Mogens H. Claesson, Anders Mellemgaard
World Journal of Vaccines (WJV) , 2013, DOI: 10.4236/wjv.2013.32011
Abstract:

Background: We evaluated the clinical and immunological effects of dendritic cell (DC) vaccination of patients with NSCLC. Autologous DCs were pulsed with a MAGE containing allogeneic melanoma cell lysate (MelCancerVac?, Dandrit Biotech,Copenhagen,Denmark). Imiquimod cream, proleukin and celecoxib were used as adjuvants to the vaccines. The objective of the study was to evaluate specific T cell response in vitro by IFNg EliSpot. Secondary objectives were overall survival, response and quality of life (QoL). Results: Twenty-two patients initiated the vaccination program consisting of ten vaccinations. Seven patients remained in stable disease (SD) three months after the first vaccination. After ten vaccinations (six months), four patients still showed SD and continued vaccinations on a monthly basis. These four patients received a total of 12, 16, 26 and 35 vaccinations, respectively. Five patients showed an unexpectedly prolonged survival. The treatment was well tolerated and only minor adverse events were reported. Quality of life did not change during the study period. In four of the seven patients with SD, vaccine-specific T cells were detected by IFNγ EliSpot assays, whereas only one patient with progressive disease (PD) showed vaccine-specific responses. Conclusion: This DC-based vaccine trial has indicated a correlation between vaccine-specific immunity and sustained SD. Furthermore, we observed an unexpectedly prolonged survival in some patients, which may indicate delayed effect of DC vaccination after completion of the treatment. A prospective randomized phase-IIb or -III is needed to further evaluate the use of MelCancerVac? vaccine treatment in patients with progressive NSCLC.

Seasonal modulation of the C-type lectin MGL on human DCs  [PDF]
Ilaria Grazia Zizzari, Chiara Napoletano, Aurelia Rughetti, Hassan Rahimi, Marianna Nuti
Open Journal of Immunology (OJI) , 2013, DOI: 10.4236/oji.2013.34027
Abstract: The C-type lectin MGL is a pathogen recognition receptor, expressed by dendritic cells (DCs) and macrophages (Mfs), able to bind GalNAc (Tn) carrying structures. This receptor also recognized Tn-TAAs that were internalized, processed and presented by DCs to T cells and it acted as an adjuvant on DCs, highlighting its possible application in anti-cancer vaccination. In this work, we found that this receptor present a seasonal modulation: its expression is higher in winter rather than in summer. The percentage of MGL+ donors displayed a negative trend that dropped to 33% during the summer and increased up to 100% in winter. This modulation could be also ascribed to the circa-annual variation of glucocorticoids, in fact MGL is up-regulated in presence of dexamethasone in vitro. The seasonal variation of this receptor could be an important point in the field of tumor vaccination strategies.
Mechanisms of Enhanced Antigen Delivery to Murine Dendritic Cells by the Cationic Liposomes  [PDF]
Saeko Takahashi, Rui Tada, Yoichi Negishi, Yukihiko Aramaki
Open Journal of Immunology (OJI) , 2017, DOI: 10.4236/oji.2017.74007
Abstract:
There is an increased demand for vaccines to prevent and/or treat illness and mortality caused by the infectious diseases. We have recently established that liposomes composed of cationic lipids act as adjuvant for nasal vaccine formulation. However, the molecular mechanism(s) behind the adjuvant effect remain unrevealed. To this end, we have studied the enhancement of antigen uptake by murine dendritic cell line, DC2.4 cells, by the cationic liposomes and the specific pathways involved in the process. We have observed that the uptake of ovalbumin (OVA) into DC2.4 cells is greatly increased when co-cultured with the cationic liposomes composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl] (DC-chol). However, this enhancement was blocked by pretreatment of DC2.4 cells with chlorpromazine and methyl-β-cyclodextrin, indicating the involvement of clathrin- and caveolin-independent lipid raft-dependent endocytic pathways in the process. Our results implied, at least in part, that enhanced uptake of antigens induced by the cationic liposomes could be a possible mechanism for the induction of immune responses. Although further studies are needed to understand the precise mechanisms behind the adjuvant effects of DOTAP/DC-chol liposome, this approach is quite useful for the development of vaccine system to combat various diseases
A??o da pentoxifilina nos dendrócitos dérmicos FXIIIa de placas de psoríase
Carneiro, Sueli Coelho da Silva;Medeiros, Raphael;Magalh?es, Geraldo Magela;Alves, Cleiton;Cuzzi, Tullia;Sotto, Mirian Nacagami;
Anais Brasileiros de Dermatologia , 2005, DOI: 10.1590/S0365-05962005001000009
Abstract: background: there is no consensus about dermal dendrocytes (dd) function on physiopathological events on psoriasis. pentoxifylline (ptx) is a methylxanthine that inhibits many inflammatory mechanisms. objective: the aim was to evaluate ptx effect on dd proliferation of psoriasis through immunohistochemical techniques. material and methods: thirty psoriatic skin specimens before and 8 weeks after 1200mg/day ptx were incubated with primary rabbit antibody anti-factor xiiia and binding antibody conjugated with alkaline phosphatasis. results: factor xiiia+ dd were prominent with large cytoplasm and markedly dendritic morphology. they were present in a diffuse manner in the papillary dermis and around vessels. after ptx they became oval with scarce cytoplasm, showed no dendritic extensions, and were only present in some papillary bodies. conclusion: ptx pharmacological action promotes vessel flow enhancement, endothelial cell adhesivity decrease, and mast cells and dd factor xiiia+ increase. ptx has an inhibitory action on tnf alpha, which could imply in a decrease of dd receptor expression, as ccr7, and maintenance of the tissular stimulus to signalization and migration of precursors, since the etiopathogenic processes would not be affected by the drug.
Células dendríticas en la sepsis: una aproximación a la inmunosupresión postinfecciosa
Sirgo,G.; Claramonte,R.; Chánovas,M.; Esteban,F.; Forcadell,I.; Luna,J.; Masdeu,G.; Vázquez,J. Ramón; Artigas,A.;
Medicina Intensiva , 2010,
Abstract: dendritic cells (dcs) play a decisive role in the immune system, especially in the initial events that determine coordination between the innate and adaptive response. moreover, they are antigen-presenting cells which, through contact with t cells, determine the type of immune responses towards inflammatory or anti-inflammatory. currently, the hypothesis that attributes importance to the development of a post-infectious immunosuppression in the prognosis of the septic patient is growing stronger. it has been possible to verify the role played by these cells in this type of immunosuppression by the significant decrease in the number of dcs and by the dysfunctions in the functional capacity that include, on the one hand, the abnormal cytokine production and, on the other hand, the alterations in communication between the dcs and t cells that constitute an essential immunological fact. further research into the knowledge regarding the dcs, in the context of severe infection, may help to consolidate some encouraging data that indicate these cells as: 1) an effective tool for monitoring the acute infection, 2) a discriminatory variable that may help determine the risk of nosocomial infection and 3) in a longer term, a treatment target that would restore the immunological abnormalities that occur in sepsis.
Distribution of subpopulations of dendritic cells in peripheral blood of patients treated with exogenous thyrotropin
Stasio?ek Mariusz,Adamczewski Zbigniew,Pu?a Bartosz,Krawczyk-Rusiecka Kinga
Thyroid Research , 2012, DOI: 10.1186/1756-6614-5-18
Abstract: Background Dendritic cells (DCs) play a major role as regulators of inflammatory events associated with thyroid pathology. The immunoregulatory function of DCs depends strongly on their subtype, as well as maturation and activation status. Numerous hormonal factors modulate the immune properties of DCs, however, little is known about effects exerted by the hypothalamus-pituitary-thyroid-axis. Recently, we have shown a direct regulatory influence of thyroid hormones (TH) on human DCs function. The aim of the present study was to analyze the effect of systemically administered thyrotropin (TSH) on human blood DCs ex vivo. Methods Blood samples for the cytometric analysis of peripheral blood plasmacytoid and myeloid DCs subtypes were collected from patients subjected to total thyroidectomy because of differentiated thyroid carcinoma at 2 time points: (i) directly before the commencement of TSH administration and (ii) 5 days after first TSH injection. The whole blood quantitative and phenotypic analysis of plasmacytoid and myeloid DCs subtypes was performed by flow cytometry. Results Administration of TSH did not influence the percentage of plasmacytoid DCs in peripheral blood of study participants. Also the percentage of the two main myeloid DCs subpopulations – CD1c/BDCA1+ DCs and CD141/BDCA3+ DCs did not change significantly. TSH administration had no effect on the surface expression of CD86 – one of the major costimulatory molecules – neither in the whole peripheral blood mononuclear cell (PBMC) fraction nor in particular DCs subtypes. Conclusions In the present study, we demonstrated no influence of systemic TSH administration on human peripheral blood DCs subtypes. These results are in accordance with our previous work suggesting the direct effect of TH on human DCs ex vivo.
Poly-I:C Decreases Dendritic Cell Viability Independent of PKR Activation  [PDF]
Hjalte List Larsen, Anders Elm Pedersen
Journal of Immune Based Therapies, Vaccines and Antimicrobials (JIBTVA) , 2012, DOI: 10.4236/jibtva.2012.11001
Abstract: Vaccination with tumor-antigen pulsed, monocyte-derived dendritic cells (DCs) has emerged as a promising strategy in cancer immunotherapy. The standard DC maturation cocktail consists of a combination of tumor necrosis factor-α (TNF-α)/interleukin (IL)-1β/IL-6 and prostaglandin E2 (PGE2) for generation of standard DCs (sDCs). In order to improve IL-12p70 production and cytotoxic T-lymphocyte (CTL) induction, a novel cocktail composed of TNF-α/IL-1β/ interferon (IFN)-α/IFN-γ and polyinosinic:polycytidylic acid (Poly-I:C) has been introduced to generate so-called α-Type-1 polarized DCs (αDC1s). We and others have previously performed a comprehensive comparison of sDCs and αDC1s. Here we demonstrate that the viability of αDC1s is lowered compared to sDCs and that DC apoptosis is mediated by Poly-I:C. We speculated that activation of protein kinase R (PKR) could mediate the observed apoptosis, but despite significantly higher PKR expression in αDC1s compared to sDCs and induction of active threonine (Thr)446 autophosphorylation of PKR in αDC1s, Poly-I:C did not influence total PKR expression or autophosporylation, indicating PKR-independent Poly-I:C-induced DC apoptosis.
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