Search results for "Dendritic Cell"
showing 10 items of 447 documents
Allogeneic effector/memory Th-1 cells impair FoxP3+ regulatory T lymphocytes and synergize with chaperone-rich cell lysate vaccine to treat leukemia
2011
AbstractTherapeutic strategies combining the induction of effective antitumor immunity with the inhibition of the mechanisms of tumor-induced immunosuppression represent a key objective in cancer immunotherapy. Herein we demonstrate that effector/memory CD4+ T helper-1 (Th-1) lymphocytes, in addition to polarizing type-1 antitumor immune responses, impair tumor-induced CD4+CD25+FoxP3+ regulatory T lymphocyte (Treg) immunosuppressive function in vitro and in vivo. Th-1 cells also inhibit the generation of FoxP3+ Tregs from naive CD4+CD25−FoxP3− T cells by an interferon-γ–dependent mechanism. In addition, in an aggressive mouse leukemia model (12B1), Th-1 lymphocytes act synergistically with …
Cladribine exerts an immunomodulatory effect on human and murine dendritic cells
2014
Cladribine is a purine nucleoside analog developed to treat lymphoid malignancies. Reported therapeutic benefits for the autoimmune disease multiple sclerosis indicate additional immunomodulatory effects beyond the well-characterized cytotoxic activity causing lymphopenia. Here, we demonstrate that cladribine reduces the secretion of inflammatory cytokines and chemokines by murine and human dendritic cells, the most potent antigen-presenting cells. This compound also modulates the expression of the activation markers CD86 and MHC II. Furthermore, cladribine affects the T cell priming capacity of dendritic cells, resulting in reduced induction of interferon-γ- and tumor necrosis factor-α-pro…
Interleukin-10-treated dendritic cells do not inhibit Th2 immune responses in ovalbumin/alum-sensitized mice.
2005
<i>Background:</i> It is well known that the immunoregulatory cytokine interleukin (IL)-10 inhibits the accessory function of human dendritic cells (DC) in vitro. Recently, we have shown that these IL-10 DC inhibit the production of T helper cell 1 (Th1) and T helper cell 2 (Th2) cytokines by T cells from atopic individuals in vitro. The current study was set out to analyze whether IL-10 DC also exert inhibitory effects in vivo in a murine model of allergy to ovalbumin adsorbed to the adjuvant aluminium hydroxide (OVA/alum). <i>Methods:</i> OVA-pulsed or unpulsed bone marrow-derived DC, treated with IL-10 or left untreated during generation, were injected intravenous…
Microparticles: Modulators and biomarkers of liver disease
2012
Division of Molecular and Translational Medicine,Dept. of Medicine I, Johannes Gutenberg University, Mainz, GermanyEmerging role of microparticlesMicroparticles (MP) have gained increasing attention as biomark-ers for various diseases. First described as platelet dust, MP wereregarded as unspecific debris [1]. However, it has become appar-ent that cell derived MP or ectosomes represent a novel route ofhorizontal communication between cells. MP are between 100–1000 nm in size and generated through cell membrane shedding(ectocytosis), a process that can be triggered by the activation ofthe complement C5b-9 complex, as shown for platelet derivedMP, or by inhibition of flippase activitythroughCa
Surface Modification of Polysaccharide-Based Nanoparticles with PEG and Dextran and the Effects on Immune Cell Binding and Stimulatory Characteristic…
2017
Surface modifications of nanoparticles can alter their physical and biological properties significantly. They effect particle aggregation, circulation times, and cellular uptake. This is particularly critical for the interaction with primary immune cells due to their important role in particle processing. We can show that the introduction of a hydrophilic PEG layer on the surface of the polysaccharide-based nanoparticles prevents unwanted aggregation under physiological conditions and decreases unspecific cell uptake in different primary immune cell types. The opposite effect can be observed with a parallel-performed introduction of a layer of low molecular weight dextran (3.5 and 5 kDa) on…
Multivalency Beats Complexity: A Study on the Cell Uptake of Carbohydrate Functionalized Nanocarriers to Dendritic Cells.
2020
Herein, we report the synthesis of carbohydrate and glycodendron structures for dendritic cell targeting, which were subsequently bound to hydroxyethyl starch (HES) nanocapsules prepared by the inverse miniemulsion technique. The uptake of the carbohydrate-functionalized HES nanocapsules into immature human dendritic cells (hDCs) revealed a strong dependence on the used carbohydrate. A multivalent mannose-terminated dendron was found to be far superior in uptake compared to the structurally more complex oligosaccharides used.
Tumor-derived lactic acid modulates dendritic cell activation and antigen expression.
2005
The tumor milieu can influence dendritic cell (DC) differentiation. We analyzed DC differentiation in a 3-dimensional tumor model and propose a new mechanism of DC modulation by the tumor environment. Monocytes were cultured in the presence of IL-4 and GM-CSF within multicellular tumor spheroids (MCTSs) generated from different tumor cell lines. Monocytes invaded the MCTSs and differentiated into tumor-associated dendritic cells (TADCs). The antigen expression was altered on TADCs independent of the culture conditions (immature/mature DCs, Langerhans cells) and IL-12 secretion was reduced. Supernatants of MCTSs could partially transfer the suppressive effect. Conditioned media from urotheli…
Monocyte-derived dendritic cells of patients with coronary artery disease show an increased expression of costimulatory molecules CD40, CD80 and CD86…
2007
Background Atherosclerosis is a disease triggered by diverse exogenous stimuli and sustained by chronic inflammatory processes. Dendritic cells (DCs) are key regulatory antigen-presenting cells and play a crucial role in regulating the adaptive and innate immune system in any chronic inflammatory process. DCs are present in atherosclerotic lesions in the areas of the highest T-cell density. So far, their role in atherosclerosis has not been fully elucidated. We investigated the phenotypic properties of DCs in patients with coronary artery disease (CAD) in comparison to healthy individuals. Methods Peripheral blood monocytes were isolated from 50 patients with CAD and 19 healthy individuals …
Particle-Mediated Gene Transfer into Dendritic Cells: A Novel Strategy for the Induction of Immune Responses against Tumor Antigens
2003
The expression of a foreign protein in the skin following direct in vivo gene transfer results in the induction of potent cellular and humoral immune responses. This strategy, now known as genetic or DNA immunization, was first described by Johnston et al. in 1992. They reported that bombardment of murine skin with an expression plasmid encoding human growth hormone coated onto microscopic gold particles using a gene gun resulted not only in the systemic delivery of the molecule, but also in the induction of antigenspecific antibody responses (1). It is now well established that DNA immunization by particle-mediated gene transfer promotes broad-based and long-lasting antigen-specific immune…
Requirements for Th1-dependent immunity against infection with Leishmania major
2004
Protective immunity against cutaneous leishmaniasis is dependent on the induction of Th1/Tc1 immune responses resulting in efficient parasite elimination. In this review, the mechanisms leading to protection are discussed with special focus on the role of Leishmania major-infected dendritic cells (DC) in induction of Th1-dependent immunity. Murine strain-dependent differences between DC derived from Leishmania-susceptible as compared to resistant mice are highlighted.