Search results for " t-lymphocytes"
showing 10 items of 495 documents
Inhibitors of β-catenin affect the immuno-phenotype and functions of dendritic cells in an inhibitor-specific manner
2015
Many tumors are characterized by mutation-induced constitutive activation of β-catenin which promotes tumor growth and survival. Consequently, the development of specific β-catenin inhibitors for tumor therapy has come into the focus of drug development. β-Catenin was also shown to contribute to the tolerance-promoting function of unstimulated dendritic cells (DCs). In response to activation, DCs acquire potent T cell stimulatory capacity and induce profound tumor antigen-specific immune responses. Here we asked for effects of pre-clinically established β-catenin inhibitors (CCT-031374, iCRT-5, PNU-75654) on mouse bone marrow-derived (BM)DCs. All three inhibitors moderately increased surfac…
Ci8 short, a novel LPS-induced peptide from the ascidian Ciona intestinalis,modulates responses of the human immune system
2017
The selective modulation of immunity is an emerging concept driven by the vast advances in our understanding of this crucial host defense system. Invertebrates have raised researchers’ interest as potential sources of new bioactive molecules owing to their antibacterial, anticancer and immunomodulatory activities. A LipoPolySaccharide (LPS) challenge in the ascidian Ciona intestinalis generates the transcript, Ci8 short, with cisregulatory elements in the 3′ UTR region that are essential for shaping innate immune responses. The derived amino acidic sequence in silico analysis showed specific binding to human Major Histocompatibility Complex (MHC) Class I and Class II alleles. The role of Ci…
Glycoprotein 96-activated dendritic cells induce a CD8-biased T cell response.
2005
Heat shock proteins (Hsps) are able to induce protective immune responses against pathogens and tumors after injection into immunocompetent hosts. The activation of components of the adaptive immune system, including cytotoxic T lymphocytes specific for pathogen- or tumor-derived peptides, is crucial for the establishment of immuno- protection. Hsps acquire these peptides during intracellular protein degradation and when released during necrotic cell death, facilitate their uptake and Minor Histocompatibility Complex (MHC)-restricted representation by professional antigen-presenting cells (APCs). In addition, the interaction of Hsps with APCs, including the Endoplasmatic Reticulum (ER)-resi…
Blue light irradiation suppresses dendritic cells activationin vitro
2013
Blue light is a UV-free irradiation suitable for treating chronic skin inflammation, for example, atopic dermatitis, psoriasis, and hand- and foot eczema. However, a better understanding of the mode of action is still missing. For this reason, we investigated whether dendritic cells (DC) are directly affected by blue light irradiation in vitro. Here, we report that irradiation neither induced apoptosis nor maturation of monocyte-derived and myeloid DC. However, subsequent DC maturation upon LPS/IFNγ stimulation was impaired in a dose-dependent manner as assessed by maturation markers and cytokine release. Moreover, the potential of this DC to induce cytokine secretion from allogeneic CD4 T …
A trifunctional dextran-based nanovaccine targets and activates murine dendritic cells, and induces potent cellular and humoral immune responses in v…
2013
Dendritic cells (DCs) constitute an attractive target for specific delivery of nanovaccines for immunotherapeutic applications. Here we tested nano-sized dextran (DEX) particles to serve as a DC-addressing nanocarrier platform. Non-functionalized DEX particles had no immunomodulatory effect on bone marrow (BM)-derived murine DCs in vitro. However, when adsorbed with ovalbumine (OVA), DEX particles were efficiently engulfed by BM-DCs in a mannose receptor-dependent manner. A DEX-based nanovaccine containing OVA and lipopolysaccharide (LPS) as a DC stimulus induced strong OVA peptide-specific CD4(+) and CD8(+) T cell proliferation both in vitro and upon systemic application in mice, as well a…
Murine liver antigen presenting cells control suppressor activity of CD4+CD25+ regulatory T cells.
2005
CD4(+)CD25(+) regulatory T cells (Treg) are important mediators of peripheral immune tolerance; however, whether Treg participate also in hepatic immune tolerance is not clear. Therefore, we tested the potential of Treg to suppress stimulation of CD4(+) T cells by liver sinusoidal endothelial cells (LSEC), Kupffer cells (KC), or hepatocytes. In the absence of Treg, all 3 types of liver cells could stimulate CD4(+) T cell proliferation; in the presence of Treg, however, CD4(+) T cell proliferation was suppressed. Interaction with KC even stimulated the expansion of the Treg population; LSEC or hepatocytes, in contrast, could not induce proliferation of Treg. Because liver inflammation can be…
Anti-tumor activity of CpG-ODN aerosol in mouse lung metastases
2013
Studies in preclinical models have demonstrated the superior anti-tumor effect of CpG oligodeoxynucleotides (CpG-ODN) when administered at the tumor site rather than systemically. We evaluated the effect of aerosolized CpG-ODN on lung metastases in mice injected with immunogenic N202.1A mammary carcinoma cells or weakly immunogenic B16 melanoma cells. Upon reaching the bronchoalveolar space, aerosolized CpG-ODN activated a local immune response, as indicated by production of IL-12p40, IFN-γ and IL-1β and by recruitment and maturation of DC cells in bronchoalveolar lavage fluid of mice. Treatment with aerosolized CpG-ODN induced an expansion of CD4+ cells in lung and was more efficacious tha…
A method to enable the investigation of murine bronchial immune cells, their cytokines and mediators.
2007
Innovative therapies for severe lung diseases (such as allergic and chronic asthma, chronic obstructive pulmonary disease or any type of lung cancer) require a detailed understanding of the cellular and immune processes in the lung. This protocol details a method to obtain the immune cells of the bronchi as well as the cytokines and mediators produced by these cells for further investigation. The broncho-alveolar lavage fluid (BALF) is taken by injecting physiological solution through the tracheal tube into the murine airways and carefully regained by winding up the connected syringe. After centrifugation, the resulting BALF supernatant can be stored for detection of cytokines or other medi…
Defective T helper response of hepatocyte-stimulated CD4 T cells impairs antiviral CD8 response and viral clearance.
2007
Background & Aims: In hepatitis, hepatocytes gain the ability to express major histocompatibility complex (MHC) class II molecules and to present antigen to CD4 T cells. Here, we investigated whether MHC class II-expressing hepatocytes influence in vitro the differentiation of CD4 T cells and in vivo the T-cell response to and control of viral infection. Methods: Class II transactivator-transgenic hepatocytes that constitutively express MHC class II molecules were used to stimulate CD4 T cells in vitro, and the effector response type of the stimulated CD4 T cells was determined. The in vivo relevance of the obtained findings was confirmed by infecting nontransgenic or class II transactivato…
Epicutaneous and Oral Low-Zone Tolerance Protects from Colitis in Mice
2016
Tolerance to environmental antigens that encounter the organism at interfaces like skin or gut prevents deleterious systemic immune responses. The aim of this study was to analyze whether and how low doses of haptens, by entry through the skin or gastrointestinal tract, affect the outcome of the predominantly Th1/Th17-mediated 2,4,6-trinitro-benzenesulfonic acid-induced colitis, which mimics an autoimmune bowl disease in man. Epicutaneous and oral applications of low doses of the allergen resulted in the induction of low-zone tolerance (LZT) and protected from colitis development, demonstrated by a significantly reduced inflammatory response of the gut in vivo. In line with this observation…