Search results for "interleukin"
showing 10 items of 1856 documents
Regulatory activity of human CD4 CD25 T cells depends on allergen concentration, type of allergen and atopy status of the donor.
2005
Regulatory CD4+ CD25+ FoxP3-positive T cells (Treg) are functional in most atopic patients with allergic rhinitis and are able to inhibit T helper type 1 (Th1) and Th2 cytokine production of CD4+ CD25- T cells. This study was designed to analyse the following additional aspects: influence of allergen concentration, influence of the type of allergen, and influence of the atopy status of the donor on the strength of the regulatory activity. CD4+ CD25- T cells from healthy non-atopic controls or from grass-pollen-allergic or wasp-venom-allergic donors were stimulated alone or in the presence of Treg with autologous mature monocyte-derived dendritic cells which were pulsed with different concen…
Inhibition of human allergic T-cell responses by IL-10–treated dendritic cells: Differences from hydrocortisone-treated dendritic cells
2001
Abstract Background: Dendritic cells (DCs) are able to induce human allergic T H 1 responses as well as T H 2 responses. Objective: In this study, we examined the effect of antiinflammatory agents such as IL-10 and hydrocortisone (HC) on the accessory function of DCs and the resulting T-cell response, especially that of T H 2 cells. Methods: Naive and memory CD4 + T cells from atopic donors were stimulated with autologous allergen-pulsed DCs generated from CD14 + monocytes by culture with GM-CSF/IL-4 and fully matured with IL-1β, TNF-α, and PGE 2 in the presence or absence of IL-10 or HC. Results: IL-10–treated DCs and, to a lesser extent, HC-treated DCs showed a decreased expression of MHC…
Modification of the human allergic immune response by allergen-DNA-transfected dendritic cells in vitro.
2004
Abstract Background Atopic-allergic diseases are characterized by T H 2-dominated immune responses, resulting in IgE production. DNA-based immunotherapies have been shown to shift the immune response toward a T H 1-type response in animal models. Objective The aim of the study was to analyze whether dendritic cells (DCs) transfected with allergen-DNA conjugates are able to stimulate human autologous CD4 + T cells, CD8 + T cells, or both from atopic individuals to produce T H 1 cytokines instead of T H 2 cytokines. Methods For this purpose, human mature DCs from atopic donors were transfected with an adenovirus encoding the allergen Phl p 1. Autologous CD4 + and CD8 + T cells were stimulated…
The Regulatory T Cell Family: Distinct Subsets and their Interrelations
2003
The immune system, a highly effective and dynamic cellular network, protects a host from pathogens. Therefore, the immune system must distinguish self from nonself structures, but also between harmful and innocuous foreign Ags to prevent nonessential and self-destructive immune responses. The
Direct Cellular Interaction with Activated CD4+T Cells Overcomes Hyporesponsiveness of B-Cell Chronic Lymphocytic Leukemiain Vitro
1998
The proliferative response of clonal B cells from patients with chronic lymphocytic leukemia (B-CLL) is drastically reduced compared to normal B lymphocytes stimulated via the B cell antigen receptor complex or by CD40 ligation. In the present study we demonstrate that hyporesponsiveness of CLL-B cells can be overcome by stimulatory pathways mediated by activated CD4(+) T cells. In contrast to CD40 ligation, costimulation with activated T cells promotes a proliferative response in CLL-B cells identical to that in normal B cells. Furthermore, coculture with activated T cells improved survival of CLL-B cells in vitro. Differentiation of CLL-B cells into IgM producing cells was promoted, as we…
Cutting Edge: TGF-β Induces a Regulatory Phenotype in CD4+CD25− T Cells through Foxp3 Induction and Down-Regulation of Smad7
2004
Abstract CD4+CD25+ regulatory cells are a subpopulation of T lymphocytes of thymic origin. However, recent data suggest an alternative commitment of regulatory T cells in the periphery, although the precise mechanism is unknown. In the present work, we demonstrate that TGF-β is able to induce Foxp3 expression and subsequently a regulatory phenotype in CD4+CD25− peripheral murine T cells. Similarly, TGF-β induced Foxp3 in human CD4+CD25− T cells. Moreover, we show that the inhibitory Smad7 protein that is normally induced by TGF-β and limits TGF-β signaling, is strongly down-regulated by Foxp3 at the transcriptional level. Foxp3-mediated down-regulation of Smad7 subsequently rendered CD4+CD2…
Hematopoietic Growth Factors Are Differentially Regulated in Monocytes and CD4+T Lymphocytes: Influence of IFN-α and Interleukin-4
1998
We investigated the influence of interferon-alpha (IFN-alpha) on the synthesis of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) by monocytes and activated T helper cells. IFN-alpha inhibited the production of GM-CSF in unstimulated and lipopolysaccharide (LPS)-activated monocytes to the same extent as was observed in the presence of IL-4. In highly purified CD4+ T cells, which were activated by incubation with immobilized anti-CD3 antibody and anti-CD28, IFN-alpha reduced production of GM-CSF to 47%. In contrast, GM-CSF production in activated T cells was unaffected by exogenously added IL-4. The production of IL-3 by T helper cells was significantly inh…
Differential Regulatory Capacity of CD25+ T Regulatory Cells and Preactivated CD25+ T Regulatory Cells on Development, Functional Activation, and Pro…
2004
Abstract CD25+ T regulatory (Treg) cells play a central role regarding the maintenance of peripheral tolerance via suppression of autoaggressive CD4+ T cells, CD8+ T cells, and Th1 cells. In this study we demonstrate that CD25+ Treg cells can also suppress the differentiation of murine conventional CD4+ T cells toward Th2 cells in a contact-dependent manner. However, the cytokine production and proliferation of established Th2 cells could not be inhibited by freshly isolated CD25+ Treg cells, whereas a strong inhibition of differentiated Th2 cells by in vitro preactivated CD25+ Treg cells could be observed. Inhibition of both conventional CD4+ T cells and Th2 cells is accompanied by a stron…
Asthmatic changes in mice lacking T-bet are mediated by IL-13
2005
Mice with a targeted deletion of the T-bet gene exhibit spontaneous airway hyperresponsiveness (AHR), airway inflammation, enhanced recovery of T(h)2 cytokines from bronchoalveolar lavage fluid, sub-epithelial collagen deposition and myofibroblast transformation. Here we analyze the mechanisms responsible for the chronic airway remodeling observed in these mice. CD4+ T cells isolated from the lung of T-bet-deficient mice were spontaneously activated CD44(high)CD69(high) memory T cells, with a typical T(h)2 cytokine profile. Neutralization of IL-13 but not IL-4 resulted in amelioration of AHR in airways of mice lacking T-bet. IL-13 blockade also led to reduced eosinophilia and decreased vime…
The receptor NLRP3 is a transcriptional regulator of TH2 differentiation.
2015
The receptor NLRP3 is involved in the formation of the NLRP3 inflammasome that activates caspase-1 and mediates the release of interleukin 1β (IL-1β) and IL-18. Whether NLRP3 can shape immunological function independently of inflammasomes is unclear. We found that NLRP3 expression in CD4(+) T cells specifically supported a T helper type 2 (TH2) transcriptional program in a cell-intrinsic manner. NLRP3, but not the inflammasome adaptor ASC or caspase-1, positively regulated a TH2 program. In TH2 cells, NLRP3 bound the Il4 promoter and transactivated it in conjunction with the transcription factor IRF4. Nlrp3-deficient TH2 cells supported melanoma tumor growth in an IL-4-dependent manner and …