Previous research has suggested that fear of flying, which is defined as a situational, specific phobia, could overlap with depressive and anxiety disorders. Whether the neuronal dysfunctions including altered serotonergic activity in the brain and altered neural oscillations observed for depressive and anxiety disorders also overlap with alterations in fear of flying is unclear. Here, thirty-six participants with self-reported fear of flying (FF) and forty-one unaffected participants (NFF) were recruited.
View Article and Find Full Text PDFArb Paul Ehrlich Inst Bundesamt Sera Impfstoffe Frankf A M
May 2004
The inducible costimulator (ICOS), a newly identified member of the CD28 receptor family that is induced after T-cell activation, and its ligand (ICOSL), being expressed on activated monocytes and dendritic cells play a key role in T-cell-mediated immune responses. As ICOS costimulation also seems to regulate T helper 2 effector cells, the aim of this study was to analyse the function of this molecule in allergic immune responses and their specific therapy, mainly venom immunotherapy (VIT). CD4+ T cells from grass pollen-, or bee or wasp venom-allergic donors were stimulated in the presence of autologous mature dendritic cells, which were pulsed with different allergen doses.
View Article and Find Full Text PDFBackground: 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.
Background: Recently, it has been established that CD4(+)CD25(+) T cells with regulatory capacity are present in human peripheral blood, inhibiting allogeneic proliferation and cytokine production of preactivated CD4(+)CD25(-) respond-er T cells.
Objective: The aim of this study was to analyze in an allergen-specific setting whether such regulatory CD4(+)CD25(+) T cells also exist and function normally in atopic individuals, especially concerning the inhibition of T(H)2 cytokines.
Methods: For this purpose, CD4(+)CD25(-) or CD4(+)CD25(+) T cells from donors allergic to grass or birch pollen (mainly with rhinitis) or from healthy nonatopic donors were stimulated in the presence of autologous, mature, monocyte-derived, allergen-pulsed dendritic cells, and the preactivated CD4(+)CD25(+) T cells were added to CD4(+)CD25(-) T cells during restimulation.
Dendritic cells (DC) are able to induce not only T helper 1 (Th1) but also Th2 immune responses after stimulation with allergens. While DC-derived interleukin (IL)-12 and IL-18 are the key factors for the induction of Th1 cells, early signals being involved in Th2 differentiation are less well characterized so far. To analyse such early signals we used an antigen-specific setting with CD4+ T cells from atopic donors stimulated in the presence of autologous mature DC, which were pulsed with different allergen doses.
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