BACKGROUND: Previous observations have established that IFN-gamma production is depressed in CD4+ T cells from atopic asthmatics compared with non-asthmatics. OBJECTIVE: The aim of this study was to determine if decreased IFN-gamma production could be due to a dissociation between levels of apoptosis within the T cell subsets of the asthmatic bronchial wall. METHODS: Twenty asthmatics (10 atopic and 10 non-atopic) and eight non-atopic non-asthmatics underwent bronchoscopy. Cryostat sections of these biopsies were investigated using immunohistological techniques to determine the relative number of CD4/FAS+ and CD4/Bcl-2+ cells. Detection of IFN-gamma+ and IL-4+ was combined with TUNEL staining to determine the proportions of the Th1 and Th2 cells undergoing apoptosis. RESULTS: Experiments revealed raised proportions of activated CD4+ T cells as assessed by expression of HLA-DR and CD25+ expression in the asthmatic samples. Expression of Bcl-2 by the CD4+ cell population was significantly reduced in the asthmatic compared with the control group (P = 0.002). There was no significant difference in the expression of CD4+ Fas-ligand or the number of CD4+ undergoing apoptosis in the asthmatic and non-asthmatic groups. However, the IFN-gamma+ (P = 0.04) but not IL-4+ T cells in the asthmatic biopsies had significantly higher proportions of apoptotic cells compared with the control group. CONCLUSION: The evidence supports the hypothesis that Th1/Th2 imbalance in asthmatic inflammation may be a result of premature apoptosis within the Th1 subset.
BACKGROUND: Previous observations have established that IFN-gamma production is depressed in CD4+ T cells from atopic asthmatics compared with non-asthmatics. OBJECTIVE: The aim of this study was to determine if decreased IFN-gamma production could be due to a dissociation between levels of apoptosis within the T cell subsets of the asthmatic bronchial wall. METHODS: Twenty asthmatics (10 atopic and 10 non-atopic) and eight non-atopic non-asthmatics underwent bronchoscopy. Cryostat sections of these biopsies were investigated using immunohistological techniques to determine the relative number of CD4/FAS+ and CD4/Bcl-2+ cells. Detection of IFN-gamma+ and IL-4+ was combined with TUNEL staining to determine the proportions of the Th1 and Th2 cells undergoing apoptosis. RESULTS: Experiments revealed raised proportions of activated CD4+ T cells as assessed by expression of HLA-DR and CD25+ expression in the asthmatic samples. Expression of Bcl-2 by the CD4+ cell population was significantly reduced in the asthmatic compared with the control group (P = 0.002). There was no significant difference in the expression of CD4+ Fas-ligand or the number of CD4+ undergoing apoptosis in the asthmatic and non-asthmatic groups. However, the IFN-gamma+ (P = 0.04) but not IL-4+ T cells in the asthmatic biopsies had significantly higher proportions of apoptotic cells compared with the control group. CONCLUSION: The evidence supports the hypothesis that Th1/Th2 imbalance in asthmatic inflammation may be a result of premature apoptosis within the Th1 subset.
Authors: Gabriel Moran; Virginia A Buechner-Maxwell; Hugo Folch; Claudio Henriquez; Juan S Galecio; Barbara Perez; Cristian Carrasco; Miguel Barria Journal: Vet Res Commun Date: 2011-05-19 Impact factor: 2.459
Authors: S Hirosako; E Goto; K Fujii; K Tsumori; N Hirata; S Tsumura; H Kamohara; H Kohrogi Journal: Clin Exp Immunol Date: 2008-11-26 Impact factor: 4.330
Authors: J Sarmiento; B Perez; N Morales; C Henriquez; L Vidal; H Folch; J S Galecio; G Morán Journal: Vet Res Commun Date: 2013-07-12 Impact factor: 2.459