BACKGROUND: Excessive production of interleukin (IL)-4, IL-5, IL-10, and IL-13 is thought to be important in the development of allergy and asthma. The objective of this investigation was to study Th1/Th2-like cytokine profiles in vitro in seven patients allergic to birch pollen and six nonallergic controls during the birch-pollen season. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated and cultured with birch-pollen extract (BPE) or tetanus toxoid (TT) for 7 days, harvested, and restimulated with the mitogens phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) for 24 h. Cytokine production was determined by ELISA, and logarithmic cytokine ratios were compared between the two groups and between the antigens. RESULTS: In the allergic group, the cultures prestimulated with BPE had a more Th2-like cytokine response than the TT-prestimulated cultures; i.e., lower IFN-gamma and higher IL-10 production (P<0.05), as well as higher IL-5/IFN-gamma and IL-13/ IFN-gamma ratios (P<0.05). There were also significantly higher IL-4/IFN-gamma (P<0.005) and IL-5/IFN-gamma (P<0.05) ratios in BPE-stimulated cultures in the allergic group than in the control group. The IL-4 and IL-13 production in vitro correlated with the specific serum IgE levels. CONCLUSIONS: BPE stimulation induces a Th2-like cytokine response by PBMC isolated during the pollen season from birch-pollen-allergic patients, indicating a Th2-type immune response to birch pollen in vivo.
BACKGROUND: Excessive production of interleukin (IL)-4, IL-5, IL-10, and IL-13 is thought to be important in the development of allergy and asthma. The objective of this investigation was to study Th1/Th2-like cytokine profiles in vitro in seven patients allergic to birch pollen and six nonallergic controls during the birch-pollen season. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated and cultured with birch-pollen extract (BPE) or tetanus toxoid (TT) for 7 days, harvested, and restimulated with the mitogens phytohemagglutinin (PHA) and phorbol 12-myristate 13-acetate (PMA) for 24 h. Cytokine production was determined by ELISA, and logarithmic cytokine ratios were compared between the two groups and between the antigens. RESULTS: In the allergic group, the cultures prestimulated with BPE had a more Th2-like cytokine response than the TT-prestimulated cultures; i.e., lower IFN-gamma and higher IL-10 production (P<0.05), as well as higher IL-5/IFN-gamma and IL-13/ IFN-gamma ratios (P<0.05). There were also significantly higher IL-4/IFN-gamma (P<0.005) and IL-5/IFN-gamma (P<0.05) ratios in BPE-stimulated cultures in the allergic group than in the control group. The IL-4 and IL-13 production in vitro correlated with the specific serum IgE levels. CONCLUSIONS: BPE stimulation induces a Th2-like cytokine response by PBMC isolated during the pollen season from birch-pollen-allergic patients, indicating a Th2-type immune response to birch pollen in vivo.
Authors: K A Whalen; H Legault; C Hang; A Hill; M Kasaian; D Donaldson; G W Bensch; G Bensch; J Baker; P S Reddy; N Wood; M K Ramarao; D K Ellis; C Csimma; C McKee; J D Clark; J Ryan; A J Dorner; M O'Toole Journal: Clin Exp Allergy Date: 2008-07-28 Impact factor: 5.018