Inhibitory Effect of Budesonide Alone and in Combination with Formoterol on IL-5 and RANTES Production from Mononuclear Cells

Abstract

Background:The use of a budesonide (BUD)/formoterol (FOR) combination (Symbicort®) for both maintenance and reliever therapy reduces the exacerbation of asthma better than the traditional fixed-dose regimens. In the early stage of exacerbation, the combination therapy could intervene with the development of subsequent airway inflammation. The objective of the study was to evaluate whether in the early stage of cell activation the use of BUD/FOR combination would modify the adhesion of eosinophils or production of cytokines from mononuclear cells. Methods:Human peripheral blood eosinophils, pretreated with BUD (0.1 µM), FOR (0.1 µM) or BUD/FOR combination for 30 min at 37°C, were stimulated with IL-5, leukotriene D4 or phorbol myristate acetate, and eosinophil adhesion was evaluated using an eosinophil peroxidase assay. BUD (0.1 µM), FOR (0.1 µM) or BUD/FOR combination was added to the peripheral blood mononuclear cells stimulated with ionomycin plus phorbol myristate acetate. Concentrations of IL-5 and RANTES in the cell supernatant were measured using ELISA. Results:BUD, FOR or BUD/FOR combination did not modify the eosinophil adhesion induced by any stimulators. In contrast, BUD or BUD/FOR combination significantly reduced the productions of IL-5 and RANTES in peripheral blood mononuclear cells (BUD: p < 0.0001, p = 0.027 vs. control; BUD/FOR: p < 0.0001, p = 0.031 vs. control) when the drugs were added 15 min, but not 4 h, following cell stimulation. Conclusion: In the early stage of exacerbation of asthma, inhaled BUD may suppress the progression of the allergic inflammatory cascade by inhibiting the mononuclear cells. These results also underline the importance of using BUD in rescue inhaler.

Effect of beta2-adrenergic agonists on eosinophil adhesion, superoxide anion generation, and degranulation

“…Eosinophils were isolated by negative selection using immunomagnetic beads, as described. 10,11,20,39,40 Over 98% of the cells were eosinophils, as determined by morphologic criteria using May-Grünwald-Giemsa staining. Eosinophil viability was >99%, as determined by Trypan blue dye exclusion.…”

“…10,11,20,39,40 Eosinophils were pre-incubated with formoterol (10 nM/100 nM/1000 nM) or salbutamol (10 nM/100 nM/ 1000 nM) at 37 C for 15 min. The eosinophils (100 ml of 1 Â 10 5 cells/ml in HBSS/gel) were then incubated with or without IL-5 (100 pM), LTD 4 (100 pM), or IP-10 (100 nM) in rh-ICAM-1-coated plates at 37 C for 20 min.…”