Priming effect of RANTES on eosinophil oxidative metabolism

Background RANTES has been shown to possess chemotactic activity for eosino phils, which have also been considered to play a role in allergic inflammat ion through reactive oxygen species. Thus, in this study, we examined the e ffect of RANTES on radical oxygen products from eosinophils. Methods Purified eosinophils by CD16-negative selection or an eosinophilic cell Line (EoL-1) were incubated with or without RANTES (2.5 x 10(-6) M). T o the mixture of eosinophils and luminol, calcium ionophore (A23187) or ops onized zymosan (OZ) was added, and radical oxygen products were determined by luminol-dependent chemiluminescence for 600 s. Results Eosinophil-mediated radical oxygen products of untreated eosinophil s produced with A23187 gave a peak Value of 14.09 +/- 2.40 (mean+/-SE, n=12 ) relative light units (RLU) and an integrated value of 3232.20 +/-513.09 R LU. However, with treatment with RANTES, a peak value of 18.66 +/- 2.40 RLU and an integrated value of 5301.05 +/- 561.02 RLU were obtained. Eosinophi l oxidative metabolism-induced A23187 or OZ was apparently augmented by the preincubation with RANTES. In addition, the radical oxygen products of EoL -1 showed similar results. Conclusions Thus, we concluded that RANTES may play an important role in th e pathogenesis of allergic inflammation through its involvement in eosinoph il activation, as evidenced by oxygen products, as well as in selective eos inophil infiltration as selective eosinophil chemoattractant.