Cell-type-dependent induction of eotaxin and CCR3 by ionizing radiation

Eotaxin is an eosinophil-specific C-C chemokine that is implicated in the p athogenesis of eosinophilic inflammatory diseases, such as asthma and atopi c dermatitis, by acting specifically on its receptor CCR3. Using RT-PCR ana lysis, we show that the expression of eotaxin is upregulated upon treatment with ionizing radiation (Ht) in human dermal fibroblasts, but not in the b ronchial epithelial cell line A549. In contrast, the gene encoding CCR3 is markedly induced in both cell types. None of the genes coding for other CCR 3 ligands are significantly induced by Ut in these cell types. cDNA array a nalysis of irradiated versus nonirradiated A549 cells and human dermal fibr oblasts confirm and extend these results, and support the observation that regulation of eotaxin/CCR3-induction by Ut occurs in a selective and cell-t ype-dependent manner. They further suggest that the induction of signaling via eotaxin and CCR3 may be an important step leading to eosinophilia in pa tients with radiation exposure. (C) 2000 Academic Press.