Enhanced expression of eotaxin and CCR3 in atopic dermatitis.

Chemokines are thought to play an important part in the development of inflammation in atopic dermatitis. Eotaxin, a CC chemokine, is a potent chemoattractant and activator of human eosinophils, basophils and Th2 lymphocytes which acts via the chemokine receptor CCR3. We studied the expression of eotaxin and CCR3, as well as MCP-3, MIP-1alpha and interleukin-8, in atopic dermatitis and normal skin by immunohistochemistry and nested reverse transcriptase-polymerase chain reaction. Skin biopsy specimens were obtained from nonlesional and lesional skin of patients with atopic dermatitis and of nonatopic controls. Immunoreactivity and transcripts of eotaxin and CCR3 were significantly increased in lesional skin from atopic dermatitis, but not in nonatopic controls. In nonlesional atopic dermatitis samples CCR3 expression was also significantly increased at the mRNA and protein level, whereas eotaxin was increased at the mRNA level only. No significant difference in the expression of MCP-3, MIP-1alpha, and interleukin-8 was observed between skin samples from atopic dermatitis and nonatopic controls. The enhanced local production of eotaxin may lead to the recruitment of eosinophils and T lymphocytes, which both express CCR3 and contribute to the initiation and maintenance of inflammation.