CCL27 and CCL17 are chemokines believed to be involved in the process of establishing the inflammatory infiltrate, characteristic for the various inflammatory skin diseases. The skin-specific CCL27 binds the chemokine receptor-10 (CCR10), and CCL17 is a chemokine receptor-4 (CCR4) ligand. The purpose of our study was to characterize the expression of CCL27 and CCL17 in the inflammatory skin diseases: psoriasis, atopic dermatitis (AD) and acute allergic contact dermatitis (ACD) induced in nickel-sensitive individuals. Surprisingly, our studies revealed a markedly decreased CCL27 mRNA and protein expression in psoriatic lesions compared with non-lesional psoriatic skin. A minor CCL17 mRNA increase was measured in lesional psoriatic skin. No alterations were found in AD. In ACD, we found a pronounced (90-fold) raise in CCL17 mRNA and a 50-fold increase in CCL17 protein compared with normal skin. A kinetic ACD study of CCL17 expression showed the highest mean value 24 h after hapten application. Furthermore, we found the mRNA levels of CCR10 and CCR4 paralleling the results of their corresponding ligands. Overall, our principal findings were a distinct decrease in CCL27 in lesional psoriatic skin and a marked upregulation of CCL17 in ACD. These findings underscore the differential cutaneous T-cell recruitment in different inflammatory diseases.
© 2011 John Wiley & Sons A/S.