Cytokine transcript profiling in CD34+-progenitor derived dendritic cells exposed to contact allergens and irritants

We here investigated wether genes encoding the interleukins IL-1beta, IL-6 and IL-8, and the chemokines CCL2, CCL3, CCL3L1 and CCL4 are useful markers for sensitization testing in CD34+-progenitor derived dendritic cells (CD34-DC). CD34-DC from at least three donors were exposed during 0.5 up to 24h to the chemical sensitizers nickel sulphate, oxazolone, 2,4-dinitrochlorobenzene (DNCB) and eugenol, and to the irritants sodium dodecyl sulphate (SDS) and benzalkonium sulphate (BC). mRNA expression was evaluated using real-time RT-PCR. We observed a large inter-individual variation in mRNA expression in CD34-DC exposed to the chemicals. No or limited effects on expression were observed for the irritant BC and the weak sensitizer eugenol. All other chemicals modulated the transcript levels of most cytokines that were investigated. Most of the time, no clear-cut distinctions could be made between the sensitizers and SDS. After 24 h, consistent upregulatory effects of all sensitizing compounds on transcript expression of CCL2, CCL3 and CCL4 were observed, whereas SDS (and BC) had no effect. Our findings suggest that the CCL2, CCL3 and CCL4 genes may be selective end-point markers in the CD34-DC model to discern chemical sensitizers from irritants.