Macrophage-derived chemokine (MDC)/CCL22 produced by monocyte derived dendritic cells reflects the disease activity in patients with atopic dermatitis

Abstract

Atopic dermatitis (AD) is a recurrent inflammatory skin disease characterized by high serum levels of IgE and Th2-type cytokines such as IL-4, IL-5 or IL-13. Chemokines attract leukocytes in inflamed tissues. We have previously found that thymus and activation regulated chemokine (TARC)/CCL17 and macrophage-derived chemokine (MDC)/CCL22 are highly secreted in the plasma levels of AD patients. Dendritic cells (DCs) are antigen-presenting cells that are divided into two subgroups including monocyte derived DCs (MoDCs) and plasmacytoid DCs (pDCs). The aim of the study was to elucidate CCL17 and CCL22 production by MoDCs in AD patients, psoriasis vulgaris (PsV) patients and healthy controls (HC). MoDCs were obtained from AD patients, PsV patients or HC and were cultured. In addition, the chemokine levels were measured in the supernatants. We found that the CCL22 levels produced by MoDCs in AD patients to be significantly higher than those of PsV patients and HC. There was a significant correlation between the CCL22 levels produced by MoDCs and the SCORAD index. No significant difference in the CCL17 levels produced by MoDCs was detected among AD patients, PsV patients or HC. Immunosuppressive drugs such as dexamethasone (Dex), tacrolimus and cyclosporine (Cys) inhibited the CCL22 production by MoDCs in the AD patients. These data suggest that the CCL22 level produced by MoDCs thus reflects the disease activity of AD and it may also play an important role regarding the production of CCL22 in the pathogenesis of AD.