Chemokine networks in inflammatory skin diseases.

The superfamily of chemokines comprises numerous small, cytokine-like chemotactic proteins, which have a fundamental role in the regulation of leukocyte trafficking. The chemokine-chemokine receptor system is highly redundant and promiscuous, and forms a complex network relevantly involved in the expression of chronic inflammatory skin diseases, including allergic contact dermatitis, atopic dermatitis and psoriasis. The pattern of chemokine expression shows overlapping features but also important differences in these diseases due to distinct sources and types of pro-inflammatory signals involved in chemokine induction, and the inherent capacity of resident skin cells to produce chemokines. Chemokine receptors (G-protein coupled receptors) rather than chemokines appear the appropriate therapeutic targets as they are more chemically tractable and play less redundant functions.