Cytokines and chemokines in the epidermis

Keratinocytes (KC) produce a vast repertoire of cytokines, including interl eukins, growth factors, colony stimulating factors, and chemokines. Under n ormal conditions, most of them are not synthesized or remain in the cytopla sm, but external stimuli, such as trauma, bacterial infections, chemical su bstances, or ultraviolet irradiation induce the production and release of t hese cytokines from KC. KC-derived cytokines regulate the immune and inflam matory responses through their receptors on KC, Langerhans cells, dermal fi broblasts and endothelial cells, and infiltrating T-cells. (C) 2000 Elsevie r Science Ireland Ltd. All rights reserved.