Epidermal cell-derived thymocyte activating factor (ETAF) is a potent T-cell chemoattractant.

The epidermis, in particular epidermal cytokines, have been shown to modulate a number of inflammatory and cellular immune responses. In this study we have demonstrated that the partially purified epidermal cytokine, epidermal thymocyte activating factor (ETAF), a polypeptide released by keratinocytes, is a potent T-cell chemoattractant. Compared to its ability to augment lectin-stimulated thymocyte proliferation, ETAF is much more active as a T-cell chemoattractant. The results of this study give further support to the role of local epidermal factors in immune reactivity. This finding may have particular relevance to pathologic states characterized by T-cell infiltration in the skin, such as cutaneous T-cell lymphoma.