Immunohistological detection of interleukin I-like molecules and tumour necrosis factor in human epidermis before and after UVB-irradiation in vivo.

Skin biopsies from five healthy subjects, taken before and after UVB irradiation, were examined using immunohistological techniques for the cytokines interleukin-I (IL-I) and tumour necrosis factor (TNF). Using polyclonal specific antibodies against IL-I and TNF, the two cytokines appeared identically located on the epidermal cell membranes of the stratum granulosum and stratum spinosum in unexposed skin. After UVB-exposure, the staining intensity for both IL-I/epidermal cell derived thymocyte-activating factor (ETAF) and TNF was markedly increased, and the epidermal staining included the basal cell layer. Immunohistological investigation of tissue-bound epidermal cytokines may be valuable in the study of skin diseases.