Immunocytochemical detection of the carbohydrate antigen, Sialyl Lewis(x), in normal human skin and during irritant contact dermatitis.

Sialys Lewis(x) (SLex) is a ligand for the E-selectin and the interaction of E-selectin on the endothelium and SLex on T cells may be important for T-cell migration into the skin. We investigated the expression of SLex on Langerhans cells (LC) in normal skin and on LC repopulating epidermis deprived of LC due to a preceding irritant contact dermatitis. SLex was visualized by fluorescence and light microscopic immunocytochemistry using the monoclonal antibody, CSLEX-1. The results showed that about 40% of LC in normal epidermis express SLex. In the repopulation phase, most of the epidermal cells were CD1a+/SLex. We suggest that SLex is present on epidermal LC that have recently immigrated from the dermis.