Skin explant cultures: expression of cytoplasmic differentiation antigens in outgrowth cells.

In vivo, keratinocyte cytoplasmic antigens linked to keratinization have been traced with 2 distinct types of antibodies found in human sera. One type of antibody is specific for the basal cell compartment of keratinocytes while the other one is specific for upper keratinocytes. Using these markers, we followed a well-defined, in vitro human keratinocyte culture system that produces a keratinizing epithelial cell outgrowth juxtaposed to dead dermal substrate for the in vitro expression of keratinocyte cytoplasmic antigens. These antigens were found to be expressed in vitro independently from dermal influences. Their chronology, localization and topography in culture matched the in vivo situation.