Pr antigens in the skin: distinct localization linked to the stage and the type of keratinocyte differentiation.

Pr antigens (Pr ags), glycoconjugates of the red blood cell surface, have been traced in stratified squamous epithelia (SSE) with homogeneous and serologically monospecific monoclonal antibodies. Pr ags were expressed either at the plasma membrane level or within the cytoplasm of the keratinocytes (associated with the cytoskeleton). Pr ags were expressed in the basal cells. The distribution within this germinative compartment was in accordance with the concept of a cellular heterogenicity in the basal cell layer. A neuraminidase resistant Pr ag was retained in the maturing compartment of epithelia undergoing parakeratotic differentiation (including psoriatic epidermis). Monoclonal cold agglutinins may serve as new markers for the study of glycoconjugates in keratinocytes during normal and pathological differentiation.