Abstract
Morphologic events associated with immunologic rejection by strain 13 guinea pigs of dinitrophenylated epidermal cells (DNP-EC) were studied, light microscopically. The DNP-EC injection site in the skin of normal animals exhibited clusters of EC with a moderate amount of inflammatory infiltrate composed of neutrophils and mononuclear cells throughout the dermis. Marked proliferation of EC was observed in skin lesions obtained 3 days after the intradermal injection. The EC contained keratohyaline granules. In case of the 5 day site, central keratinization of the proliferated EC had occurred and cysts were evident. Typical delayed-type skin reactions associated with EC necrosis and extensive inflammatory infiltrate including increase in the number of basophilic leukocytes was elicited 7 days after the injection. The implantation of haptenated epidermal cells is considered to be a useful approach when attempting to analyse histologically the course of contact sensitivity from sensitization phase to elicitation.
