Expression of basement membrane zone antigens at the dermo-epibolic junction in organ cultures of human skin.

Using the epithelial outgrowth in organ cultures of human skin ("epiboly") as a model system for basement membrane zone neogenesis, the emergence of various antigenic determinants of the junction zone (bullous pemphigoid antigen, type IV collagen and laminin) was studied and the time sequence of their appearance assessed. All 3 antigens were found at the newly built dermo-epibolic junction; their synthesis, however, followed a distinct time sequence: bullous pemphigoid antigens emerged synchronously with the advancing tip of the migrating epithelium, whereas type IV collagen and to a greater extent, laminin, appeared with considerable delay. At the ultrastructural level, the formation of basal lamina accompanied the emergence of type IV collagen and laminin.