ABSTRACT
Melanocytes grown in the pure monolayer culture lack the three-dimentional organization and the cellular interactions that exist in vivo. These can be partially overcome by growing melanocytes together with other epidermal cells in cultured skin equivalent models. In this study, skin equivalents were prepared by seeding mixtures of cultured human keratinocytes and melanocytes in ratio 10 : 1 onto artificially constructed dermis. They were cultured in DMEM/F12 (1 : 1) for 4 days and then lifted to the air-liquid interface and maintained in DMEM/F12 (3 : 1) for 10 days. Histological and electronmicroscopic examinations of the cultured skin equivalants revealed a structure that closely resembled human interfollicular epidermis; 1. Melanocytes, were identified by positive staining with melanoma-specific antibodies (NKI/C3 and S-100 protein) and prominent cytoplasm with rich cell organelles, were located in the basal layer. 2. Melanocytes contained predominently early stage melanosomes and prominent Golgi apparatus. Mature melanins, were usually abundant in normal skin, were hardly seen both in melanocytes and in neighbouring keratinocytes. 3. Melanocytes were surrounded by keratinocytes but did not form intercellular junctions with them. 4. Keratinocytes were charaterized by microfilament bundles and intercellular junctions such as desmosomes and hemidesmosomes with neighbouring keratinocytes and artificial dermis. The melanocyte in the above skin equivalents had a strong resemblance to the one of normal human skin and therefore this model can be used as artificial skin for the transplantation and in the investigation of melanocytes' role to the UV stimuli.