Abstract: In order to study the interaction of Malassezia furfur to cultured human keratinocytes,we established a M.furfur keratinocyte co culture system by which the morphologic and functional investigations were combined closely.These were as follows:①The co cultured materials were observed regularly by scanning and transmission electron microscopy.②The effects of the conditioned media on the keratinocyte growth were monitored by a fluorophotometric assay with Alamar blue.③IL 1α and bFGF in the conditioned media were quantitated using ELISA kits.It was found that:①the organisms were adhered to and phagocytized by keratinocytes with a time dependent manner,and the keratinocytes revealed obvious morphologic changes.②the conditioned media could promote growth of keratinocytes,and higher levels of IL 1α and bFGF were detected in the media.③the increased IL 1α and bFGF were secreted from the organism activated keratinocytes rather than from the organisms themselves.The results are helpful to understand why the normal skin flora,M.furfur,could induce various inflammatory skin disorders.

Key words: Malassezia furfur, Keratinocytes, Cell growth, IL-1α, bFGF