Recent Advances in Mast Cell Biology

Mast cells (MCS) are not simple trouble makers in immediate allergic hypersensitivity, but play various important biological roles in host defense as well as tissue remodeling after infl ammation such as wound healing and fi brosis. Since heterogeneity exists in human MCS, human skin type MCS should be used for dermatological research. A large number of pure human skin type MCS which satisfy all characteristics of cutaneous MCS have been established from human dispersed skin in the absence of serum under the stimulation of stem cell factor. However, biological roles of human MCS should be investigated in vivo and human MC development in mice after xenotransplantation of human hematopoietic stem cells is confi rmed. Both human cutaneous and mucosal type MCS can develop in immunodefi cient NOG mice with identical distribution pattern to human body. This model may provide a potential tool for the in vivo investigation of human MC functions. More recently, we have established embryonic stem cell-derived MCS which may suggest a unique embryonic pathway for early development of cutaneous MCS. Further investigations on MC biology should be encouraged to elucidate the mechanism of human skin diseases leading to the development of new drugs in dermatology. (Dermatol Sinica 27: 7984, 2009)