Human Skin and Hair Xenografted on SCID Mouse. Usefulness as an in vivo Experimental Model.

Abstract

To develop new in vivo study system of human skin and hair, our research group has tried to produce hu-skin/SCID mice model, that is, mice xenografted with human skin or hair suitable for in vivo experiments. We found that SCID mice and nude-scid mice were good recipients of full-thickness and split-thickness skin grafts from humans. The latter mice seemed to be better, because their hairless nature was convenient for experimental procedures and shrinkage rate of the grafts was relatively small in them. The atypical keratinocytes were well survived in the grafts on the mice when lesional skin of Bowen's disease or solar keratosis was transplanted. In contrast, Paget cells of extramammary Paget's disease were almost completely eliminated from the grafts. Melanocytes of melanoma in situ were maintained only in epidermis of the grafts on nude-scid mice. Carcinogenesis experiments using various kinds of chemical carcinogens failed to produce tumors in human skin grafted on SCID mice, though many tumors developed in the control mouse skin. Hair growth was observed in the human scalp skin transplanted on SCID mice. An isolated human hair follicle obtained by dissection of scalp skin was successfully transplanted onto SCID mice and used to identify localization of stem cells of hair follicles. In conclusion, hu-skin/SCID mice system surely provides us with a very useful in vivo study system of human skin and hair.