The effects of dermal papilla cells from human hair on the induction of hair follicle after xenotransplantation of the composite graft into immunodeficiet nu-SCID mice.

在含有人真皮成纤维细胞的胶原基质上培养人角质形成细胞的活的人皮肤等量物，已经成功地移植并长期维持在免疫缺陷小鼠的深层结缔组织上。在这里，我们在I型胶原凝胶中培养人真皮乳头细胞，并在原代培养的人表皮细胞上覆盖少量黑色素细胞作为复合移植物。我们研究了从人毛囊中提取的人真皮乳头细胞对免疫缺陷小鼠异种移植后毛囊诱导的影响。移植后3周，表皮细胞生成人表皮样组织。组织学检查未见表皮伸长或新形成的滤泡样结构。有趣的是，在初代表皮细胞培养中，不仅在表皮基底层发现了大量DOPA阳性的黑素细胞，而且在整个真皮中也发现了大量的黑素细胞，而在免疫缺陷小鼠中，用人成纤维细胞代替真皮乳头细胞移植复合移植物时，只在基底层发现了少量黑素细胞。这些结果表明，在异种复合移植物移植中，人真皮乳头细胞对黑色素细胞的维持或迁移起着控制作用。

Living human skin equivalents, in which human keratinocytes are cultured on collagen matrix containing human dermal fibroblasts, have been successfully transplanted and maintained for a long time on deep connective tissue of immunodeficient mice. Here, we cultured human dermal papilla cells in the type I collagen gels and overlayed by primary culture of human epidermal cells concomitant with a few melanocytes as a composite graft.We examined effects of human dermal papilla cells derived from human hair follicle on the induction of hair follicle after xenotransplantation of the composite grafts into immunodeficient mice. At three weeks after transplantation, the epidermal cells generated human epidermis-like tissue. Histological examinations revealed that no epidermal elongation or newly formed follicular-like structure were observed. Interestingly, a significant number of DOPA positive melanocytes, which were initially concomitant in a primary epidermal cell culture, was found not only in the epidermal basal layer but also in the entire mid-dermis, while the transplantation of a composite grafts in immunodeficient mice by using human fibroblasts instead of dermal papilla cells showed the presence of a small number of melanocytes in the basal layer only.These results indicates that human dermal papilla cells fascillitate the maintenance or migration of the melanocytes in the xenotransplantation of composite grafts.