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.

活的人皮肤等同物，其中人角质形成细胞在含有人真皮成纤维细胞的胶原基质上培养，已经成功地移植并在免疫缺陷小鼠的深层结缔组织上维持很长时间。在此，我们将人毛乳头细胞培养在I型胶原凝胶中，并与原代培养的人表皮细胞和少量黑素细胞作为复合移植物，研究了来自人毛囊的人毛乳头细胞对免疫缺陷小鼠异种移植复合移植物诱导毛囊的影响。在移植后三周，表皮细胞产生人表皮样组织。组织学检查显示，没有观察到表皮延长或新形成的毛囊样结构。有趣的是，在原代表皮细胞培养物中最初伴随的大量DOPA阳性黑素细胞不仅在表皮基底层中发现，而且在整个真皮中层中发现，而使用人成纤维细胞代替毛乳头细胞将复合移植物移植到免疫缺陷小鼠体内，仅在基底层存在少量黑素细胞。这些结果表明，人毛乳头细胞在复合移植物的异种移植中使黑素细胞的维持或迁移成纤维。

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.