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.

将人角质形成细胞培养在含有人真皮成纤维细胞的胶原基质上的活体人皮肤替代物已成功地移植到免疫缺陷小鼠的深层结缔组织上并保持了较长时间。在此，我们将人毛乳头细胞在I型胶原凝胶中培养，并在原代培养的人表皮细胞和少量黑素细胞的基础上进行复合移植，观察了人毛囊来源的人毛乳头细胞在免疫缺陷小鼠异种移植后诱导毛囊生长的作用。在移植后三周，表皮细胞产生了人的表皮样组织。组织学检查未见表皮延长或新形成的滤泡样结构。有趣的是，最初伴随在原代表皮细胞培养中的大量DOPA阳性黑素细胞不仅在表皮基底层而且在整个真皮中都被发现，而免疫缺陷小鼠用人成纤维细胞而不是真皮乳头细胞进行复合移植物移植时，仅在基底层存在少量的黑素细胞。这些结果表明，在复合移植物的异种移植中，人毛乳头细胞成束地维持或迁移黑素细胞。

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.