Studies on Human Epidermal Langerhans Cells

Human epidermis was separated from dermis by means of a suction blister device and dissociated with trypsin. The epidermal cell suspensions obtained contained 3–5% Langerhans cells as judged by immunofluorescence staining of the cells with a rabbit anti‐DR antiserum. The epidermal cells were co‐cultured with purified allogeneic T cells and with autologous T cells with or without PPD of tuberculin. A strong T‐cell response to allogeneic epidermal cells was obtained, as was a strong T‐cell response to PPD, provided autologous epidermal cells were also present. Pre‐treatment of the epidermal cells with anti‐DR antiserum plus complement abolished both these responses. These data indicate that epidermal cells are able to substitute for macrophages both in the allo‐activating and in the antigen‐presenting function. Since the responsible cells were DR‐positive, it is highly probable that the cells responsible for these functions are the Langerhans cells.