Successive generation of antigen-presenting, dendritic cell lines from murine epidermis

Dendritic cells are specialized APCs that exhibit an extraordinary capacity to activate naive T cells. Langerhans cells (LC), as epithelial tissue-specific members of this family, play key roles in the induction of T cell-mediated immunity against environmental, infectious, and tumor- associated Ags in skin. A major limitation in studying the biology of dendritic cells or LC has been the absence of stable, long-term cell lines. To overcome this limitation, we have established a series of APC lines (XS series) from newborn BALB/c mouse epidermis. XS lines, which have grown for more than 12 mo in culture, exhibit high similarity to LC freshly procured from skin in terms of: a) tissue of derivation (epidermis), b) phenotype (la(low)/CD45⁺/E-cadherin⁺/B7-1^-), c) shape (elongated dendrites), and d) Ag-presenting profile (modest ability to activate naive, allogeneic T cells and remarkable ability to present a protein Ag to primed CD4⁺ T cells). The availability of XS lines as well as the methodologies used for their growth enhance our capability of studying the biology of LC at biochemical and molecular levels.