IMMUNOPHENOTYPIC ANALYSIS OF NORMAL HUMAN DENDRITIC CELLS ISOLATED FROM EPIDERMIS AND DERMIS

Background The skin immune system comprises two types of dendritic cel ls, i.e. CD1a-positive Langerhans cells in the epidermis and CD36-posi tive dendritic macrophages in the dermis. Dendritic cells can migrate from skin explants into a culture medium. Methods We have examined the morphology and immunophenotype of the dendritic cells migrating from epidermal and dermal sheets in vitro. The epidermis and dermis of kera tomes of normal human skin were separated with dispase and cultured fo r 72 h. At this time, the non-adherent cells in the medium were remove d, enriched on a metrizamide or Lymphoprep gradient, counted, prepared by cytospin, and labeled for CD1a, CD36, and HLADr. Results Cells mig rating from the epidermis and dermis show many thin projections or a f ew veils from the cell surface. Approximately four times more cells mi grate from epidermal than dermal sheets from the same keratome. Conclu sions Using methods to separate the epidermis from the dermis, both CD 1a-positive Langerhans cells and CD36-positive dendritic macrophages c an be obtained from both tissues, although in different numbers.