Enrichment of unlabeled human Langerhans cells from epidermal cell suspensions by discontinuous density gradient centrifugation.

In this report we introduce an alternative procedure for enrichment of human epidermal Langerhans cells (LC) from epidermal cell suspensions of normal skin. By means of discontinuous Ficoll-Metrizoate density gradient centrifugation, a fraction containing high numbers of viable, more than 80% pure LC was recovered, as judged by CD1a expression. The purity of the LC-enriched fraction appeared to be dependent on the percentage LC in the crude epidermal cell suspension. LC enriched by this method retained their accessory and antigen-presenting capacities, as determined in the Concanavalin-A induced T-cell response, in the allogeneic mixed leukocyte reaction and in the antigen-specific T-cell proliferation assay in vitro. The great advantage of this method is that it is simple and rapid and that the isolated LC are unlabeled.