Enrichment of human epidermal Langerhans cells by attachment to erythrocyte monolayers.

The present investigation introduces a method for purification of human epidermal Langerhans cells (LC). The method is based on the attachment of LC to IgG-coated sheep erythrocyte monolayers via their Fc receptors. To optimize the enrichment assay, several variables were tested. The best results were obtained when epidermal cells were centrifuged against erythrocyte monolayers; the purification procedure was performed at 4 degrees C in the presence of 5% fetal calf serum, using about 6 X 10(6) epidermal cells per erythrocyte plate (diameter 5 cm). The average purity of the recovered LC was 80.9% and LC-depleted fractions contained an average of 0.5% DR-positive cells. LC were able to enhance significantly leukoagglutinin- and purified protein derivative-induced T lymphocyte proliferation and leukocyte migration inhibitory factor production.