Human epidermal Langerhans cells are more potent than blood monocytes in inducing some antigen-specific T-cell...

The abilities of human epidermal Langerhans cells and peripheral blood macrophages to induce specific T-lymphocyte responses to purified protein derivative (PPD), herpes simplex virus and nickel sulphate were compared. On a cell to cell basis the Langerhans cells were found to be about as potent as adherent cells in inducing T-cell responses to PPD, more potent in inducing responses to herpes simplex virus, and several times more potent in inducing responses to nickel. These data indicate that human epidermal Langerhans cells are highly specialized in antigen presentation, particularly for nickel sulphate. They may play an important role in inducing contact sensitivity dermatitis.