Fc gamma-receptors on Langerhans' cells and keratinocytes in suspension from normal skin characterized using soluble immune complexes and monoclonal antibodies

Abstract

Fc-receptors for IgG (FcR) on epidermal cells in suspension were studied using soluble immune complexes and monoclonal antibodies (MoAbs) against FcR I, FcR II and FcR III using an indirect immunofluorescence technique. The binding of immune complexes demonstrated that most Langerhans' cells (greater than 95%) and a proportion of keratinocytes (25 +/- 6%) expressed functional FcR activity. The reactivity with MoAbs showed that epidermal cells possess different types of FcR. Langerhans' cells reacted only with IV.3 (anti-FcR II/-CDw32). A varying percentage of keratinocytes reacted with 32.2 (anti-FcR I/-CD64) (18 +/- 10%), Leu 11b (anti-FcR III/-CD16) (19 +/- 6%) and B1D6 (against a placental FcR) (35 +/- 8%). Both with immune complexes and MoAbs the staining was strongest along the cell surface, but cytoplasmic staining was also regularly present. The data add further support to the contention that keratinocytes have an immune function. FcR on epidermal cells may play an immunoregulatory role interacting with isotypes and cytokines in the skin. Keratinocyte-produced soluble FcR could also be an immunological mediator.