Associated expression of CD1 antigen and Fc receptor for IgE on epidermal Langerhans cells from patients with atopic dermatitis.

The presence of Fc receptors for IgE on epidermal Langerhans cells (LC) from patients with atopic dermatitis (AD) was demonstrated by three different types of experiments. Firstly, cell-bound IgE on LC was removed by acid elution and restored by highly purified human myeloma IgE (IgE kappa). Secondly, after pepsin digestion of cell-bound IgE the number of LC staining with anti-human light chain (kappa, lambda) antibodies significantly decreased in contrast to the number of LC staining with anti-human epsilon heavy chain antibody. Thirdly, LC formed rosettes with sheep red blood cells (SRBC) coated with IgE kappa. Epidermal LC from normal non-atopic controls, did not form rosettes with SRBC-IgE. The SRBC-IgE rosette formation could be inhibited by preincubation with IgE kappa and BB10 (MoAb directed against the Fc receptor for IgE on human eosinophils, platelets and macrophages), but also with human IgG, whereas the SRBC-IgG rosette formation could be inhibited neither by IgE kappa nor by BB10. Both the SRBC-IgE and the SRBC-IgG rosette formation could be inhibited by OKT6 (anti-CD1) antibody. The results of inhibition studies with OKT6 antibody on the reconstitution of IgE on epidermal LC after acid elution suggest an associated expression of the CD1 antigen and the Fc receptor for IgE.