REGULATION OF THE LOW AFFINITY IGE FC RECEPTOR (CD23) IN ATOPIC-DERMATITIS

Alterations in the production of CD23, the IgE Fc receptor, may play a role in the etiology of atopic dermatitis and other allergic conditions. Interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and interferon-alpha (IFN-alpha) are involved in coordinate regulation of CD23. IL-4 stimulates production of both CD23 and IgE. IFN-gamma also stimulates production of CD23, but suppresses production of IgE and inhibits IL-4-mediated production of CD23. IFN-alpha also suppresses these IL-4-mediated activities and, in addition, suppresses IFN-gamma-mediated stimulation of CD23 production. Changes in this coordinate regulation may be involved in the development of atopic dermatitis. Expression of CD23 by Langerhans cells is stimulated by IL,4 and IFN-gamma. Further, levels of CD23-positive T cells are elevated in atopic dermatitis subjects as compared to non-atopic controls, and observed skin changes appear to be related to changes in CD23-positive mononuclear cell populations. Coordinate regulation of CD23 by IFN-gamma and IL-4 may also be important in other allergic conditions, parasitic infections, and a variety of disease states.