Expression of low-affinity receptor for IgE (Fc epsilon RII, CD23) and IgE-BF (soluble CD23) release by lymphoblastoid B-cell line RPMI-8866 and human peripheral lymphocytes of normal and atopic donors.

The low-affinity receptor for IgE (CD23) as well as the soluble IgE-binding factors (IgE-BF, sCD23) are important factors in IgE antibody regulation. The CD23 expression and the concomitant release of CD23 were analysed from the lymphoblastoid B-cell line RPMI-8866 and from peripheral blood lymphocytes (PBL) of healthy volunteers as well as atopic patients. CD23 expression and sCD23 release of RPMI-8866 cells were dependent on the stage of culture. While CD23 expression decreased with increasing time of culture (Day 1-3), the sCD23 release was enhanced during the culture period. Cytokines such as IL-4, IL-2, TNF alpha and IFN-gamma exerted various effects on the target cells depending on the culture period. CD23 expression on normal lymphocytes was lower compared with the expression on atopic cells. Lymphokines (IL-2, IL-4) as well as mitogens (PHA, Con A) enhanced CD23 expression and IgE-BF (sCD23) release. The degree of enhancement was always higher with atopic cells compared with the results obtained with cells of normal donors.