CD23 EXPRESSION ON B-LYMPHOCYTES AND ITS MODULATION BY CYTOKINES IN ALLERGIC PATIENTS

The aim of this study was to assess the expression of CD23 on peripher al blood B-cells, and its in vitro modulation by recombinant human int erferon-gamma (IFN-gamma) in phytohaemagglutinin- (PHA) or recombinant human interleukin-4 (IL-4)-stimulated cultures in atopic patients wit h Dermatophagoides pteronyssinus hypersensitivity and in healthy non-a topic subjects. Atopic patients with asthma not receiving allergen-spe cific immunotherapy (n = 21) were studied and further compared with a group of atopic subjects with asthma under allergen-specific immunothe rapy (n = 21). They were age-(+/5 yr) and sex-matched. The results wer e also compared with those obtained in the non-atopic group (n = 11). CD23 expression on B-lymphocytes and its modulation were analysed by f low cytometry using conjugated monoclonal antibodies with a double imm unofluorescence method. Atopic patients had an increase in the percent age of B-cells expressing CD23 in peripheral blood. Phytohaemagglutini n and IL-4 induced a rise in the percentage of CD23-positive B-cells i n both atopic groups and non-atopic subjects. Phytohaemagglutinin prov oked an increase in the intensity of CD23 expression on B-cells from s timulated cultures in all groups, while IL-4 only produced a significa nt increase in atopic patients. The presence of IFN-gamma decreased th e CD23 expression on B-cells in PHA-stimulated culture of atopic patie nts, whereas it caused an increase in CD23 expression in the non-atopi c group. Furthermore, the presence of IFN-7 in IL-4-stimulated culture s induced a decrease in CD23 expression on B-cells in all cases. These results indicate a difference between atopic and non-atopic donors in their responses to IL-4 and IFN-gamma. On the other hand, allergen-sp ecific immunotherapy did not induce any shift in the expression and mo dulation of this receptor.