Ciliary neurotrophic factor preferentially enhances spontaneous IgE production by B cells from atopic patients

The effect of ciliary neurotrophic factor (CNTF) on IgE production by purified B cells from atopic patients was studied. CNTF significantly enhanced spontaneous IgE production by B cells from patients with atopic eczema/dermatitis syndrome (AEDS) in a dose-dependent fashion, and maximum enhancement was achieved at 1 ng/ml. CNTF-induced enhancement of IgE production was blocked by anti-CNTF mAb or anti-gp 130 mAb, but not by anti-IL-6 mAb. On the other hand, CNTF did not significantly enhance spontaneous production of IgGl, IgG2, IgG3, IgG4, IgM, IgAl or IgA2 by B cells from AEDS patients. In contrast to B cells from AEDS patients, B cells from non-atopic subjects failed to produce IgE spontaneously, and CNTF did not induce IgE production by non-atopic subjects' B cells. B cells from atopic patients contained surface IgE positive B cells (sIgE+ B cells), which spontaneously produced IgE, while surface IgE negative B cells (sIgE- B cells) failed to do so. CNTF enhanced IgE production by sIgE+ B cells from patients with AEDS, allergic rhinitis or bronchial asthma, while CNTF failed to induce IgE from sIgE- B cells from these patients. Stimulation of sIgE- B cells with IL-4 plus anti-CD40 mAb induced IgE production. However, stimulation of sIgE- B cells with CNTF plus IL-4, or CNTF plus anti-CD40 mAb did not induce IgE production by sIgE- B cells. Collectively, these results indicate that CNTF preferentially enhanced spontaneous IgE production by post-switched sIgE+ B cells, while CNTF failed to induce IgE by pre-switched sIgE- B cells. These results suggest that CNTF may be involved in the allergic diseases.