Enhanced production of IgE anti-Japanese cedar pollen specific antibodies by peripheral blood B cells from patients with Japanese cedar pollinosis.

BACKGROUND IgE antibodies against Japanese cedar pollen (JCP) play an important role for the pathogenesis of the cedar pollinosis, but the mechanism of their production has been unclear. We explored the capacity of peripheral blood B cells from pollinosis patients to produce anti-JCP specific IgE. METHODS Peripheral blood B cells from 16 pollinosis patients and 9 normal subjects were cultured with mitomycin-C treated T cells with immobilized anti-CD3 for 10 days. RESULTS B cells from pollinosis patients produced higher amounts of anti-JCP specific IgE than those from normal subjects upon stimulation with immobilized anti-CD3 activated autologous T cell, whereas the production of anti-JCP specific IgM were comparable between normal subjects and patients. Exogenous IL-4/IL-5 or anti-CD3 stimulated patients' T cells could not induce the production of anti-JCP specific IgE from normal B cells. CONCLUSIONS These results indicate that B cells from normal individuals contain comparable numbers of precursors that are committed to produce anti-JCP specific IgM to patients' B cells. Moreover, the data confirm that the class switching of IgM to IgE within anti-JCP specific B cells contributes to development of Japanese cedar pollinosis.