Glutamate signaling through the kainate receptor enhances human immunoglobulin production

CD23 is implicated as a regulator of IgE synthesis. A soluble form of CD23 (sCD23) is released following cleavage by ADAM10 and enhanced sCD23 is correlated with increased IgE. In the CNS, signaling through the kainate receptor (KAR) increases ADAM10. In B cells, activation of KARs produced a significant increase in ADAM10 and sCD23 release as well as an increase in B cell proliferation and immunoglobulin production. In addition, ADAM10 inhibitors reduce IgE synthesis from in vitro cultures of human B cells. Thus, we report for the first time the unique presence of the kainate receptor in B cells and that activation of KARs could serve as a novel mechanism for enhancing B cell activation.