Secreted IgD Amplifies Humoral T Helper 2 Cell Responses ...
The function of IgD has been mysterious. Shan et al. find that IgD recognized food antigens and targeted basophils through galectin-9. IgD ligation by antigen induced basophil secretion of IL-4, IL-5, and IL-13, which amplified Th2 cell-mediated IgG1 and IgE production by B cells. IgD also constrained IgE-mediated basophil degranulation.