A nice review about the early non-T-cell source of IL-4 from basophils that act as Th2-inducing antigen-presenting cells. Even though we have shown that during LN responses to alum-precipitated antigens IL-4 is dispensable for the early induction of Th2-features including B cell maturation and helper T cell differentiation more, it is important to keep in mind that the basophil-source of IL-4 may have implication during the clearance of helminth infections and the development/maintenance/ augmentation of allergic diseases by induction of IgE production, activation of mast cells and basophils, as well as eosinophilic inflammation. An important role for basophils is unquestionable for they have been shown (together with mast cells) to release large amounts of IL-4 and IL-13 after cross-linkage of their IgE receptor, Fce receptor I (FceRI), by complexes of antigen plus antigen-specific IgE. However, recent evidence has proposed a novel role in antigen presentation to CD4 T cells that could play major part to induce/augment their commitment towards Th2 CD4 T cells.
Role of basophils during the initiation/augmentation of Th2 immune responses