Immune responses induced by SEA. SEA induces M2 differentiation of macrophages and prevents toll-like receptor-dependent activation of dendritic cells, which is correlated with reduced production of inflammatory cytokines. Dendritic cells also induce the differentiation of CD4⁺ T cells into the Th2 subset through a CD40-dependent mechanism. SEA can also activate Th2 CD4⁺ T cells and regulatory B cells. Regulatory B cells, once activated, secrete IgE and further stimulate basophil production of IL-4 and IL-13, which then induce Th2 CD4⁺ T cells. Th2 CD4⁺ T cells can release various Th2 cytokines such as IL-4, IL-5, IL-10, and IL-13, shifting the overall immunity into a Th2-dominant response.