ABSTRACT
Phthalate esters, such as di‐(2‐ethylhexyl) phthalate (DEHP), are widespread environmental contaminants. Previously, we have observed that DEHP exacerbates dermatitis elicited by mite antigen in NC/Nga mice. Also, DEHP enhances the functions of bone marrow‐derived dendritic cells (DCs) in vitro. The present study sought to investigate whether phthalate esters affect peripheral blood mononuclear cell (PBMC)‐derived DCs of NC/Nga mice. First, we studied the time course of DC generation from PBMCs and the dose dependency of granulocyte macrophage colony‐stimulating factor and interleukin‐4, and then determined the conditions under which DC differentiation and maturation are moderately induced from PBMCs. Under the conditions determined above, DEHP at 10 μ m significantly inhibited the expression of DC differentiation and maturation markers, such as CD11c, CD40, CD80, CD86 and CD205, whereas mono‐(2‐ethylhexyl) phthalate, a metabolite of DEHP, did not. Furthermore, the effects of DEHP on PBMC‐derived DCs were partially rescued by treatment with ICI 182,780, an estrogen receptor antagonist. Taken together, these results suggest that DEHP can modulate the differentiation and maturation of mouse PBMC‐derived DCs at least partially through activation of the estrogen receptor under our experimental conditions.