Effects of phthalate esters on dendritic cell subsets and interleukin-4 production in fluorescein isothiocyanate-induced contact hypersensitivity.

Phthalate esters with short alkyl chains, such as di-ethyl (DEP), di-n-propyl (DPP), and di-butyl phthalate (DBP), have adjuvant effects on an FITC-induced contact hypersensitivity mouse model. The adjuvant effects of DPP and DBP are associated with enhanced trafficking of FITC-presenting CD11b(+) dendritic cells (DC). DEP has relatively weak activity as to FITC-positive cell migration. Here we demonstrated that DBP and DPP also increased the number of FITC-positive CD8alpha(+) DC in draining lymph nodes. We also found enhanced production of interleukin-4 in draining lymph nodes after FITC sensitization with DEP, DPP, or DBP, suggesting an additional adjuvant mechanism of phthalate esters.