Effects of decabrominated diphenyl ether (DBDE) on developmental immunotoxicity in offspring mice

Decabrominated diphenyl ether (DBDE), a representative brominated flame retardant ubiquitous in the environment, is suspected of being hazardous to humans. We evaluated the developmental immunotoxicity of DBDE by an assay system using respiratory syncytial virus (RSV) infection in offspring mice. Pregnant mice were continuously exposed to DBDE (10, 100, 1000, or 10,000 ppm) in the diet from gestation day 10 to weaning on postnatal day 21. Offspring mice born to these dams were intranasally infected with RSV. Virus titers in the lungs of RSV-infected offspring exposed perinatally to DBDE increased dose-dependently compared with the control. The level of interferon-γ in the bronchoalveolar lavage fluids and gene expression of the chemokine RANTES in the lungs were also significantly elevated in offspring mice exposed to DBDE. Histopathological analysis revealed that pneumonia in the lungs of offspring mice exposed to 10,000 ppm of DBDE was exacerbated compared with the control. These results indicate that DBDE is a developmental immunotoxic agent.