Effects of environmentally relevant concentrations of 2,3,7,8-TCDD on domestic chicken immune function and CYP450 activity: F1 generation and EGG injection studies

Domestic chickens (Gallus gallus) were used as a surrogate species for wild turkey to assess risk from environmental 2,3,7,8-TCDD exposure. Lymphocyte proliferation and CYP450 induction were assessed in adults exposed via i.m. injection, in F1 14-day old hatchlings, in F1 adults (30-weeks old), and in 14-day old hatchlings exposed via yolk sac injections. Hatchlings from injected eggs exhibited a dose-response in lymphocyte proliferation, IgM titers, EROD, and PROD endpoints. Exposed adults showed a significant dose-dependent increase in CYP450 induction. F1 14-day old chicks exhibited a significant dose-dependent suppression of B-cell proliferation and induction of CYP450 enzymes. F1 adult proliferative responses exhibited B-cell suppression, that was not statistically significant. Significant sex-dependent EROD and MROD induction was also observed in F1 adults, indicating mixed-function oxidase imprinting from maternal exposure.