LAUSR

The environmental hazards of arsenic (As) and copper (Cu) contamination have swept through quite a few districts worldwide. Whereas, molecular mechanisms involved in As- and Cu-induced immunotoxicity in Gallus gallus bursa of Fabricius (BF) are complex and elusive. Male Hy-line chickens were exposed to arsenic trioxide (As2O3; 30 mg/kg) and copper sulfate (CuSO4; 300 mg/kg) alone or in combination, respectively, to examine the potential ecotoxicity of them. The ions homeostasis and BF index of chicken had distinct changes after As or/and Cu exposure. Moreover, As or/and Cu treatment significantly increased the MDA content and NOS activity, and simultaneously resulted in reductions in CAT and AHR activities. Subsequently, it was further exhibited up-regulations of nuclear factor-κB (NF-κB), inflammatory mediators and pro-inflammation cytokines accompanied by depletion of anti-inflammatory cytokines and severe pathological conditions. Moreover, decreased ratio of IFN-γ/IL-4 and increased level of IL-17 illustrated an imbalance of the immune response. Meanwhile, incremental mRNA transcription and protein levels of heat shock proteins (HSPs) alleviated toxicity caused by As or/and Cu. Importantly, exposure to both contaminants significantly soared the BF injury in comparison with exposure to As or Cu alone. All these results illustrated that exposure to As2O3 or/and CuSO4 elicited BF tissue damage and ions changes, and its severity was associated with prolonged persistence of oxidative damage, accompanied by a dysregulated immune response which played a vital role in inflammatory injury. Additionally, combined management of As2O3 and CuSO4 could exacerbate BF injury.