Effects of sodium selenite on the decreased percentage of T cell subsets, contents of serum IL-2 and IFN-γ induced by aflatoxin B₁ in broilers.

Aflatoxin B1 (AFB1), especially inducing hepatocellular carcinoma and immunosuppression of animals, poses a serious healthy and economic hazard to both humans and livestock. Animal studies have demonstrated that selenium (Se) provides anticarcinogenic and antimutagenic effects against AFB1. However, the effects of Se against AFB1-induced immunosuppression were rarely reported. To test this, three hundred 1-day-old male avian broilers were divided into five groups and fed on control diet (0.4 mg/kg Se), AFB1 group(0.3mg/kg AFB1+0.4 mg/kg Se), AFB1+Se group I(0.3mg/kg AFB1+0.6 mg/kg Se), AFB1+Se group II(0.3mg/kg AFB1+0.8 mg/kg Se) and AFB1+Se group III(0.3mg/kg AFB1+1.0mg/kg Se) for 21 days (n=60/group). Although the body weight in AFB1 group was lower than that in control group at 14 days of age, there no significant differences on body weight among five groups at 7 and 21 days of age. No evident clinical symptoms were observed among five groups from 7 to 21 days of age. The percentages of peripheral blood CD3(+), CD3(+)CD4(+), CD3(+)CD8(+) and the contents of serum IL-2 and IFN-γ in AFB1 group were decreased, compared with those in control group. Compared with those in AFB1 group, the percentages of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells in three AFB1+Se groups were increased from 14 to 21 days of age, and the contents of serum IL-2 and IFN-γ in all AFB1+Se groups were increased from 7 to 21 days of age. On the contrary, the percentages of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) T cells, and the contents of Serum IL-2 and IFN-γ in AFB1+Se group III were lower than those in AFB1+Se group II. It was concluded that 0.6 and 0.8 mg/kg Se could increase the decreased percentages of peripheral blood T-cell subsets and the contents of serum IL-2 and IFN-γ induced by 0.3mg/kg AFB1 in the diets, and cellular immune function could be improved in chickens.