Effect of the mycotoxin deoxynivalenol on the immune responses of rainbow trout (Oncorhynchus mykiss)

摘要

The trichothecene mycotoxin deoxynivalenol (DON) is commonly found as a natural contaminant in cereals such as wheat, barley, and corn, and exhibits various toxicological effects when present in animal feeds. The effects of DON at a nominal 2 mg/kg feed on immune responses of rainbow trout were investigated, includ- ing relative gene expression of important cytokines (TNF-α, IL-8, IL-1β, IL-10), lysozyme concentration in skin mucus, and level of antigen-specific IgM in blood plasma after vaccination with the commercial vaccine AquaVac ERM containing Yersinia ruckeri type 1 (Hagerman strain). Twenty one-year-old rainbow trout Oncorhynchus myki ss were randomly divided into two groups. The control received a commercial feed with a naturally occurring low level of D ON (225 μg /kg feed), while an experimental group was fed the same formulation with DON added to 1964 μg /kg feed. The trial continued for 23 days. Consumption of feed with added DON showed a significant effect on the immune system, as indicated by a higher level of pro-inflammatory cytokine TNF-α (P < 0.05) and of IL-8 (non-significant) in head kidney. Expression of the pro-inflammatory gene IL-1β and the expression of a gene encoding anti-inflammatory cytokine (IL-10) were not influenced by D ON treatment. Effects on the concentration of skin mucus lysozyme and specific IgM antibody levels were not observed during this experiment. These results suggest that prolonged ingestion of low doses of D ON may influence the immune responses of rainbow trout.