Expression of immune relevant genes in pigs under the influence of low doses of deoxynivalenol (DON).

Deoxynivalenol (DON) is one of the most common Fusarium toxins in animal feed and poses a potential risk especially for monogastric animals like pigs. DON is known to modulate the immune system, dependent on dose and frequency of exposure. The aim of the study was to investigate the effects of chronic exposure to low levels of DON on the expression of immune relevant genes. In a feeding trial (84 days), 20 pigs were assigned equally to a control and a treatment group. The DON-content of the contaminated diet was 1.2 mg/kg from day 1 to 41, from day 42 it was elevated to 2.0 mg/kg. The control group (n = 10) was fed a diet with a DON concentration lower than 0.05 mg/kg. Blood samples were taken over the course of the study and ileum samples were taken at slaughter. Gene expression measurement was done using real-time RT-qPCR. For target genes, those cytokines were chosen, which were estimated to be implicated in the modulation of the immune system induced by DON ingestion. In ileum, significant down-regulations could be observed for IL-1β and IL-8 (p < 0.05). Most significant regulations in blood could be detected on day 45 after increasing the dietary DON content in the experimental diet. Herein, down-regulations of IL-1β, IL-8 and TNFα were demonstrated. In conclusion, the present study provides data concerning chronic application of DON in low doses, as little is known in this area. Down-regulations of immune-related transcription factors and pro-inflammatory immune factors could be demonstrated.