Trichothecene mycotoxins depress the mononuclear-phagocytic system of young turkeys

Macrophage cells isolated from the abdominal cavity of 21-day-old turkeys after a single injection of Sephadex suspension were used to quantitate the effects of direct in vitro exposure to deoxynivalenol (DON), 3-acetyldeoxynivalenol (3ac-DON), scirpentriol (STO), or 15-acetylscirpenol (15-MAS). Macrophage monolayers were established on glass surfaces and cells were exposed to graded levels of individual mycotoxins for 1 hour: DON, 20-640 micrograms/microliters of culture; 3ac-DON, STO, 15-MAS, 20-1280 micrograms/microliters of culture. All four mycotoxins caused dose-related effects. A concentration of 50 micrograms/microliter DON caused a significant decrease in macrophage adherence, phagocytosis of opsonized SRBC, and number of opsonized SRBC per macrophage; at 200 micrograms/microliter, phagocytosis of unopsonized SRBC was decreased. There were also increasing percentages of damaged macrophages with increasing DON doses as indicated by morphological alterations. Linear decreases in macrophage viability on exposure to 3-acDON and STO were observed. Moreover, STO and 15-MAS decreased macrophage adherence to glass and 3-acDON, STO, and 15-MAS induced macrophage morphological alterations. This study suggests that trichothecene mycotoxins may be immunosuppressive by affecting viability, adherence and phagocytic potential of mononuclear phagocytic cells of young turkeys.