TRICHOTHECENE MYCOTOXINS DEPRESS THE MONONUCLEAR-PHAGOCYTIC SYSTEM OFYOUNG TURKEYS

Macrophage cells isolated from the abdominal cavity of 21-day-old turk eys after a single injection of Sephadex suspension were used to quant itate the effects of direct in vitro exposure to deoxynivalenol (DON), 3-acetyldeoxynivalenol (3ac-DON), scirpentriol (STO), or 15-acetylsci rpenol (15-MAS). Macrophage monolayers were established on glass surfa ces and cells were exposed to graded levels of individual mycotoxins f or 1 hour: DON, 20 - 640 mu g/mu l of culture; 3ac-DON, STO, 15-MAS, 2 0 - 1280 mu g/mu l of culture. All four mycotoxins caused dose-related effects. A concentration of 50 mu g/ml DON caused a significant decre ase in macrophage adherence, phagocytosis of opsonized SRBC, and numbe r of opsonized SRBC per macrophage; at 200 mu g/ml, phagocytosis of un opsonized SRBC was decreased. There were also increasing percentages o f damaged macrophages with increasing DON doses as indicated by morpho logical alterations. Linear decreases in macrophage viability on expos ure to 3-acDON and STO were observed. Moreover, STO and 15-MAS decreas ed macrophage adherence to glass and 3-acDON, STO, and 15-MAS induced macrophage morphological alterations. This study suggests that trichot hecene mycotoxins may be immunosuppressive by affecting viability, adh erence and phagocytic potential of mononuclear phagocytic cells of you ng turkeys.