Immunosuppressive properties of deoxynivalenol.

The immunosuppressive effect of deoxynivalenol (DON) was investigated in male Balb/c mice. The effect of the route of DON administration to the animals was first studied. The results showed that DON acted efficiently on the immune system per os. The administration of 100 ppm DON in the diet caused the death of all the animals within a few days. After oral administration of DON to mice, liver and kidney weights were not changed while the thymus weight was significantly reduced at concentrations greater than 10 ppm. The spleen weight was reduced less than the thymus weight. Histologically, the structure of the thymus was damaged and the high doses produced an atrophy of this organ. Serum levels of anti-sheep red blood cells (SRBC) antibodies were significantly reduced, this effect was dose-dependent. The stimulation of B and T cells by mitogens was depressed: the mitogenic responses were more reduced for thymic cells than for splenic cells. DON inhibited cellular proliferation in vitro, as estimated by [3H]thymidine incorporation:murine splenocytes were more sensitive (IC50 = 131 ng/ml of culture) than XP human fibroblasts (IC50 = 252 ng/ml of culture).