Effect of the Fusarium toxin deoxynivalenol (DON) on IgA, IgM and IgG concentrations and proliferation of porcine blood lymphocytes.

An important effect of the trichothecene mycotoxins is the impairment of the immune function, but immunotoxicity studies have mainly been conducted on the mouse model. In the present study, the effect of deoxynivalenol (DON) on the proliferation of ConA stimulated porcine peripheral blood lymphocytes (PBL) was assessed in vitro after adding of 70-560 ng DON per ml medium, and in vivo after chronic and acute (one single dose) dietary DON exposure (5.7 mg/kg). Immunoglobulin (IgA, IgG, IgM) concentrations were measured by ELISA in supernatants and serum of pigs. The proliferation rate was estimated with two different assays (BrdU incorporation and MTT cleavage). In vitro the ConA stimulated proliferation was inhibited to 50% (IC50) at 200 and 309 ng DON/ml for the BrdU and MTT assay, respectively, indicating a higher sensitivity of DNA synthesis to DON. Immunoglobulin concentrations in the supernatant after in vitro proliferation of PBL with increasing DON concentrations for 72 h were significantly decreased, with IC50 values of 120.6, 84.1 and 71.7 ng DON/ml for IgA, IgM and IgG, respectively. In vivo significant inhibition of lymphocyte proliferation was observed only in the DON acute group using the MTT assay, but values tended to be decreased in the BrdU assay and after chronic DON exposure. Immunoglobulins (IgA, IgM and IgG) in the supernatant of cultured lymphocytes were not significantly affected after dietary DON exposure. Serum IgA of pigs showed no significant differences between the groups, whereas IgM and IgG were significant increased in the DON acute group.