4 beta, 15-Diacetoxyscirpenol induces cytotoxicity and alterations in phagocytic and Fc-receptor expression functions in chicken macrophages in vitro.

4 beta, 15 Diacetoxyscirpenol (DAS) mycotoxin produced by Fusarium species was tested for detrimental effects on macrophage viability, phagocytosis, and Fc-receptor expression. Sephadex-elicited chicken abdominal cells were harvested to establish adherent macrophage monolayers on glass coverslips. Coverslips were then assigned randomly to treatment groups (0, 12.5 and 25 micrograms/mL DAS). Macrophage monolayers were exposed to treatments for 1 h, washed, and tested for various functional endpoints. Treatment with DAS resulted in decreased viability of macrophages (90.8% vs 81.5% vs 70.4% viable in the 0, 12.5 and 25 micrograms treatments, respectively) and decreased the percentage of macrophages phagocytizing sheep erythrocytes (81.6% vs 53.1% vs 46.0%. DAS also caused a decrease in the mean number of opsonized cells engulfed per phagocytic macrophage (5.7 vs 3.7 vs 2.9). A similar trend was observed using unopsonized sheep erythrocytes (15.4% vs 7.6% vs 5.5% phagocytic macrophages and 0.29 vs 0.11 vs 0.08 erythrocytes engulfed per macrophage). The incidence of Fc-receptor positive macrophages determined by sheep erythrocyte rosetting was also decreased in DAS-treated macrophages as compared to the control (49.2% vs 32.7% vs 24.2%). The findings of this study demonstrate that DAS exposure causes a suppression in macrophage phagocytic function and therefore may alter the first line of immunological defense in chickens.