EFFECTS OF TRICHOTHECENE STRUCTURE ON CYTOKINE SECRETION AND GENE-EXPRESSION IN MURINE CD4(-CELLS() T)

The effects of trichothecene structure on cytokine secretion and gene expression were assessed in primary CD4(+) T-cells from murine spleen. CD4(+) T-cells were stimulated with concanavalin A (Con A) for 2 or 7 days in the presence of various concentrations of the trichothecenes, vomitoxin (VT or deoxynivalenol), nivalenol (NIV), 15-acetyl deoxyniv alenol (15-ADON), 3-acetyl deoxynivalenol (3-ADON), T-2 toxin (T-2) an d verrucarin A (Ver A). Culture supernatants were subsequently analyze d for interleukin (IL)-2, IL-4 and IL-5 by ELISA. At day 2, all tricho thecenes were found to have inhibited production of IL-2, IL-4, and IL -5. However, at day 7, supernatant IL-2 was significantly increased (2 -5.5-fold) in cultures containing VT, NIV, 3-ADON, and 15-ADON at 250, 250, 2500, and 1000 ng/ml doses, respectively, when compared to contr ol Con A-stimulated cultures; significant increases in IL-2 were not o bserved with T-2 and Ver-A. Similarly, at day 7, IL-4 and IL-5 were si gnificantly increased in the presence of VT (100 ng/ml), NIV (100 ng/m l), 3-ADON (1000 ng/ml), 15-ADON (500 ng/ml), T-2 (1 ng/ml), and Ver A (50 pg/ml, only IL-5) when compared to control cultures. IL productio n was inhibited at trichothecene concentrations exceeding the aforemen tioned optima. When total RNA of 2-day cultures was assessed by revers e transcriptase polymerase chain reaction (RT-PCR) in conjunction with Southern analysis, IL-2 mRNA was also found to be superinduced by VT (50 and 100 ng/ml), NIV (50, 100 and 250 ng/ml), 3-ADON (1500 ng/ml), 15-ADON (100 ng/ml), T-2 (0.5 ng/ml) and Ver A (25, 50 and 100 pg/ml); IL-4 mRNA by VT (50 ng/ml), NIV (50 ng/ml), and Ver A (25, 50 and 100 pg/ml); IL-5 mRNA by VT (50 ng/ml); and IL-6 mRNA by 15-ADON (100 ng/ ml) and Ver A (50 pg/ml). As the trichothecene concentration increased from these levels, inhibition of mRNA transcript levels was also obse rved for many of the interleukins. Taken together, the results suggest that trichothecenes as a group can either inhibit or superinduce both IL secretion and mRNA levels in CD4(+) T-cells. Superinduction exhibi ted a rank order of macrocyclic > type A > type B trichothecenes and w as dependent on acylation of the trichothecene nucleus.