Uptake of the naturally occurring 3-alpha-hydroxy isomer of T-2 toxin by a murine B cell hybridoma

The uptake of the naturally occurring 3-alpha-hydroxy isomer of T-2 toxin (alpha-T-2 toxin) was investigated in a murine B cell hybridoma as a model for trichothecene-lymphocyte interactions. alpha-[3H]T-2 toxin was prepared by oxidation of T-2 toxin and reduction with [3H]NaBH4 followed by normal phase and reverse phase high-performance liquid chromatography. Uptake of alpha-[3H]T-2 toxin by hybridoma cells was both time- and concentration-dependent. The antibiotic anisomycin inhibited uptake of alpha-[3H]T-2 toxin by hybridoma cells, which suggests ribosomal involvement in the uptake mechanism. Uptake of alpha-[3H]T-2 toxin was also inhibited by verrucarin A, roridin A and deoxynivalenol, and the inhibition followed a trichothecene structure-activity rank similar to that established for protein synthesis inhibition and in vivo toxicity. The characteristics of uptake of alpha-[3H]T-2 toxin by isolated splenocytes were qualitatively similar to those of the hybridoma but accumulation at equilibrium was less. Accumulation of alpha-[3H]T-2 toxin by erythrocytes, cells lacking ribosomes, did not increase with time and was not affected by the presence of unlabelled toxin. The results suggested that specific accumulation and uptake of alpha-[3H]T-2 toxin by the murine B cell hybridoma and spleen cells were highly consistent with a model based on intracellular binding of T-2 toxin to ribosomes.