Effects of T2 toxin on DNA polymerases and terminal deoxynucleotidyl transferase of Molt4 and Nu8 cell lines.

T2-toxin effects on [3H]TdR incorporation, polymerase alpha and beta terminal deoxynucleotidyl transferase, and thymidine kinase activities of two thymus derived cell lines, Molt4 and Nu8, have been measured. T2-toxin, which specifically affects the immune system, inhibits [3H]TdR incorporation at doses of 0.1-10ng/ml. With regard to enzymatic activities, at doses of T2 toxin of 0.1-1 ng/ml a transient enzymatic increase is observed. In contrast, for T2-toxin concentrations greater than 1 ng/ml, alpha polymerase and TdT activities of Nu8 cells are also inhibited. These inhibitions account for the already described effects of T2 toxin and, in particular, the impaired DNA and protein synthesis.