Structure/function studies of T-2 mycotoxin with a monoclonal antibody.

A BALB/C murine monoclonal antibody (mAb) specific for the trichothecene mycotoxin T-2 was previously generated. The anti-T-2 antibody, designated HD11, can detect T-2 in the nanogram range employing an enzyme-linked immuno-sorbent assay. The HD11 antibody at a concentration of 1 microgram/ml completely protected against the T-2-induced cytotoxicity of the human epidermoid carcinoma cell lines Hep-2 and KB. Fine specificity analysis was performed using 10 structurally related T-2 metabolites to inhibit the specific binding of HD11 to T-2 mycotoxin. The results suggest a binding specificity of the protective HD11 antibody for the bulky hydrophobic alkyl side chain at position R5 and the acetyl groups at positions R2 and R3 of the T-2 mycotoxin molecule. HD11 anti-T-2 mAb, which bound to the T-2 metabolite acetyl T-2 (with a substituted acetyl group at R1 position), efficiently neutralized its in vitro cytotoxicity. On the other hand, the cytotoxicity of T-2 metabolites neosalaniol and 3' OH HT-2, both of which lack the alkyl side chain at position R5 and which did not bind to HD11, was unaffected by HD11.