Effect of various reagents on the susceptibility of target cells to the cytotoxicity of guinea pig lymphotoxin (GLT).

The cytotoxic activity of guinea pig lymphotoxin (GLT) was increased when the target cells were treated with the following metabolic inhibitors: puromycin, actinomycin D, NaN3, NaF, and 2,4-dinitrophenol, whereas calf serum, N-acetyl-D-galactosamine, colchicine, and vinblastin inhibited GLT-cytotoxicity. Puromycin, an inhibitor of protein synthesis, exhibited the most potent enhancing effect on GLT-cytotoxicity. It seems likely that there are certain cellular metabolic processes depending on cellular protein synthesis which antagonize GLT-cytotoxicity. Taking advantage of this effect of puromycin, a time-saving assay method for GLT-cytotoxicity was developed.