Effect of cianidanol (KB-53) on the activity of mouse cytotoxic-T-lymphocytes.

The effect of cianidanol (KB-53) on the mouse cytotoxic-T-lymphocyte (CTL) activity of the splenic cells was investigated. The CTL activity of the splenic cells prepared from C3H/He, DBA/2 and CBA strain mice which had been sensitized with EL-4 cells were recognized markedly 11 d after the sensitization. The CTL activity showed an antigen specificity. KB-53, in a dose range of 125-1000 mg/kg, augmented the mouse CTL activity in a dose-dependent manner by oral administration once daily for 5 d beginning immediately after the sensitization. This CTL activity disappeared with treatment of the splenic cell with anti-thy-l serum and normal guinea pig serum, therefore, it was confirmed that the cytotoxic activity of the splenic cells which were prepared from the mice sensitized with EL-4 cells depended on the T-cell activity.