Figure 3.

Effect of the deletion of Tregs on the induction of CTLs. The CTL activity in the Treg-depleted group, 1% Treg-added group and 5% Treg-added group was assessed based on the cytolytic activity against the autologous tumor cell line, L1023L, 4 weeks after MLTC. The CTL activity against L1023L cells was successfully induced by autologous RLNLs in the Treg-depleted group. By contrast, the addition of Tregs at 1 and 5% following depletion completely inhibited the induction of CTL activity. Tregs, regulatory T cells; CTL, cytotoxic T lymphocyte; E/T ratio; effector cells/target cell ratio; MLTC, mixed lymphocyte-tumor cell culture; RLNL, regional lymph node lymphocyte.