Fig. 5.

Synergistic effects of IL-18 with IL-2, IL-7 or IL-15 in the proliferative responses of IEL were assessed in the absence (a) or presence (b) of 5 ng/ml anti-CD3 MoAb. IL-18 alone did not induce IEL proliferation, but with the combination of stimuli IL-18 with IL-2, IL-7 or IL-15 increased the proliferative responses of IELs compared with the stimulation of IL-2, IL-7 or IL-15 alone. *P < 0·05, treatment versus medium alone (none), **P < 0·05, treatment versus IL-18 alone. The results are representative of three experiments.