IL-2 enhances the antitumor activity of Fv-ζ⁺ T cells in vivo.

Five C57BL/6 mice per group were injected ip with 10⁴huCD3-EL4 lymphoma cells. The recipient mice received either tumor cells alone (■) or tumor and IL-2 (▪), 10⁷Fv-ζ–negative T cells plus IL-2 (○), 10⁷Fv-ζ–negative T cells repeatedly (●),10⁷Fv-ζ⁺ T cells (▵), 10⁷ Fv-ζ⁺T cells plus IL-2 (▴), or 10⁷ Fv-ζ⁺ T cells repeatedly (▿). When exogenous IL-2 was given, each animal was injected with 80 000 U/d during the first week of the experiment. When repeated injections were performed, 10⁷ T cells were injected a second time at day 6.