Figure 7
The effect of immunotherapy on the mean volumes (+SEM) of CEA positive and CEA negative human tumors that were established in nude (NU/J Foxn1nu) mice (see figure 6). Groups of five mice were injected once with 107 tumor cells (day 0). On d28 well-established tumors (e.g. see figure 6) were treated by a single intravenous injection of 107 normal PBLs (
) or 107 PBLs transduced using a retroviral vector containing either a CEA-specific scFv-CD28-zeta-GFP chimeric receptor (
) or a GFP gene alone (
). The CEA-specific T-bodies caused unexpectedly startling regression colon tumors 4 weeks after systemic administration of T-bodies (** p < 0.01). Control cells had little effect. The effect was specific for CEA as CEA- (COLO 320) cells were not affected by any cells transferred. By day 58, all mice had died from the tumor (cross) except those treated with the CEA-specific T-body. Despite 100% survival of T-body treated mice on day 58, all groups (treated and untreated) had succumbed to the tumor by 100 days.