Figure 3.

OT-I T cells expressing caIL-12 displayed enhanced tumor regression without evidence of toxicity. OT-I or P14 transgenic T cells transduced to express the constructs indicated in the figure legends and were administered to mice bearing established, subcutaneous B16-OVA tumors. All mice received 550-cGy whole-body irradiation. Cells (5×10⁶) were administered by intraperitoneal injection. isIL-12 served as a positive control for systemic IL-12 exposure. Data shown are from one experiment that was independently repeated. The effects of the isIL-12 construct are shown in A and C; the effects of the isIL-12 construct are shown in b and d. (A, B) Serial tumor measurements were obtained after treatment. N=5 mice per group. Error bars represent the standard error of the mean. P values represent statistical comparisons between the two groups indicated on each graph using matched-pairs, repeated-measures two-way ANOVA tests. (C, D) The change in body weight relative to baseline is shown. Error bars show the standard error of the mean. (E) Serum IL-12 levels and (F) serum IFN-γ levels were determined on day 10 after treatment. The cytokines were measured with a multiplex cytokine kit. Values for individual mice are plotted.; ANOVA, analysis of variance; caIL-12, constitutive anchored interleukin-12; cGFP, constitutively expressed green fluorescent protein; IFN-γ, interferon- γ; isIL-12, inducible secreted interleukin-12.