FIG. 2.

(a) BALB/c mice received TCR-Tg CD8⁺ T cells isolated from WT or IFNγKO mice and were immunized with 2 × 10⁶ PFU VV-CS. Eight days later, mice were challenged with 3.5 × 10⁴ P. yoelii sporozoites and parasite-specific rRNA levels in the liver determined by quantitative RT-PCR. (b) Mice received WT or IFNγKO TCR-Tg CD8⁺ T cells and were immunized as described for panel a. Eight days later, 2 × 10⁶ purified TCR-Tg CD8⁺ spleen cells were recovered and retransferred into secondary naive BALB/c hosts that were subsequently challenged with 3.5 × 10⁴ P. yoelii sporozoites. The parasite load in the liver was evaluated as for panel a. Each bar represents a single mouse. A Student t test was used to evaluate statistical significance.