FIGURE 3.

Pb9-specific cells only require 24 h to mediate a protective effect. (A) Pb9⁺ CFSE-labeled splenocytes (3 × 10⁶) from HAd5-MVA TIPeGFP–vaccinated mice were transferred into BALB/c recipient mice 1 d prior (C−1), 1 d after (C+1) or 2 d after (C+2) i.v. challenge with 1000 P. berghei sporozoites (n = 6 per group). Thin blood films were taken from day 5 onward to calculate the percentage of infected RBCs; the graph shows time to 0.5% parasitemia. Data are representative of two independent experiments. (B) Pb9⁺ CFSE-labeled splenocytes from HAd5-MVA TIPeGFP–vaccinated mice were transferred into BALB/c recipient mice 1 d prior to challenge. Mice were injected i.p. with 100 μl of PBS or 0.03 mg/ml FK-506 every morning and evening for the first 2 d postchallenge starting at the time of sporozoite injection (0–48 h) or from 9, 24, or 36 h postinjection (n = 6 per group). Survival curves were analyzed by log-rank (Mantel–Cox) test. An asterisk denotes a significant difference between groups after Bonferoni correction for the number of statistical tests performed on each data set. Data are representative of two independent experiments. *p < 0.05.