FIG. 5.

Trypomastigote-induced parasitemia and mortality in mice immunized with p154/13, pΔ154/13, and pcDNA3. BALB/c mice were immunized with p154/13, pΔ154/13, or pcDNA3. Three weeks after the last immunization, mice were challenged i.p., with 6,500 bloodstream trypomastigotes. (A) Course of infection, with the mean values obtained from eight mice ± the standard deviations. At the peak of infection (day 8), the parasitemia of mice immunized with each plasmid were compared. The results were as follows: (i) p154/13 versus pcDNA3, P < 0.001; (ii) p154/13 versus pΔ154/13, P = 0.011; (iii) pΔ154/13 versus pcDNA3, P > 0.05. (B) Kaplan-Meier curves for survival of eight mice immunized with the indicated plasmid. Statistically significant survival was observed in mice immunized with p154/13 compared to animals that received pΔ154/13 or pcDNA3 (P < 0.05). The number of mice immunized with pΔ154/13 or pcDNA3 that survived infection was not significantly different (P > 0.05).