Figure 5. CPS immunization elicits heterologous blood-stage immunity.
Mice were CPS immunized three times (i1, i2, i3) under chloroquine (CQ) cover by P. chabaudi AS-infected mosquito bites or mock immunized with uninfected mosquito bites, and challenged (C) 96–107 days later by mosquito bite. Erythrocytic parasitemia was evaluated daily by quantitative RealTime PCR for blood-stage parasites (cycle 1–3, displayed as parasitized erythrocytes (pE) per ml whole blood) and from cycle 3–20 by thin blood-film (expressed as % parasitized erythrocytes [parasitemia], 0.01% parasitemia corresponds to 1,000,000 pE per ml). (A/B) Heterologous challenge with P. chabaudi CB infected mosquitoes (A) Parasitemia between 1st and 3rd (n = 10) and (B) from 3rd to 20th erythrocytic cycle (n = 20). (C/D) Homologous challenge with P. chabaudi AS-infected mosquitoes (C) Parasitemia between 1st and 3rd (n = 10) and (D) from 3rd to 20th erythrocytic cycle (CPS immunized n = 20, mock immunized n = 19). (E) Total AUC comparing mock and CPS immunized mice receiving heterologous or homologous mosquito bite challenge. Data are presented as mean ± SEM, (A–D) Mann–Whitney test per time point (E) Kruskal Wallis with Dunn's multiple comparisons test *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.