Figure 4. Starch-bound antigens elicit immune responses and reduce parasitemia after P. berghei challenge.

The Giemsa stained thin smears of red blood cells isolated from mice vaccinated with starch containing wild type GBSS (negative controls), challenged with P. berghei ANKA and analyzed after 3 weeks post infection. The red arrows indicate that the mice were highly infected with P. berghei (a). The Giemsa stained thin smears of red blood cells isolated from mice vaccinated with starch containing both GBSS-PbAMA_1-C and GBSS-PbMSP_1-19, challenged with P. berghei ANKA and analyzed after 3 weeks post infection (b). The Giemsa stained thin smear of red blood cells isolated from mice vaccinated with starch containing both GBSS-PbAMA_1-C and GBSS-PbMSP_1-19, challenged with P. berghei ANKA and analyzed after 6 weeks post-infection (c). Note the presence of numerous leukocytes (probably neutrophils, green arrows) and fewer infected red blood cells (red arrows) in the vaccinated mice after 3 weeks post-infection (b). Both leukocytes and P. berghei infected red blood cells were not detected in mice, which survived after 6 weeks post-infection (c). Western blots of total extracts of antigens prepared from red blood cells infected by P. berghei. The immunoblots were incubated with the immune sera isolated from 4 mice immunized with starch containing wild type GBSS (panel d, lanes 1-4). Blots probed with immune sera of 4 mice immunized with starch containing GBSS-PbAMA_1-C (panel e, lanes 1–4). Lane f corresponds to the blots incubated with the positive rabbit polyclonal antibodies specific to P. berghei AMA1 produced in E. coli.