Figure 6

Plasmodium falciparum -infected DRAG mice elicit specific antibodies and self-cure blood stage infection. A) DRAG mice (n = 18) were challenged with P. falciparum sporozoites as in Figure 4 and followed for blood stage parasitaemia by PCR and blood smears. All mice were infected by day 28 post-challenge but mice self-cured the infection by day 45 post-challenge. B) Spleen cells from infected DRAG mice (day 28 post-challenge) were stimulated in vitro with protein extracts of P. falciparum infected red blood cells (Pf-iRBCs) for 2 days or left unstimulated and analysed by FACS using anti-human CD3, CD4, CD8, TNF, and IFNγ. Numbers on the histograms represent frequencies of TNF and IFNγ positive cells among gated human CD4 and CD8 T cells from pooled mice (n = 3). C) Titers of human IgM (left panel) and IgG (right panel) antibodies to Pf-iRBCs using IFA slides coated with synchronized rings and trophozoites/schizonts. Data represent antibody titers in mice analysed individually at day 28 post-challenge. Fourteen out of 18 infected DRAG mice (closed circles) elicited specific antibodies, whereas uninfected DRAG mice (n = 5) did not have specific antibodies (open circles).