Figure 3. GIA effects of anti-PfRH5 IgG in combination with polyclonal antibody specific for other merozoite antigens.

Percentage GIA against the 3D7 parasite clone over increasing concentrations of total purified IgG from rabbits immunized with A) PfRAP3, B) PfMSP1, C) PfAMA1, D) Pf38, E) PfEBA175, F) PfRH2 and G) PfRH4, with (blue line) or without (solid black line) the addition of a fixed low concentration of PfRH5-immunized rabbit IgG (0.156 mg/mL) which, when used alone, gives approximately 25% GIA (dashed black line). Predicted additive effects were calculated according to Bliss independence (see Materials and Methods) and illustrated as the red line on each graph. Data points represent the mean of triplicates from two independent experiments. Bars indicate SEM for all six replicates over two experiments. Asterisks indicate that the predicted and observed values differed significantly (*P<0.05; **P<0.01; ***P<0.001, 2-way ANOVA with Bonferroni post-hoc testing).