Figure 6. GIA synergies with mixtures of rabbit antisera and mouse monoclonal antibodies.

Percentage GIA against 3D7 and FVO parasites using increasing gradients of concentrations of IgG from rabbits immunized with PfRH4 (Panels A–C) or PfEBA175 (Panel D) with (blue line) or without (solid black line) the addition of a fixed low concentration of either an anti-basigin mAb (TRA-1-85, 1 µg/mL) or anti-PfRH5 mAb (QA5, 10 µg/mL) which, when used alone, give approximately 15–25% 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. Results are mean of two independent experiments for the anti-PfRH4/TRA-1-85 mixture with the 3D7 parasite clone, and one experiment for the other combinations. All measurements were done in triplicate. Bars indicate SEM for all replicates. Asterisks indicate the predicted and observed values differed significantly (** P<0.01; ***P<0.001; 2-way ANOVA with Bonferroni post-hoc testing).