FIG 4.

Monoclonal antibodies derived from F1-immunized mice are more effective at neutralizing parasites. (A) Growth of 3D7 and HB3 parasite cultures incubated with 3 mg/ml of the control Ab (purple) or with F1-specific (orange) or F2-specific (blue) antibody for two cycles. The experiment was done three independent times in triplicate, and all data are shown. Significant differences (Table S1) were determined by one-way ANOVA with Dunnett’s multiple-comparison tests. P values were <0.001 (***) and <0.05 (*) for comparisons made to the control. The extents of antibody inhibition for 3D7 and HB3 are 30% and 30% (5G10), 30% and 23% (7E6), 29% and 25% (9G3), 24% and 22% (9D3), 10% and 11% (1B10), 12% and 12% (1G6), 15% and 11% (4B7), and 13% and 13% (4E7), respectively. (B) Additional F1-specific MAbs (3 mg/ml) tested for neutralization of 3D7 and HB3 parasites. The extents of F1 antibody inhibition for 3D7 and HB3 are 26% and 30% (3E3), 28% and 24% (2G10), and 10% and 30% (1E2), respectively. Growth in all antibody-treated cultures (inclusive of control antibody culture) was normalized to that of PBS-treated cultures, since PBS was the vehicle for all antibodies. Significance was determined as described above. P values were <0.001 (***) and <0.05 (*) for comparisons made to the control.