Effects of PfRH5 and PfCyRPA antibodies upon the efficiency with which merozoites convert into ring or pseudo-ring stage parasites shown in S4 Fig.

Table A, Egress to start of spinning. Table B, Duration of spinning. Table C, End of spinning to first pseudopod visible. Table D, Pseudopod first visible to pre-ring formation. Table E, Pre-ring formation to complete ring formation. (XLSX)</p

Live cell video of <i>Plasmodium falciparum</i> merozoites egressing from schizont in the presence of Cy.007 Fab at 400 μg/mL.

No merozoite invasions were observed and most extracellular merozoites did not change during the 10 minute imaging period. Video playback is 10x live imaging speed. (AVI)</p

Live cell video of <i>Plasmodium falciparum</i> merozoites egressing from schizont in the presence of R5.008 IgG at 40 μg/mL.

Successful invasions are indicated with white arrows and black arrows indicate selected extracellular merozoites that begin to differentiate into pseudo-rings beginning about 5 minutes and 40 seconds after egress. Video playback is 10x live imaging speed. (AVI)</p

Effects of PfRH5 and PfCyRPA antibodies upon parasite invasion efficiency shown in Fig 2.

Table A, Number of contacts per egress. Table B, Number of invasions per egress. Table C, % contacts that invade. Table D, % of invasions that regress. Table E, Productive invasions per egress. Table F, % of productive invasions per contact. (XLSX)</p

Live cell video of <i>Plasmodium falciparum</i> merozoites egressing from schizont in the presence of R5.004 IgG at 22 μg/mL.

There are no erythrocyte invasions observed and black arrows indicates selected extracellular merozoites that begin to differentiate into pseudo-rings about 3 minutes after egress. Video playback is 10x live imaging speed. (AVI)</p

The effects of anti-PfRH5 and PfCyRPA antibodies on the differentiation of intracellular and extracellular merozoites into ring-stage parasites.

(A-C) The ability of the antibodies to stimulate or inhibit the differentiation of intracellular, extracellular and regressed merozoites into (A) early, (B) pre-ring and (C) complete ring-stage parasites was assessed from observing live cell imaging videos of Plasmodium falciparum parasites. Full antibody names and concentrations (μg/mL) are indicated below bottom graph. Each event is represented with a symbol and bars indicate the median. Statistical analyses were performed using unpaired t tests in GraphPad Prism V 9.0. The asterisks indicate where parasite mAbs have altered the number of events significantly from the EBL 040 intracellular or extracellular control (arrows) with *p<0.05, **p<0.01 and ***p<0.001. (D) Diagram summarizing the effects of the anti-PfRH5 and -PfCyRPA antibodies on ring differentiation for intracellular and extracellular merozoites.</p

Quantification of the effects of antibodies to PfRH5 and PfCyRPA upon the invasion of RBCs by <i>Plasmodium falciparum</i> 3D7 merozoites.

Video microscopy of several merozoite egress events was observed in the presence of antibodies with concentrations in μg/mL indicated in brackets. (A) The times from egress to first contact indicate were not significantly different indicating the imaging conditions were consistent. (B) The degree of deformation of merozoites on erythrocyte surfaces was quantified according to [20] in the presence of antibodies. R5.004-(22) caused significantly less deformation than the control or parasite antibodies using chi-squared analysis. (C-G) The timings of other invasion stage as indicated on the y-axes were measured using the antibody combinations names and concentrations (μg/mL) indicated below the x-axes. Antibody 9 is Cy.007 Fab-(400). Each event measured is represented by a symbol with bars indicating the median. Statistical analyses were performed using unpaired t tests in GraphPad Prism V 9.0. The asterisks indicate where parasite mAbs have altered the number of events significantly from the EBL 040 control with *p (TIF)</p

Parasite specific mAbs to PfRH5 and PfCyRPA inhibit <i>Plasmodium falciparum</i> invasion of human RBCs.

(A-F) Several live cell videos of P. falciparum merozoites egressing and attempting to invade erythrocytes in the presence of each of the antibodies (concentrations and combinations indicated) were analyzed. The number of successful events is presented for each parameter indicated by the y axis. Full antibody names and concentrations (μg/mL) are indicated below bottom graphs. Each event is represented by a symbol and bars indicate the median number of events (A,B,E) or the percentage of events (C,D,F). Statistical analyses were performed using unpaired t tests in GraphPad Prism V 9.0. The asterisks indicate where parasite mAbs have altered the number or percentage of events significantly from the EBL 040 control with *p<0.05, **p<0.01 and ***p<0.001.</p

Live cell video of <i>Plasmodium falciparum</i> merozoites egressing from schizont in the presence of Cy.009 IgG at 60 μg/mL.

No successful invasions were detected and the extracellular merozoites were observed to spin and begin to differentiate into pseudo-rings about 4 minutes after egress. Video playback is 10x live imaging speed. (AVI)</p

Effects of PfRH5 and PfCyRPA antibodies upon parasite invasion events shown in S2 Fig.

Table A, Egress to first contact. Table B, Deformation score of % total interaction. Table C, End of deformation to end of invasion. Table D, Start of echinocytosis to end of echinocytosis. Table E, Start of echinocytosis to maximum echinocytosis. Table F, Duration of maximum echinocytosis. Table G, Maximum echinocytosis to end of echinocytosis. (XLSX)</p