Figure 3: Replacement of iron-deficient RBCs with iron-replete RBCs increases P. falciparum infection. | Nature Communications

Figure 3: Replacement of iron-deficient RBCs with iron-replete RBCs increases P. falciparum infection.

From: Host iron status and iron supplementation mediate susceptibility to erythrocytic stage Plasmodium falciparum

Figure 3

(a,b) P. falciparum (strain 3D7) infection of reticulocytes (CD71+) and mature RBCs (CD71−) from an IDA+Fe donor. (a) Bars represent the percent of parasitized reticulocytes (CD71+) and mature RBCs (CD71−). Error bars represent the s.d. *P<0.0001. (b) Contribution of parasitized reticulocytes (CD71+) and parasitized mature RBCs (CD71−) to the total infection. Error bars represent the standard deviation. (c) Growth rate of P. falciparum in RBC populations in which IDA RBCs were replaced with IR RBCs. RBCs were inoculated individually or together in the same wells at different ratios (100% IDA; 90% IDA and 10% IR; 75% IDA and 25% IR; 50% IDA and 50% IR; 25% IDA and 75% IR; 100% IR) and subsequently infected. Elongated triangles below the x axis represent the percentage of IDA RBCs (white triangle) and IR RBCs (grey triangle) in the total RBC population. Bars represent parasite growth rates after one 96 h growth assay. Error bars represent the s.d. *P<0.01 and **P<0.0003. (d and e) Invasion rate of P. falciparum into RBC populations in which IDA RBCs were replaced with IR RBCs. Differentially labelled RBC donors were inoculated individually or together in the same wells at different ratios (100% IDA; 90% IDA and 10% IR; 80% IDA and 20% IR; 50% IDA and 50% IR; 20% IDA and 80% IR; 10% IDA and 90% IR; 100% IR). Each invasion condition contained 20 × 106 total RBCs. (d) Bars represent parasite invasion rate. Elongated triangles below the x axis represent the percentage of IDA RBCs (white triangle) and IR RBCs (grey triangle) in the total RBC population. Error bars represent the s.d. *P<0.001, compared with P. falciparum invasion rate into 100% IR RBCs. (e) Number of invasions events into IDA (diamonds) and IR (circles) RBCs as the frequency of each increases. Linear regression was used to determine the best fit lines for the data (IR R2=0.9842 and IDA R2=0.9305). Analysis of covariance was performed to compare the slopes of the lines and calculated P<0.0001. The null hypothesis was no difference between the two RBC types (H0: βIron replete=βIron deficient, α=0.05) n.s., nonsignificant.

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