Journal: PLOS Pathogens
Article Title: Elevated Plasmodium falciparum sexual conversion in HbAC and HbAS red blood cells in naturally infected malaria patients
doi: 10.1371/journal.ppat.1014542
Figure Lengend Snippet: (A) Microscopy-based quantification of parasite stages (rings, trophozoites and schizonts) expressed as percentages of a total of 100 counted parasites per sample. Y-axis: percentage of parasite stages (%); X-axis: HBB genotype groups (HbAA n = 1, HbAC n = 1 and HbAS n = 2, and HbSS n = 2 and HbSC n = 2 donors from a malaria-endemic area in Nanoro, Burkina Faso. Timepoints shown are where progression toward late stages ( i.e., schizont stages) is most clearly observed, namely 35–40 hpi (Generation 0; left graph and Generation 1; right graph). A shift towards earlier parasite stages indicates developmental delay.(B) Developmental progression of individual parasite cultures across timepoints 35–40 hpi (Generation 0), and 25–30 hpi and 35–40 hpi (Generation 1), shown as the proportion of late stages (schizonts) among total infected RBCs (iRBCs) measured by flow cytometry. Data are stratified by HBB genotype: HbAA ( n = 5), HbAC ( n = 5),HbAS ( n = 4), and HbSC ( n = 1) donors from a malaria-endemic area in Nanoro, Burkina Faso; and HbSS ( n = 12), HbSC ( n = 1) and n = 6 control HbAA donors [HbAA CTRL] from a non-endemic area. (C) Representative flow cytometry plots showing the gating strategy for the detection of late parasite stages. Left: total RBCs gated. Right: within the total RBCs gate in left plot, uninfected RBCs (uRBCs) and iRBCs are identified, with iRBCs further gated into early and late parasite stages by Hoechst 33342. Abbreviations: CTRL, control sample; FSC-A, Forward Scatter-Area; G0, Generation 0; G1, Generation 1; GLMs, Generalized linear models; Hb, hemoglobin; HBB, human hemoglobin beta; Hpi, hours post-invasion; RBCs, red blood cells; SSC-A, Side Scatter-Area; Timepoint abbreviations are specified in the figure legend.
Article Snippet: Samples for flow cytometry analysis (using a CytoFLEX LX flow cytometer, Beckman Coulter) were prepared by resuspending parasite cultures (1:3) in PBS containing 1% BSA, followed by staining with Hoechst 33342 (1:500, BD Pharmingen) in a final volume of 100 μl per well.
Techniques: Microscopy, Parasite, Infection, Flow Cytometry, Control
![(A) Microscopy-based quantification of parasite stages (rings, trophozoites and schizonts) expressed as percentages of a total of 100 counted parasites per sample. Y-axis: percentage of parasite stages (%); X-axis: HBB genotype groups (HbAA n = 1, HbAC n = 1 and HbAS n = 2, and HbSS n = 2 and HbSC n = 2 donors from a malaria-endemic area in Nanoro, Burkina Faso. Timepoints shown are where progression toward late stages ( i.e., schizont stages) is most clearly observed, namely 35–40 hpi (Generation 0; left graph and Generation 1; right graph). A shift towards earlier parasite stages indicates developmental delay.(B) Developmental progression of individual parasite cultures across timepoints 35–40 hpi (Generation 0), and 25–30 hpi and 35–40 hpi (Generation 1), shown as the proportion of late stages (schizonts) among total infected RBCs (iRBCs) measured by flow cytometry. Data are stratified by HBB genotype: HbAA ( n = 5), HbAC ( n = 5),HbAS ( n = 4), and HbSC ( n = 1) donors from a malaria-endemic area in Nanoro, Burkina Faso; and HbSS ( n = 12), HbSC ( n = 1) and n = 6 control HbAA donors [HbAA CTRL] from a non-endemic area. (C) Representative flow cytometry plots showing the gating strategy for the detection of late parasite stages. Left: total RBCs gated. Right: within the total RBCs gate in left plot, uninfected RBCs (uRBCs) and iRBCs are identified, with iRBCs further gated into early and late parasite stages by Hoechst 33342. Abbreviations: CTRL, control sample; FSC-A, Forward Scatter-Area; G0, Generation 0; G1, Generation 1; GLMs, Generalized linear models; Hb, hemoglobin; HBB, human hemoglobin beta; Hpi, hours post-invasion; RBCs, red blood cells; SSC-A, Side Scatter-Area; Timepoint abbreviations are specified in the figure legend.](https://pub-med-central-images-cdn.bioz.com/pub_med_central_ids_ending_with_3122/pmc13623122/pmc13623122__ppat.1014542.g003.jpg)