Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C
Sickle hemoglobin (Hb) S and HbC may protect against malaria by reducing the expression of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) on the surface of parasitized red blood cells (RBCs), thereby weakening their cytoadherence to microvascular endothelial cells (MVECs) and impairin...
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th-mahidol.330342018-11-09T09:38:30Z Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C Jeanette T. Beaudry Michael A. Krause Seidina A S Diakite Michael P. Fay Gyan Joshi Mahamadou Diakite Nicholas J. White Rick M. Fairhurst National Institute of Allergy and Infectious Diseases Nuffield Department of Clinical Medicine University of Bamako Faculty of Medicine, Pharmacy and Odonto-Stomatology Mahidol University Agricultural and Biological Sciences Biochemistry, Genetics and Molecular Biology Medicine Sickle hemoglobin (Hb) S and HbC may protect against malaria by reducing the expression of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) on the surface of parasitized red blood cells (RBCs), thereby weakening their cytoadherence to microvascular endothelial cells (MVECs) and impairing their activation of MVECs to produce pathological responses. Therefore, we hypothesized that parasites causing malaria in HbAS or HbAC heterozygotes have overcome this protective mechanism by expressing PfEMP1 variants which mediate relatively strong binding to MVECs. To test this hypothesis, we performed 31 cytoadherence comparisons between parasites from HbAA and HbAS (or HbAC) Malian children with malaria. Ring-stage parasites from HbAA and HbAS (or HbAC) children were cultivated to trophozoites, purified, and then inoculated in parallel into the same wildtype uninfected RBCs. After one cycle of invasion and maturation to the trophozoite stage expressing PfEMP1, parasite strains were compared for binding to MVECs. In this assay, there were no significant differences in the binding of parasites from HbAS and HbAC children to MVECs compared to those from HbAA children (HbAS, fold-change = 1.46, 95% CI 0.97-2.19, p = 0.07; HbAC, fold-change = 1.19, 95% CI 0.77-1.84, p = 0.43). These data suggest that in-vitro reductions in cytoadherence by HbS and HbC may not be selecting for expression of high-avidity PfEMP1 variants in vivo. Future studies that identify PfEMP1 domains or amino-acid motifs which are selectively expressed in parasites from HbAS children may provide further insights into the mechanism of malaria protection by the sickle-cell trait. 2018-11-09T01:45:07Z 2018-11-09T01:45:07Z 2014-03-19 Article PLoS ONE. Vol.9, No.3 (2014) 10.1371/journal.pone.0092185 19326203 2-s2.0-84898618706 https://repository.li.mahidol.ac.th/handle/123456789/33034 Mahidol University SCOPUS https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84898618706&origin=inward |
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Agricultural and Biological Sciences Biochemistry, Genetics and Molecular Biology Medicine Jeanette T. Beaudry Michael A. Krause Seidina A S Diakite Michael P. Fay Gyan Joshi Mahamadou Diakite Nicholas J. White Rick M. Fairhurst Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
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Sickle hemoglobin (Hb) S and HbC may protect against malaria by reducing the expression of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) on the surface of parasitized red blood cells (RBCs), thereby weakening their cytoadherence to microvascular endothelial cells (MVECs) and impairing their activation of MVECs to produce pathological responses. Therefore, we hypothesized that parasites causing malaria in HbAS or HbAC heterozygotes have overcome this protective mechanism by expressing PfEMP1 variants which mediate relatively strong binding to MVECs. To test this hypothesis, we performed 31 cytoadherence comparisons between parasites from HbAA and HbAS (or HbAC) Malian children with malaria. Ring-stage parasites from HbAA and HbAS (or HbAC) children were cultivated to trophozoites, purified, and then inoculated in parallel into the same wildtype uninfected RBCs. After one cycle of invasion and maturation to the trophozoite stage expressing PfEMP1, parasite strains were compared for binding to MVECs. In this assay, there were no significant differences in the binding of parasites from HbAS and HbAC children to MVECs compared to those from HbAA children (HbAS, fold-change = 1.46, 95% CI 0.97-2.19, p = 0.07; HbAC, fold-change = 1.19, 95% CI 0.77-1.84, p = 0.43). These data suggest that in-vitro reductions in cytoadherence by HbS and HbC may not be selecting for expression of high-avidity PfEMP1 variants in vivo. Future studies that identify PfEMP1 domains or amino-acid motifs which are selectively expressed in parasites from HbAS children may provide further insights into the mechanism of malaria protection by the sickle-cell trait. |
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National Institute of Allergy and Infectious Diseases |
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National Institute of Allergy and Infectious Diseases Jeanette T. Beaudry Michael A. Krause Seidina A S Diakite Michael P. Fay Gyan Joshi Mahamadou Diakite Nicholas J. White Rick M. Fairhurst |
format |
Article |
author |
Jeanette T. Beaudry Michael A. Krause Seidina A S Diakite Michael P. Fay Gyan Joshi Mahamadou Diakite Nicholas J. White Rick M. Fairhurst |
author_sort |
Jeanette T. Beaudry |
title |
Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
title_short |
Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
title_full |
Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
title_fullStr |
Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
title_full_unstemmed |
Ex-Vivo cytoadherence phenotypes of Plasmodium falciparum strains from Malian children with hemoglobins A, S, and C |
title_sort |
ex-vivo cytoadherence phenotypes of plasmodium falciparum strains from malian children with hemoglobins a, s, and c |
publishDate |
2018 |
url |
https://repository.li.mahidol.ac.th/handle/123456789/33034 |
_version_ |
1763494958647476224 |