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Thiam LG, Nyarko PB, Ansah F, Niang M, Awandare GA, Aniweh Y. Phenotypic characterization of Ghanaian P. falciparum clinical isolates reveals a homogenous parasite population. Front Immunol 2022; 13:1009252. [PMID: 36211335 PMCID: PMC9537689 DOI: 10.3389/fimmu.2022.1009252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 09/06/2022] [Indexed: 01/26/2023] Open
Abstract
Background Erythrocyte invasion by P. falciparum involves functionally overlapping interactions between the parasite's ligands and the erythrocyte surface receptors. While some P. falciparum isolates necessarily engage the sialic acid (SA) moieties of the erythrocytes during the invasion, others use ligands whose binding is independent of SA for successful invasion. Deciphering the major pathway used by P. falciparum clinical isolates represent a key step toward developing an efficient blood stage malaria vaccine. Methods We collected a total of 156 malaria-infected samples from Ghanaian children aged 2 to 14 years and used a two-color flow cytometry-based invasion assay to assess the invasion phenotype diversity of Ghanaian P. falciparum clinical isolates. Anti-human CR1 antibodies were used to determine the relative contribution of the PfRh4-CR1 interaction in the parasites invasion phenotype and RT-qPCR was used to assess the expression levels of key invasion-related ligands. Results Our findings show no clear association between demographic or clinical data and existing reports on the malaria transmission intensity. The complete invasion data obtained for 156 isolates, showed the predominance of SA-independent pathways in Ghanaian clinical isolates. Isolates from Hohoe and Navrongo had the highest diversity in invasion profile. Our data also confirmed that the PfRh4-CR1 mediated alternative pathway is important in Ghanaian clinical isolates. Furthermore, the transcript levels of ten invasion-related genes obtained in the study showed little variations in gene expression profiles within and between parasite populations across sites. Conclusion Our data suggest a low level of phenotypic diversity in Ghanaian clinical isolates across areas of varying endemicity and further highlight its importance in the quest for new intervention strategies, such as the investigation of blood-stage vaccine targets, particularly those targeting specific pathways and able to trigger the stimulation of broadly neutralizing invasion antibodies.
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Affiliation(s)
- Laty G. Thiam
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Prince B. Nyarko
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Felix Ansah
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Makhtar Niang
- Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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Thiam LG, Ansah F, Niang M, Awandare GA, Aniweh Y. Short-term cryopreservation and thawing have minimal effects on Plasmodium falciparum ex vivo invasion profile. Front Cell Infect Microbiol 2022; 12:997418. [PMID: 36204649 PMCID: PMC9531135 DOI: 10.3389/fcimb.2022.997418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
Ex vivo phenotyping of P. falciparum erythrocyte invasion diversity is important in the identification and down selection of potential malaria vaccine targets. However, due to the lack of appropriate laboratory facilities in remote areas of endemic countries, direct processing of P. falciparum clinical isolates is usually not feasible. Here, we investigated the combined effect of short-term cryopreservation and thawing processes on the ex vivo invasion phenotypes of P. falciparum isolates. Ex-vivo or in vitro invasion phenotyping assays were performed with P. falciparum clinical isolates prior to or following culture adaptation, respectively. All isolates were genotyped at Day 0 for parasite clonality. Subsequently, isolates that were successfully culture-adapted were genotyped again at Days 7, 15, 21, and 28-post adaptation. Invasion phenotyping assays were performed in isogenic isolates revived at different time points (3, 6, and 12 months) post-cryopreservation and the resulting data were compared to that from ex-vivo invasion data of matched isogenic parental isolates. We also show that short-term culture adaptation selects for parasite clonality and could be a driving force for variation in invasion phenotypes as compared to ex vivo data where almost all parasite clones of a given isolate are present. Interestingly, our data show little variation in the parasites' invasion phenotype following short-term cryopreservation. Altogether, our data suggest that short-term cryopreservation of uncultured P. falciparum clinical isolates is a reliable mechanism for storing parasites for future use.
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Affiliation(s)
- Laty G. Thiam
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Felix Ansah
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Makhtar Niang
- Pôle Immunophysiopathologie et Maladies Infectieuses, Institut Pasteur de Dakar, Dakar, Senegal
| | - Gordon A. Awandare
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
- Department of Biochemistry Cell and Molecular Biology, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
| | - Yaw Aniweh
- West African Centre for Cell Biology of Infectious Pathogens, College of Basic and Applied Sciences, University of Ghana, Accra, Ghana
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Thiam F, Diop G, Coulonges C, Derbois C, Mbengue B, Thiam A, Nguer CM, Zagury JF, Deleuze JF, Dieye A. G6PD and HBB polymorphisms in the Senegalese population: prevalence, correlation with clinical malaria. PeerJ 2022; 10:e13487. [PMID: 35811813 PMCID: PMC9266585 DOI: 10.7717/peerj.13487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 05/03/2022] [Indexed: 01/24/2023] Open
Abstract
Background Host genetic factors contribute to the variability of malaria phenotypes and can allow a better understanding of mechanisms involved in susceptibility and/or resistance to Plasmodium falciparum infection outcomes. Several genetic polymorphisms were reported to be prevalent among populations living in tropical malaria-endemic regions and induce protection against malaria. The present study aims to investigate the prevalence of HBB (chr11) and G6PD (chrX) deficiencies polymorphisms among Senegalese populations and their associations with the risk for severe Plasmodium falciparum malaria occurrence. Methods We performed a retrospective study with 437 samples, 323 patients recruited in hospitals located in three different endemic areas where malaria episodes were confirmed and 114 free malaria controls. The patients enrolled were classified into two groups: severe malaria (SM) (153 patients) and uncomplicated malaria (UM) (170 patients). PCR and DNA sequencing assessed host genetic polymorphisms in HBB and G6PD. Using a multivariate regression and additive model, estimates of the impact of human HBB and G6PD polymorphisms on malaria incidence were performed. Results Six frequent SNPs with minor allele frequencies (MAF) > 3% were detected in the HBB gene (rs7946748, rs7480526, rs10768683, rs35209591, HbS (rs334) and rs713040) and two in the G6PD gene (rs762515 and rs1050828 (G6PD-202 G > A). Analysis of selected HbS polymorphism showed significant association with protective effect against severe malaria with a significant p-value = 0.033 (OR 0.38, 95% CI [0.16-0.91]) for SM vs. UM comparison. Surprisingly, our study did not identify the protective effect of variant HbC polymorphism against severe malaria. Finally, we found some of the polymorphisms, like HbS (rs334), are associated with age and biological parameters like eosinophils, basophils, lymphocytes etc. Conclusion Our data report HBB and G6PD polymorphisms in the Senegalese population and their correlation with severe/mild malaria and outcome. The G6PD and HBB deficiencies are widespread in West Africa endemic malaria regions such as The Gambia, Mali, and Burkina Faso. The study shows the critical role of genetic factors in malaria outcomes. Indeed, genetic markers could be good tools for malaria endemicity prognosis.
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Affiliation(s)
- Fatou Thiam
- Groupe de Recherche Biotechnologie Appliquée et Bioprocédés Environnementaux (GRBA-BE), Laboratoire Eau, Energie, Environnement et Procédés Industriels (LE3PI), Département de Génie Chimique et Biologie Appliquée, Ecole Supérieure Polytechnique, Université Cheikh Anta DIOP de Dakar, Dakar Fann, Dakar, Sénégal
| | - Gora Diop
- Unité Postulante de Biologie Génétique, Génomique et Bio-informatique (G2B), Département de Biologie Animale, Faculté des Sciences et Techniques, Université Cheikh Anta DIOP, Avenue Cheikh Anta DIOP, Dakar Fann, Dakar, Sénégal,Pole d’Immunophysiopathologie & Maladies Infectieuses (IMI), Institut Pasteur de Dakar, Dakar, Sénégal
| | - Cedric Coulonges
- Equipe GBA «Génomique, Bioinformatique & Applications », Conservatoire National des Arts et Métiers, Paris, France
| | - Céline Derbois
- CEA, Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, Evry, France
| | - Babacar Mbengue
- Service d’Immunologie, Faculté de Médecine, de Pharmacie et d’Odontostomatologie, Université Cheikh Anta DIOP, Dakar, Sénégal
| | - Alassane Thiam
- Pole d’Immunophysiopathologie & Maladies Infectieuses (IMI), Institut Pasteur de Dakar, Dakar, Sénégal
| | - Cheikh Momar Nguer
- Groupe de Recherche Biotechnologie Appliquée et Bioprocédés Environnementaux (GRBA-BE), Laboratoire Eau, Energie, Environnement et Procédés Industriels (LE3PI), Département de Génie Chimique et Biologie Appliquée, Ecole Supérieure Polytechnique, Université Cheikh Anta DIOP de Dakar, Dakar Fann, Dakar, Sénégal
| | - Jean Francois Zagury
- Equipe GBA «Génomique, Bioinformatique & Applications », Conservatoire National des Arts et Métiers, Paris, France
| | - Jean-Francois Deleuze
- CEA, Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, Evry, France
| | - Alioune Dieye
- Service d’Immunologie, Faculté de Médecine, de Pharmacie et d’Odontostomatologie, Université Cheikh Anta DIOP, Dakar, Sénégal
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