Further evaluation of the NWF filter for the purification of Plasmodium vivax-infected erythrocytes

Li, Jiangyan; Tao, Zhi‐Yong; Li, Qian; Brashear, Awtum; Wang, Ying; Xing, Hui; Fang, Qiang

doi:10.1186/s12936-017-1855-3

Cited by 14 publications

(13 citation statements)

References 21 publications

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“…Venous blood used for in vitro invasion assays was collected in lithium heparin tubes and immediately processed on-site in a mobile laboratory. Leukocytes were depleted using NWF filters 36 . The leukocytedepleted parasitized red blood cells were cryopreserved using glycerolyte 57 solution (Baxter) and immediately stored in liquid nitrogen 37 .…”

Section: Methodsmentioning

confidence: 99%

Amplification of Duffy binding protein-encoding gene allows Plasmodium vivax to evade host anti-DBP humoral immunity

et al. 2020

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Antigenic variation, the capacity to produce a range of variable antigens, is a well-described strategy of Plasmodium and other parasites to evade host immunity. Here, we show that gene amplification is an additional evasion mechanism used by Plasmodium vivax to escape humoral immunity targeting PvDBP, the key ligand involved in reticulocyte invasion. PvDBP gene amplification leads to increased mRNA levels and protects P. vivax in vitro against invasion inhibitory human monoclonal antibodies targeting a conserved binding domain of DBP. Patient samples suggest that parasites with increased pvdbp copy number are able to infect individuals with naturally acquired antibodies highly blocking the binding of PvDBP to the Duffy receptor. These results show that gene copy number variation affect the parasite's ability to evade anti-PvDBP humoral immunity.

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Section: Methodsmentioning

confidence: 99%

Amplification of Duffy binding protein-encoding gene allows Plasmodium vivax to evade host anti-DBP humoral immunity

et al. 2020

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“…Malaria diagnosis was performed by microscopic examination of Giemsa-stained blood smears. Five milliliters of venous blood were drawn by venipuncture from each patient and filtered to remove human leukocytes as previously described [ 21 ]. Parasites were released after lysis of the red blood cells (RBCs) with saponin, pelleted by centrifugation, and stored at -80°C until DNA extraction.…”

Section: Methodsmentioning

confidence: 99%

Population genomics identifies a distinct Plasmodium vivax population on the China-Myanmar border of Southeast Asia

Brashear

Fan

et al. 2020

PLoS Negl Trop Dis

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Plasmodium vivax has become the predominant malaria parasite and a major challenge for malaria elimination in the Greater Mekong Subregion (GMS). Yet, our knowledge about the evolution of P. vivax populations in the GMS is fragmental. We performed whole genome sequencing on 23 P. vivax samples from the China-Myanmar border (CMB) and used 21 high-coverage samples to compare to over 200 samples from the rest of the GMS. Using genome-wide single nucleotide polymorphisms (SNPs), we analyzed population differentiation, genetic structure, migration and potential selection using an array of methods. The CMB parasites displayed a higher proportion of monoclonal infections, and 52% shared over 90% of their genomes in identity-by-descent segments with at least one other sample from the CMB, suggesting preferential expansion of certain parasite strains in this region, likely resulting from the P. vivax outbreaks occurring during this study period. Principal component, admixture, fixation index and phylogenetic analyses all identified that parasites from the CMB were genetically distinct from parasites from eastern parts of the GMS (Cambodia, Laos, Vietnam, and Thailand), whereas the eastern GMS parasite populations were largely undifferentiated. Such a genetic differentiation pattern of the P. vivax populations from the GMS parasite was largely explainable through geographic distance. Using the genomewide SNPs, we narrowed down to a set of 36 SNPs for differentiating parasites from different areas of the GMS. Genome-wide scans to determine selection in the genome with two statistical methods identified genes potentially under drug selection, including genes associated with antifolate resistance and genes linked to chloroquine resistance in Plasmodium falciparum.

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“…The schizont maturation assay was used to assess ex vivo susceptibility of P. vivax field isolates to antimalarial drugs [52]. For each isolate, 2 mL of P. vivax-infected blood were centrifuged at 1,000 rpm for 10 min, and the pellet was re-suspended in two volumes of serum-free RPMI 1640 medium.…”

Section: In Vitro Drug Assaymentioning

confidence: 99%

Ex vivo susceptibilities of Plasmodium vivax isolates from the China-Myanmar border to antimalarial drugs and association with polymorphisms in Pvmdr1 and Pvcrt-o genes

Zhang

et al. 2020

PLoS Negl Trop Dis

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Background Vivax malaria is an important public health problem in the Greater Mekong Subregion (GMS), including the China-Myanmar border. Previous studies have found that Plasmodium vivax has decreased sensitivity to antimalarial drugs in some areas of the GMS, but the sensitivity of P. vivax to antimalarial drugs is unclear in the China-Myanmar border. Here, we investigate the drug sensitivity profile and genetic variations for two drug resistance related genes in P. vivax isolates to provide baseline information for future drug studies in the China-Myanmar border. Methodology/Principal findings A total of 64 P. vivax clinical isolates collected from the China-Myanmar border area were assessed for ex vivo susceptibility to eight antimalarial drugs by the schizont maturation assay. The medians of IC 50 (half-maximum inhibitory concentrations) for chloroquine, mefloquine, pyronaridine, piperaquine, quinine, artesunate, artemether, dihydroartemisinin were 84.2 nM, 34.9 nM, 4.0 nM, 22.3 nM, 41.4 nM, 2.8 nM, 2.1 nM and 2.0 nM, respectively. Twelve P. vivax clinical isolates were found over the cutoff IC 50 value (220 nM) for chloroquine resistance. In addition, sequence polymorphisms in pvmdr1 (P. vivax multidrug resistance-1), pvcrt-o (P. vivax chloroquine resistance transporter-o), and difference in pvmdr1 copy number were studied. Sequencing of the pvmdr1 gene in 52 samples identified 12 amino acid substitutions, among which two (G698S and T958M) were fixed, M908L were present in 98.1% of the isolates, while Y976F and F1076L were present in 3.8% and 78.8% of the isolates, respectively. Amplification of the pvmdr1 gene was only detected in 4.8% of PLOS NEGLECTED TROPICAL DISEASES

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Further evaluation of the NWF filter for the purification of Plasmodium vivax-infected erythrocytes

Cited by 14 publications

References 21 publications

Amplification of Duffy binding protein-encoding gene allows Plasmodium vivax to evade host anti-DBP humoral immunity

Amplification of Duffy binding protein-encoding gene allows Plasmodium vivax to evade host anti-DBP humoral immunity

Population genomics identifies a distinct Plasmodium vivax population on the China-Myanmar border of Southeast Asia

Ex vivo susceptibilities of Plasmodium vivax isolates from the China-Myanmar border to antimalarial drugs and association with polymorphisms in Pvmdr1 and Pvcrt-o genes

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