Effective and cheap removal of leukocytes and platelets from Plasmodium vivax infected blood

Sriprawat, Kanlaya; Kaewpongsri, Supaporn; Suwanarusk, Rossarin; Leimanis, Mara L.; Lek-Uthai, Usa; Phyo, Aung Pyae; Snounou, Georges; Russell, Bruce; Rénia, Laurent; Nosten, François

doi:10.1186/1475-2875-8-115

Cited by 96 publications

(102 citation statements)

References 17 publications

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“…These blood samples were collected by venipuncture in 5-ml-volume lithium heparinized tubes, which were transported to the laboratory at SMRU within 5 h of collection. White blood cells and platelets were removed using a CF11 column (35). The P. vivaxinfected erythrocytes were cultured to the late schizont stage in 2% hematocrit (Hct) McCoy's 5A medium supplemented with 2.4 g/liter D-glucose, 40 mg/ml gentamicin sulfate, and 20% heat-inactivated human AB serum, in an atmosphere of 5% O 2 at 37.5°C for ϳ44 h. The mature schizonts were concentrated on a cushion of 45% Percoll (isotonic) centrifuged for 15 min at 1,600 ϫ g (36).…”

Section: Methodsmentioning

confidence: 99%

Invasion-Inhibitory Antibodies Elicited by Immunization with Plasmodium vivax Apical Membrane Antigen-1 Expressed in Pichia pastoris Yeast

et al. 2014

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h In a recent vaccine trial performed with African children, immunization with a recombinant protein based on Plasmodium falciparum apical membrane antigen 1 (AMA-1) conferred a significant degree of strain-specific resistance against malaria. To contribute to the efforts of generating a vaccine against Plasmodium vivax malaria, we expressed the ectodomain of P. vivax AMA-1 (PvAMA-1) as a secreted soluble protein in the methylotrophic yeast Pichia pastoris. Recognized by a high percentage of sera from individuals infected by P. vivax, this recombinant protein was found to have maintained its antigenicity. The immunogenicity of this protein was evaluated in mice using immunization protocols that included homologous and heterologous primeboost strategies with plasmid DNA and recombinant protein. We used the following formulations containing different adjuvants: aluminum salts (Alum), Bordetella pertussis monophosphoryl lipid A (MPLA), flagellin FliC from Salmonella enterica serovar Typhimurium, saponin Quil A, or incomplete Freund's adjuvant (IFA). The formulations containing the adjuvants Quil A or IFA elicited the highest IgG antibody titers. Significant antibody titers were also obtained using a formulation developed for human use containing MPLA or Alum plus MPLA. Recombinant PvAMA-1 produced under "conditions of good laboratory practice" provided a good yield, high purity, low endotoxin levels, and no microbial contaminants and reproduced the experimental immunizations. Most relevant for vaccine development was the fact that immunization with PvAMA-1 elicited invasioninhibitory antibodies against different Asian isolates of P. vivax. Our results show that AMA-1 expressed in P. pastoris is a promising antigen for use in future preclinical and clinical studies.

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Section: Methodsmentioning

confidence: 99%

Invasion-Inhibitory Antibodies Elicited by Immunization with Plasmodium vivax Apical Membrane Antigen-1 Expressed in Pichia pastoris Yeast

et al. 2014

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“…To obtain high levels of reticulocytes to be used as target cells in the invasion assay, reticulocytemia was induced in groups of four to six naive mice by repeated daily retro-orbital bleeding for 6 days. Leukocyte removal from the reticulocyte-enriched blood was achieved after two cycles of CF11 filtration (33).…”

Section: Methodsmentioning

confidence: 99%

Immunization with the MAEBL M2 Domain Protects against Lethal Plasmodium yoelii Infection

et al. 2015

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“…With written informed consent, 5 ml of venous blood was collected by venipuncture and processed immediately. Host white blood cells were removed using cellulose columns as previously described (13), and packed infected red blood cells (iRBC) were used for the ex vivo drug susceptibility assay.…”

Section: Methodsmentioning

confidence: 99%

Contrasting Ex Vivo Efficacies of “Reversed Chloroquine” Compounds in Chloroquine-Resistant Plasmodium falciparum and P. vivax Isolates

Wirjanata

Sebayang

Chalfein

et al. 2015

Antimicrob Agents Chemother

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h Chloroquine (CQ) has been the mainstay of malaria treatment for more than 60 years. However, the emergence and spread of CQ resistance now restrict its use to only a few areas where malaria is endemic. The aim of the present study was to investigate whether a novel combination of a CQ-like moiety and an imipramine-like pharmacophore can reverse CQ resistance ex vivo. Between March to October 2011 and January to September 2013, two "reversed chloroquine" (RCQ) compounds (PL69 and PL106) were tested against multidrug-resistant field isolates of Plasmodium falciparum (n ‫؍‬ 41) and Plasmodium vivax (n ‫؍‬ 45) in Papua, Indonesia, using a modified ex vivo schizont maturation assay. The RCQ compounds showed high efficacy against both CQ-resistant P. falciparum and P. vivax field isolates. For P. falciparum, the median 50% inhibitory concentrations (IC 50 s) were 23.2 nM for PL69 and 26.6 nM for PL106, compared to 79.4 nM for unmodified CQ (P < 0.001 and P ‫؍‬ 0.036, respectively). The corresponding values for P. vivax were 19.0, 60.0, and 60.9 nM (P < 0.001 and P ‫؍‬ 0.018, respectively). There was a significant correlation between IC 50 s of CQ and PL69 (Spearman's rank correlation coefficient [r s ] ‫؍‬ 0.727, P < 0.001) and PL106 (r s ‫؍‬ 0.830, P < 0.001) in P. vivax but not in P. falciparum. Both RCQs were equally active against the ring and trophozoite stages of P. falciparum, but in P. vivax, PL69 and PL106 showed less potent activity against trophozoite stages (median IC 50 s, 130.2 and 172.5 nM) compared to ring stages (median IC 50 s, 17.6 and 91.3 nM). RCQ compounds have enhanced ex vivo activity against CQ-resistant clinical isolates of P. falciparum and P. vivax, suggesting the potential use of reversal agents in antimalarial drug development. Interspecies differences in RCQ compound activity may indicate differences in CQ pharmacokinetics between the two Plasmodium species.

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Effective and cheap removal of leukocytes and platelets from Plasmodium vivax infected blood

Cited by 96 publications

References 17 publications

Invasion-Inhibitory Antibodies Elicited by Immunization with Plasmodium vivax Apical Membrane Antigen-1 Expressed in Pichia pastoris Yeast

Invasion-Inhibitory Antibodies Elicited by Immunization with Plasmodium vivax Apical Membrane Antigen-1 Expressed in Pichia pastoris Yeast

Immunization with the MAEBL M2 Domain Protects against Lethal Plasmodium yoelii Infection

Contrasting Ex Vivo Efficacies of “Reversed Chloroquine” Compounds in Chloroquine-Resistant Plasmodium falciparum and P. vivax Isolates

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