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Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate--Tackling the Cocktail Challenge.

Boes A, Spiegel H, Voepel N, Edgue G, Beiss V, Kapelski S, Fendel R, Scheuermayer M, Pradel G, Bolscher JM, Behet MC, Dechering KJ, Hermsen CC, Sauerwein RW, Schillberg S, Reimann A, Fischer R - PLoS ONE (2015)

Bottom Line: To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants.Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%).While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

View Article: PubMed Central - PubMed

Affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany.

ABSTRACT
Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%). Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17-25 μg/ml), the blood stage (40-60 μg/ml) and the sexual stage (1.75 μg/ml). While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

No MeSH data available.


Related in: MedlinePlus

In vitro inhibition of (A) sporozoite gliding motility, (B) hepatocyte cell traversal, (C) sporozoite invasion and liver stage development with PlasmoMix-specific rabbit IgG and (D) Dose response of sporozoite invasion and liver stage development.All three assays were performed with P. falciparum NF54 parasites and purified rabbit IgGs (R1, R2 and R3) at a total IgG concentration of 3 mg/ml from serum samples collected on days 63 and 91. For the dose response, purified rabbit IgGs from rabbit R3 (day 63 and day 91) was used at the following total IgG concentrations: 9, 3, 0.9 and 0.09 mg/ml. The CCT-specific antibody concentration was calculated based on CFCA from total IgG. Inhibitions are expressed as the mean of duplicate measurements with standard deviations.
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pone.0131456.g003: In vitro inhibition of (A) sporozoite gliding motility, (B) hepatocyte cell traversal, (C) sporozoite invasion and liver stage development with PlasmoMix-specific rabbit IgG and (D) Dose response of sporozoite invasion and liver stage development.All three assays were performed with P. falciparum NF54 parasites and purified rabbit IgGs (R1, R2 and R3) at a total IgG concentration of 3 mg/ml from serum samples collected on days 63 and 91. For the dose response, purified rabbit IgGs from rabbit R3 (day 63 and day 91) was used at the following total IgG concentrations: 9, 3, 0.9 and 0.09 mg/ml. The CCT-specific antibody concentration was calculated based on CFCA from total IgG. Inhibitions are expressed as the mean of duplicate measurements with standard deviations.

Mentions: The inhibitory efficacy of the pre-erythrocytic stage components in the context of the fusion protein CCT was investigated using PlasmoMix-specific rabbit immune IgG in SGM, HCT and SILSD assays. IgG samples from all three rabbits were tested in duplicate at a final concentration of 3 mg/ml and we observed up to 48% inhibition of SGM, 34% inhibition of HCT and 81% inhibition of SILSD (Fig 3). Further, IC50 values for the inhibition of SILSD were determined in a dose response experiment using purified immune IgG from rabbit R3 at day 63 and 91 (R3_63: 25.5 μg/ml and R3_91: 17.1 μg/ml).


Analysis of a Multi-component Multi-stage Malaria Vaccine Candidate--Tackling the Cocktail Challenge.

Boes A, Spiegel H, Voepel N, Edgue G, Beiss V, Kapelski S, Fendel R, Scheuermayer M, Pradel G, Bolscher JM, Behet MC, Dechering KJ, Hermsen CC, Sauerwein RW, Schillberg S, Reimann A, Fischer R - PLoS ONE (2015)

In vitro inhibition of (A) sporozoite gliding motility, (B) hepatocyte cell traversal, (C) sporozoite invasion and liver stage development with PlasmoMix-specific rabbit IgG and (D) Dose response of sporozoite invasion and liver stage development.All three assays were performed with P. falciparum NF54 parasites and purified rabbit IgGs (R1, R2 and R3) at a total IgG concentration of 3 mg/ml from serum samples collected on days 63 and 91. For the dose response, purified rabbit IgGs from rabbit R3 (day 63 and day 91) was used at the following total IgG concentrations: 9, 3, 0.9 and 0.09 mg/ml. The CCT-specific antibody concentration was calculated based on CFCA from total IgG. Inhibitions are expressed as the mean of duplicate measurements with standard deviations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492585&req=5

pone.0131456.g003: In vitro inhibition of (A) sporozoite gliding motility, (B) hepatocyte cell traversal, (C) sporozoite invasion and liver stage development with PlasmoMix-specific rabbit IgG and (D) Dose response of sporozoite invasion and liver stage development.All three assays were performed with P. falciparum NF54 parasites and purified rabbit IgGs (R1, R2 and R3) at a total IgG concentration of 3 mg/ml from serum samples collected on days 63 and 91. For the dose response, purified rabbit IgGs from rabbit R3 (day 63 and day 91) was used at the following total IgG concentrations: 9, 3, 0.9 and 0.09 mg/ml. The CCT-specific antibody concentration was calculated based on CFCA from total IgG. Inhibitions are expressed as the mean of duplicate measurements with standard deviations.
Mentions: The inhibitory efficacy of the pre-erythrocytic stage components in the context of the fusion protein CCT was investigated using PlasmoMix-specific rabbit immune IgG in SGM, HCT and SILSD assays. IgG samples from all three rabbits were tested in duplicate at a final concentration of 3 mg/ml and we observed up to 48% inhibition of SGM, 34% inhibition of HCT and 81% inhibition of SILSD (Fig 3). Further, IC50 values for the inhibition of SILSD were determined in a dose response experiment using purified immune IgG from rabbit R3 at day 63 and 91 (R3_63: 25.5 μg/ml and R3_91: 17.1 μg/ml).

Bottom Line: To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants.Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%).While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

View Article: PubMed Central - PubMed

Affiliation: Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Aachen, Germany.

ABSTRACT
Combining key antigens from the different stages of the P. falciparum life cycle in the context of a multi-stage-specific cocktail offers a promising approach towards the development of a malaria vaccine ideally capable of preventing initial infection, the clinical manifestation as well as the transmission of the disease. To investigate the potential of such an approach we combined proteins and domains (11 in total) from the pre-erythrocytic, blood and sexual stages of P. falciparum into a cocktail of four different components recombinantly produced in plants. After immunization of rabbits we determined the domain-specific antibody titers as well as component-specific antibody concentrations and correlated them with stage specific in vitro efficacy. Using purified rabbit immune IgG we observed strong inhibition in functional in vitro assays addressing the pre-erythrocytic (up to 80%), blood (up to 90%) and sexual parasite stages (100%). Based on the component-specific antibody concentrations we calculated the IC50 values for the pre-erythrocytic stage (17-25 μg/ml), the blood stage (40-60 μg/ml) and the sexual stage (1.75 μg/ml). While the results underline the feasibility of a multi-stage vaccine cocktail, the analysis of component-specific efficacy indicates significant differences in IC50 requirements for stage-specific antibody concentrations providing valuable insights into this complex scenario and will thereby improve future approaches towards malaria vaccine cocktail development regarding the selection of suitable antigens and the ratios of components, to fine tune overall and stage-specific efficacy.

No MeSH data available.


Related in: MedlinePlus