Luciano Zane, Brazil

Instituto Butantan Laboratorio de Desenvolvimento de Vacinas

Poster Author Of 1 e-Poster

Online Abstracts Vaccines - Pneumococcal Vaccines Development C1 Pneumococcal Vaccines Development

Presenter of 1 Presentation

EVALUATING THE ANTIGENICITY AND STABILITY OF A HYBRID MOLECULE OF PNEUMOCOCCAL SURFACE PROTEIN A (PSPA) AND GENETICALLY DETOXIFIED PNEUMOLYSIN (PDT) USING MOLECULAR LINKERS (ID 417)

Session Name
Vaccines - Pneumococcal Vaccines Development

Abstract

Background

Pneumococcal protein vaccines have been proposed as better serotype-independent alternatives to already used polysaccharide-based vaccines in order to increase coverage. PspA and PdT were genetically fused and protected mice against lethal challenge, offered higher cross protection against different strains and showed greater opsonophagocytosis rate than co-administered proteins. As juxtaposed fusion was unstable, flexible (PspA-FL-PdT) and rigid (PspA-RL-PdT) linkers were inserted between antigens to increase stability. This work aimed to produce stable hybrid molecules and evaluate their antigenicity.

Methods

The two constructs were cloned into E. coli and clones were cultivated in defined culture media. Hybrids were purified from soluble fraction using chromatography and stability was evaluated by Western blot. Mice were immunized, antibody production was evaluated by ELISA, and aspiration lethal challenge was performed.

Results

High purity was obtained for both molecules (>95%). Hybrids were stable for at least 12 months at -20°C, and PspA-FL-PdT was stable at 4°C for this period. Although both hybrids elicited high antibody levels, only PspA-RL-PdT protected mice against lethal challenge. New immunization assay is being conducted to evaluate protein dose for immunization and bacterial concentration at challenge.

Conclusions

Promising protection and stability were achieved, but further investigation is still needed to formulate a new protein based vaccine.

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Author Of 1 Presentation

EVALUATING THE ANTIGENICITY AND STABILITY OF A HYBRID MOLECULE OF PNEUMOCOCCAL SURFACE PROTEIN A (PSPA) AND GENETICALLY DETOXIFIED PNEUMOLYSIN (PDT) USING MOLECULAR LINKERS (ID 417)

Session Name
Vaccines - Pneumococcal Vaccines Development

Abstract

Background

Pneumococcal protein vaccines have been proposed as better serotype-independent alternatives to already used polysaccharide-based vaccines in order to increase coverage. PspA and PdT were genetically fused and protected mice against lethal challenge, offered higher cross protection against different strains and showed greater opsonophagocytosis rate than co-administered proteins. As juxtaposed fusion was unstable, flexible (PspA-FL-PdT) and rigid (PspA-RL-PdT) linkers were inserted between antigens to increase stability. This work aimed to produce stable hybrid molecules and evaluate their antigenicity.

Methods

The two constructs were cloned into E. coli and clones were cultivated in defined culture media. Hybrids were purified from soluble fraction using chromatography and stability was evaluated by Western blot. Mice were immunized, antibody production was evaluated by ELISA, and aspiration lethal challenge was performed.

Results

High purity was obtained for both molecules (>95%). Hybrids were stable for at least 12 months at -20°C, and PspA-FL-PdT was stable at 4°C for this period. Although both hybrids elicited high antibody levels, only PspA-RL-PdT protected mice against lethal challenge. New immunization assay is being conducted to evaluate protein dose for immunization and bacterial concentration at challenge.

Conclusions

Promising protection and stability were achieved, but further investigation is still needed to formulate a new protein based vaccine.

Hide