Immunogenicity and neutralizing activity induced by virus-like particles based on Junín and dengue viruses conserved sequences

MAREZE, V.A.; BORIO, C.S.; MIRAZO VILLAR, S.; HUPNER, C.; PINHEIRO GONZALES, R.; BILEN, M.F.; SANTOS MANSUR, D.; ARBIZA, J.; LOZANO, M.E.; BRUÑA ROMERO, O.

Buzios

Congreso; XXXIX Congress of the Brazilian Society of Immunology; 2014

Brazilian Society of Immunology

Introduction Dengue is a mosquito-borne viral disease prevalent in more than a hundred countries. Currently, five serotypes of Dengue virus (DENV) have been identified but no effective vaccine is yet available. Recently, Junín virus-like-particles (JUNV-VLPs) have been generated, resulting in 3D structures that mimic authentic viral particles and are suitable carriers of heterologous sequences to induce host´s immune responses. Here, two highly conserved DENV peptides (P1 and P2) were used as antigens individually or within VLPs as part of a prime-boost immunization protocol. Methods and Results A plasmid encoding chimeric JUNV-DENV VLPs was generated and purified by ultracentrifugation in a cesium chloride gradient. When transfected into HEK 293 cells, VLP structures were visualized by TEM (Transmission Electronic Microscopy) and fluorescence microscopy. C57BL/6 mice (8 weeks) were immunized with a priming DNA dose, followed by a booster dose of synthetic peptides P1 and P2 in adjuvant. ELISA tests demonstrated the induction of an anti-DENV specific humoral response after boost, and DENV Plaque Reduction Neutralization Tests (PRNT) showed that no significant inhibition of infection could be achieved when using anti-P1 antibodies, but around 50% reduction was obtained when using P2 as antigen. Conclusion A peptide was identified within DENV that may serve as a new pentavalent vaccine candidate, deserving further testing in rodent and primate virus-challenge models.