title: Protection against dengue type 2 virus induced in mice immunized with a DNA plasmid encoding the non-structural 1 (NS1) gene fused to the tissue plasminogen activator signal sequence.
abstract: Dengue is one of the most important arboviral diseases in humans, and although efforts over the last decades have dealt with the development of a vaccine, this vaccine is not available yet. In order to evaluate the potential of a DNA vaccine based on the non-structural 1 (NS1) protein against dengue virus (DENV), we constructed the pcTPANS1 plasmid which contains the secretory signal sequence derived from human tissue plasminogen activator (t-PA) fused to the full length of the DENV-2 NS1 gene. Results indicate that pcTPANS1 promotes correct expression of NS1 in eukaryotic cells and drives secretion of the recombinant protein to the surrounding medium in a dimeric form. Balb/c mice, intramuscularly inoculated with this plasmid, presented high levels of antibodies, recognizing mainly surface-exposed conformational epitopes present in the NS1 protein expressed by insect cells. Long-term antibody response was observed in animals 56 weeks after the first plasmid inoculation, and a rapid, efficient secondary response was observed after a DNA boost. Vaccinated animals were challenged against DENV-2 in two murine models, based on intracerebral (i.c.) and intraperitoneal (i.p.) virus inoculations, and in both cases, pcTPANS1-immunized mice were protected. Overall, these results provide further support for the use of such a plasmid in a possible approach for the development of a vaccine against DENV.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Av. Brazil 4365, Pav. Leonidas Deane, sala 204, Rio de Janeiro, RJ, CEP 21040-900, Brazil.
authors.forename: Simone M
authors.initials: SM
authors.lastname: Costa
authors.forename: Marciano V
authors.initials: MV
authors.lastname: Paes
authors.forename: Débora F
authors.initials: DF
authors.lastname: Barreto
authors.forename: Angela T
authors.initials: AT
authors.lastname: Pinhão
authors.forename: Ortrud M
authors.initials: OM
authors.lastname: Barth
authors.forename: João L S
authors.initials: JL
authors.lastname: Queiroz
authors.forename: Geraldo R G
authors.initials: GR
authors.lastname: Armôa
authors.forename: Marcos S
authors.initials: MS
authors.lastname: Freire
authors.forename: Ada M B
authors.initials: AM
authors.lastname: Alves
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D001483:Base Sequence; D017931:DNA Primers; D003716:Dengue Virus / Q000276:immunology*; D050939:Gene Fusion; D051379:Mice; D010957:Plasmids; D010959:Tissue Plasminogen Activator / Q000235:genetics*; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000235:genetics*; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D017931:DNA Primers; C079340:NS1 protein, Dengue virus type 2; D019444:Vaccines, DNA; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines; D010959:Tissue Plasminogen Activator