Combination of E- and NS1-Derived DNA Vaccines: The Immune Response and Protection Elicited in Mice against DENV2

• Published in: Viruses Vol. 14; no. 7; p. 1452
• Main Authors: Pinto, Paolla Beatriz A, Barros, Tamiris A. C, Lima, Lauro M, Pacheco, Agatha R, Assis, Maysa L, Pereira, Bernardo A. S, Gonçalves, Antônio J. S, Azevedo, Adriana S, Neves-Ferreira, Ana Gisele C, Costa, Simone M, Alves, Ada M. B
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30.06.2022; MDPI
• Subjects: Antibodies; Antigens; Cloning; Cytomegalovirus; Dengue fever; dengue vaccine; Deoxyribonucleic acid; Disease; DNA; DNA vaccine; DNA vaccines; E protein; Enzyme-linked immunosorbent assay; Genomes; Glycoproteins; Immune response; Immunization; Immunofluorescence; Immunological research; Infections; Mass spectroscopy; NS1 protein; Peptides; Plasmids; Proteins; Recombinant proteins; Splenocytes; Synthetic peptides; Testing; Vaccines; Viral infections; γ-Interferon; Brazil; United States > US
• ISSN: 1999-4915; 1999-4915
• DOI: 10.3390/v14071452

The occurrence of dengue disease has increased radically in recent decades. Previously, we constructed the pE1D2 and pcTPANS1 DNA vaccines encoding the DENV2 envelope (E) and non-structural 1 (NS1) proteins, respectively. To decrease the number of plasmids in a tetravalent candidate vaccine, we constructed a bicistronic plasmid, pNS1/E/D2, encoding these two proteins simultaneously. We evaluated the protective immunity induced in mice vaccinated with the pNS1/E/D2 candidate and compared to the responses elicited by immunization with the former vaccines isolated or in combination. We transfected BHK-21 cells with the different plasmids and detected recombinant proteins by immunofluorescence and mass spectrometry assays to confirm antigen expression. BALB/c mice were inoculated with the DNA vaccines followed by a lethal DENV2 challenge. ELISA, PRNT50, and IFN-gamma ELISPOT assays were performed for the investigation of the humoral and cellular responses. We observed the concomitant expression of NS1 and E proteins in pNS1/E/D2-transfected cells. All E-based vaccines induced anti-E and neutralizing antibodies. However, anti-NS1 antibodies were only observed after immunization with the pcTPANS1 administered alone or combined with pE1D2. In contrast, splenocytes from pNS1/E/D2- or pcTPANS1 + pE1D2-vaccinated animals responded to NS1- and E-derived synthetic peptides. All the DNA vaccines conferred protection against DENV2.