Figure 5.
Characterization of cellular immune response induced by DENV DNA vaccine in mice
(A) Schedule of vaccination and T cell assays. BALB/c (n = 6/group) and C57BL/6J (n = 5/group) were immunized with 50 μg DENV DNA vaccine or pVAX1 control and sacrificed at 2 weeks after the 2nd booster, and spleens were analyzed for T cell responses by ELISpot and flow cytometry. (B) Map of the DDV and predicted potential immunodominant peptides through NETCTL and VAXIJEN. (C–F) Antigen-specific T responses to pooled EDIII-NS1 and HIV-Nef peptides were measured by IFN-γ ELISpot after vaccination with DDV or pVAX1 in BALB/c (C and D) and C57BL/6J animals (E and F) (pool 1: EDIII peptide mixture; pool 2: NS1 peptide mixture; pool 3; EDIII and NS1 peptide mixture; pool 4: HIV-Nef peptide mixture). (G–J) Flow cytometric analysis of intracellular cytokine staining for IFN-γ in C57BL/6J mice (n = 5/group) splenocytes. (G and H) Representative image of intracellular IFN-γ staining in CD8+ and CD4+ T cells in DDV-vaccinated mice splenocytes, respectively. (I and J) Percentage of IFNγ+ CD8+ and IFNγ+ CD4+ T cells in DDV- and pVAX1-control-vaccinated animals determined through the intracellular cytokine staining (ICC; pool 1: ConA; pool 2: DENV EDIII and NS1 peptides). Data are representative of three independent experiments. Values are depicted are mean ± SD. The percentage of IFN-γ-producing T cells was compared between groups with Student’s unpaired t test; ∗p ≤ 0.05, ∗∗p ≤ 0.005, ∗∗∗p ≤ 0.0005. The study design schematic diagram was created with BioRender.com.