Figure 4. Disease outcome upon challenge with D2Y98P-PP1 of pups born to PDK53-immunized dams and vaccinated with PDK53 or passively transferred with CD4⁺ or CD8⁺ T cells.

Three-wko A129 pups born to PDK53-immunized or naive dams were vaccinated, or not, with PDK53 and challenged at 6 weeks of age with 10⁷ PFU of D2Y98P-PP1 strain. (A and B) Clinical scores. Euthanasia was performed at a clinical score of 4. Medians and interquartile ranges of 5–6 mice per group are shown. (C) D2Y98P-PP1 viremia and organ viral loads. Nominal values were assigned to viral loads below limit of detection. Mann-Whitney test was performed to compare viral loads between the nonvaccinated groups. (D and E) Five- to 7-wko mice born to PDK53-immune or DENV-naive dams were transferred with 1.5 × 10⁷ naive or PDK53-primed CD4⁺ (D) or CD8⁺ (E) T cells and challenged with 10⁷ PFU of D2Y98P-PP1 one day later. Medians and interquartile ranges of 7–8 (D) and 5 (E) mice per group are shown. Euthanasia was performed at a clinical score of 4. Data are representative of 2 independent experiments. (F) Clinical scores of 6-wko A129 mice (n = 8) born to PDK53-immunized dams, and adoptively transferred with 6 × 10⁶ CD8⁺ T cells 1 day prior to D2Y98P-PP1 challenge (10⁶ PFU). The CD8⁺ T cells transferred were either nonspecifically activated or PDK53-primed. (G) D2Y98P-PP1 viremia at day 4 after challenge (n = 4) in mice transferred with either nonspecifically activated CD8⁺ T cells or PDK53-primed CD8⁺ T cells. Kruskal-Wallis test with Dunn’s multiple comparison was performed. *P ≤ 0.05; ns, P > 0.05. Data are representative of 2 independent experiments.