Skip to main content
. 2012 Nov 8;3:334. doi: 10.3389/fimmu.2012.00334

FIGURE 3.

FIGURE 3

DENV-1 CRR vaccine stimulates reduced levels of immunodominant cross-reactive EDIIFP IgG and reduces enhanced DENV-2 mortality. (A–C) 12 week post vaccination immunogenicity of AG129 mice immunized (i.m.) with 100 μg of pVD1-WT or pVD1-CRR vaccines. Geometric means and 95% confidence intervals are depicted. Endpoint titers were log10 transformed and statistical significance was determined using the two-tailed Mann–Whitney U test. Panels B and C both used a one-tailed test since there was an a priori expectation that pVD1-CRR immunized mice would exhibit reduced EDIIFP recognizing IgG. (A) DENV-1 total IgG endpoint titers 12 weeks post immunization. (B) Percent of total DENV-1 IgG recognizing immunodominant EDIIFP epitopes, arithmetic means and 95% CI depicted. (C) Calculated DENV-1 EDIIFP IgG endpoint titers. (D) Survival of pVD1-WT and pVD1-CRR immunized AG129 mice following sub-lethal heterologous DENV-2 challenge. 12 weeks following vaccination, immunized mice (n = 22) or age matched naїve controls (n = 8) were challenged (i.p.) with 4.2 × 105 FFU of DENV-2 S221. Kaplan-Meier survival curves and p values are shown. All naїve mice survived virus challenge with minimal signs of morbidity, pVD1-WT vaccinated mice suffered 95% mortality from enhanced DENV-2 disease (p < 0.0001, compared to naive). pVD1-CRR immunized mice exhibited 68% survival which did not differ from naїve mouse survival (100%, p = 0.0769) yet was significantly greater than pVD1-WT immunized mouse survival (4.5%, p < 0.0001). The Bonferroni multiple comparison adjusted α = 0.017. (E) pVD1-CRR vaccinated mice exhibited a rapid, large magnitude increase in DENV-2 neutralizing antibody titers following DENV-2 challenge. FRμNT50 titers determined with DENV-2 16681 virus on Vero cells, log10 transformed and the transformed data analyzed by two-way ANOVA (p < 0.0001). Bonferroni post hoc test significance is depicted with asterisks, error bars represent SEM. 0, 3, 4, and 5 DPC n = 4, 4, 5, and 9 for WT and 4, 4, 1, and 3 for CRR immunized mice respectively. (F) Viremia of pVD1-WT vaccinated mice increased rapidly 3–5 days after DENV-2 S221 challenge, whereas pVD1-CRR vaccinated mice had 30-fold, 40-fold, and at least 1800-fold lower viremia 3, 4, and 5 DPC (all CRR mice <10 FFU/mL) than did WT immunized mice. Virus titers were log10 transformed and the transformed data analyzed by two-way ANOVA (p < 0.0001). Bonferroni post hoc test significance is depicted with asterisks, error bars represent SEM. 3, 4, and 5 DPC n = 4, 5, and 6 for WT and 4, 1, and 3 for CRR immunized mice respectively.