A new generation needle- and adjuvant-free trivalent plague vaccine utilizing adenovirus-5 nanoparticle platform

摘要

Female Swiss–webster mice (n = 13/group) were immunized (i.n.) with either 1 or 2 doses (21 days apart) of rAd5-YFV vaccine (1.2 × 1010 v.p.), and animals administered PBS served as controls (a). Vaccination scheme is depicted in panel b. Twenty-four days after the final vaccination, eight mice from each group were i.n. challenged with 100 LD50 (5 × 104 CFU/40 µL) of Y. pestis CO92-lux, and the survival of animals plotted (c). P values were calculated using Kaplan–Meier analysis with log-rank (Mantel–Cox) test for animal survival. Spleens were harvested from the five remaining unchallenged mice in each group and splenocytes stimulated with PMA and Ionomycin. Brefeldin A was added to prevent secretion of cytokines. Splenocytes were then stained for T-cell surface markers CD3, CD4, and CD8, followed by intracellular IFNγ staining. Percent of CD4+ IFNγ+ (d) and CD8+ IFNγ+ (e) T cells were analyzed by flow cytometry and the data expressed as the arithmetic means ± standard deviations. P values were calculated using a one-way ANOVA with Tukey post-hoc test to compare multiple groups or student t-test to compare 1 dose of rAd5-YFV vaccine to control in panel e. Asterisks above columns represent comparison to the control group, while horizontal bars represent differences between test groups. *P < 0.05, **P < 0.01, ****P < 0.0001. Two biological replicates were performed, and data plotted.