Single-Dose Mucosal Immunization with a Candidate Universal Influenza Vaccine Provides Rapid Protection from Virulent H5N1, H3N2 and H1N1 Viruses
Figure 2
Immune responses after single-dose rAd immunization.
BALB/cAnNCr mice were immunized with 5×109 particles each of A/NP-rAd and M2-rAd, or 1×1010 particles of B/NP-rAd i.n. or i.m., or were unimmunized (naïve). Analyses were performed at one month (A, C, E, G) or 10 months (B, D, F, H) post-immunization. (A, B) M2e-specific IgG (left panels) and IgA (right panels) responses in serum and BAL were measured by ELISA as described. Bars show mean ± SEM of 3 mice per group. The dashed line indicates limit of detection. (C, D) Pro-inflammatory cytokine levels in BAL were measured as described. Bars show mean ± SEM of 4 mice per group at 1 month or 3 mice per group at 10 months. T-cell responses in spleen (E, F) and lung (G, H) were measured by IFN-γ ELISPOT of triplicate wells after stimulation with NP147–155, Hex486–494, Dbp413–421, M2e2–24, NP55–69 peptides. Unstimulated cells (no peptide) were used as controls. Bars show mean total IFN-γ secreting cell number per organ ± SEM of 4 mice per group at month or 3 mice per group at 10 months. Statistically significant differences are indicated as follows: * P<0.05 compared to all other groups; ‡ P<0.05 compared to i.m. and naïve groups; † P<0.05 compared to i.n. and naïve groups; ** P<0.05 compared to B/NP-rAd and naïve groups; § P<0.05 compared to A/NP+M2-rAd i.n. and naïve groups; # P<0.05 compared to all other groups except A/NP+M2-rAd i.m.