Antigen presenting cells from aged mice do not upregulate MHC class II expression in response to vaccine components <i>in vitro</i>.

<p>Bone marrow derived macrophages (BMM) or dendritic cells (BMDC) from young adult (6–8 weeks, dark bars) and aged (18–24 months, light bars) were stimulated <i>in vitro</i> with CpG, Fluzone (FZ) or both (FZ+CpG) overnight. Up regulation of MHC class II relative to unstimulated cells (media) was measured using flow cytometry on (A) BMM (F4/80+/CD11b+) and (C) BMDC (CD11c+/CD11b^med /F4/80-). TNF-α production was measured by ELISA in supernatants from (B) BMM and (D) BMDC. Readings were taken as an average of triplicate wells. Results shown are mean values + S.D and are representative of 2 independent experiments.</p

Heme agglutination inhibition and Influenza-specific IgG titers in sera of immunized mice.

<p>Heme agglutination inhibition and Influenza-specific IgG titers in sera of immunized mice.</p

Single Fluzone vaccination with or without adjuvants is non-protective in aged mice.

<p>Young adult (6–8 weeks) and aged (18–24 months) C57/BL6 mice (n = 5–8 mice per group) were vaccinated with Fluzone (FZ), Fluzone+CpG (FZ+CpG) or left unvaccinated as controls. Approximately 4 weeks later, all groups were challenged with 1x10⁴ p.f.u of A/California/09 H1N1 virus. Weight loss (A) and (C) and survival (B) and (D) were monitored daily in young adult and aged mice respectively. Individual data points represent average weight loss within the group of surviving mice +/-SEM.</p

Protection in immunized young adult mice is associated with improved cellular immunity and reduced viral titers.

<p>Young adult mice (6–8 weeks) vaccinated twice, 2 weeks apart, with Fluzone (FZ x2), Fluzone+CpG (FZ+CpG) and unvaccinated controls were challenged with 1x10⁴ p.f.u of A/California/09 H1N1. Five mice per group were sacrificed at day 7 post-infection. (A) The frequency of neutrophils (CD3-/Ly6C+) and (B) CD3+/CD8+ T-cells was measured by flow cytometry in homogenates of the right lobe of the lung. Dots represent individual mice and horizontal lines represent average +/-SEM where *p<0.05. (C) Lung virus titers from pooled mice (n = 5 per group) were determined day 7 post challenge using homogenates from the left lobe of the lung. Equal volumes of lung homogenate were pooled from 5 mice in each group and the horizontal bar represents average of duplicate wells. Data shown is representative of 2 independent experiments.</p