Fig. 2
PGA/Alum-adjuvanted OVA-immunized aged mice showed increases in OVA-specific CD8+ T cell activation and IgG production. Aged mice (n = 4–5 per group) were i.m. administered OVA protein alone or combined with γ-PGA, alum, or PGA/Alum on days 0, 14, and 21. Seven days after the last immunization, the splenocytes and sera were obtained from the mice. A IFN-γ+ SFUs were enumerated via ELISPOT assays after stimulating splenocytes with OVA257–264 for 60 h. B Flow cytometry was performed by stimulating splenocytes with OVA257–264 in the presence of monensin for 12 h, followed by staining with a fluorescent dye-conjugated anti-CD3ε and anti-CD8α Abs and by further intracellular staining with an anti-IFN-γ-PE Ab. C The splenocytes were stained with a fluorescent dye-conjugated anti-CD8α Ab and H-2Kb-OVA257–264 tetramer and then analyzed within CD8+ T cell via flow cytometry. D–F ELISA was performed using sera to determine Ab titers of OVA-specific IgG (D), IgG1 (E), and IgG2b (F). Statistical significance was analyzed using one-way ANOVA/Bonferroni; *P < 0.05, **P < 0.01, and ***P < 0.001