Fig. 4

Mucosal adjuvant activity of CpG ODN-loaded DOTAP/DC-chol liposomes assessed by the induction of OVA-specific nasal IgA and serum IgG in BALB/c mice. BALB/c female mice were immunized intranasally with PBS, OVA (5 µg/mouse) alone, OVA (5 µg/mouse) plus DOTAP/DC-chol liposomes, OVA (5 µg/mouse) plus CpG ODN (1 µg/mouse), or OVA (5 µg/mouse) plus CpG ODN-loaded DOTAP/DC-chol liposomes on days 0 and 7. Serum and nasal washes were collected on day 14. The anti-OVA IgA level in nasal washes and anti-OVA IgG, IgG1, and IgG2a levels in serum were detected by ELISA assay as described in the “Methods” section. The data were obtained from three independent experiments. The box-plot shows the median value with the 25th–75th percentiles and the error bars indicate the 5th–95th percentiles. The symbols in box plots represent individual mice (PBS, n = 10; OVA, n = 10; OVA plus liposome, n = 10; OVA plus CpG-loaded liposome, n = 12). Significance was assessed using the Kruskal–Wallis with Dunn’s post–hoc test: *p < 0.05, NS not significant