Figure 3
B3-PDDV induced the highest antibody response. (A) Analysis of B-PDDV-induced antibody responses. Seven days after the last immunization with B-PDDVs, 18K-PDDV, or PBS, mouse whole IgG, IgG1, and IgG2a antibody responses to SWA (0.1 mg/ml) were analyzed by ELISA. Data are expressed as the mean ± SD (n = 6 per group) of 18 mice from three independent experiments performed in triplicate wells. ** P < 0.01 and *** P < 0.001, compared to the 18K-PDDV and PBS groups. (B) Splenocyte proliferation assay. Splenocytes (2 × 105/well) from each mouse were incubated in triplicate wells for three days in 200 μl of media in 96-well plates in the presence of B1-, B2-, B3-18K fusion peptide, or 18K (10 μg/ml) peptides (or media alone). Proliferation was determined by measuring [3H] thymidine incorporation for the last 16 h of the experiment. Data are expressed as the mean ± SD (n = 6 per group) of 18 mice from three independent experiments. * P < 0.05. (C-D) Cytokine production analysis. Supernatants were collected after 48 h of culture and examined for IFN-γ (C) or IL-4 (D). Bars show the mean ± SD (n = 6 per group) of 18 mice from three independent experiments performed in triplicate wells.