Figure 2
T3-PDDV induced both cellular and humoral immune responses. (A) T-PDDV induced cellular immunity. Seven days after the last immunization with T-PDDVs, 18K-PDDV, or PBS, splenocytes were harvested and antigen-specific proliferation was measured. Splenocytes (2 × 105/well) from each mouse were incubated in triplicate for three days in 200 μl in 96-well plates in the presence of either the T2-18K, T3-18K, or 18K peptides (10 μg/ml), or media alone. To each well 0.5 μCi [3H] thymidine was added 16 h before the end of the incubation period. Data are expressed as the mean ± SD (n = 6 per group) of 18 mice from three independent experiments performed in triplicate wells. *** P < 0.001. (B-C) Cytokine production following T2- or T3-PDDV vaccinations. IFN-γ (B) and IL-4 (C) production was measured in splenocytes harvested and cultured from the respective vaccination groups for 48 h. Bars show the mean ± SD (n = 6 per group) of 18 mice from three independent experiments performed in triplicate wells. * P < 0.05; *** P < 0.001. (D) IgG, IgG1, and IgG2a responses in immunized mice. Antibody responses to SWA (0.1 mg/ml) were determined by ELISA. *** P < 0.001, compared with 18K-PDDV and PBS groups. Data are expressed as the mean ± SD (n = 6 per group) of 18 mice from three independent experiments performed in triplicate wells.