Co-application of pC191 inhibited the effective boosting of HBsAg-specific immune response.

<p>BALB/c mice (n = 6 for each group) were immunized three times by in vivo electroporation with different doses of the plasmids pCI, pHBsAg, pC191, or combinations as indicated in (A). Sera of immunized mice were collected on 10th days after the third immunization, serially diluted, and tested by ELISA assay. (B) Total HBsAb IgG responses. (C) HBsAb IgG subclasses IgG1 and IgG2a. (D) Ratios of HBsAb IgG2a/IgG1. (E) Splenocytes were collected from mice at day 10 after the third immunization and subjected to ELISPOT assay. Splenocytes were re-stimulated with a HBsAg peptide (H-2L^d CTL epitope aa 29–38). HBsAg specific IFN-producing cells were determined by identified by spot formation. The numbers represent the means of spot-forming cells per 2×10⁵ splenocytes. The error bars represent the standard deviation. Statistically significant differences between the groups are displayed as *(p<0.05) or **(p<0.01).