FIGURE 7.

PA-specific Abs after intranasal immunization with wt PA and EF mutants. A, PA-specific serum Ab isotype and IgG subclass responses after intranasal administration of EdTx derivatives. Mice were immunized three times at weekly intervals with 2 µg PA alone; 2 µg PA plus 2 µg EF; or 2 µg PA-U7 plus 2 µg EF-K346R. The IgA and IgG subclass (IgG1 and IgG2a) Ab responses were determined 1 wk after the last immunization. B, PA-specific Ab levels in mucosal secretions (saliva and vaginal washes) were assessed 2 wk after the last immunization. The results are expressed as the reciprocal log₂ titers ± 1 SD and are from three experiments and five mice/group. Statistical significance: *p ≤ 0.05 when compared with mice immunized with PA only.