Figure 3.

OVA- and CT-B-specific IgA Ab responses in mucosal secretions were determined by ELISA (A) and numbers of IgA AFC in mucosal tissues by ELISPOT assay (B) following intranasal immunization with OVA combined with mCT S61F or nCT as mucosal adjuvants. Groups of C57BL/6 mice were immunized with 100 μg of OVA alone (□) or together with 5 μg of rCT-B (▨), 0.5 μg of nCT (░⃞), or 5 μg of mCT S61F (▪) on days 0, 7, and 14. Tissue samples and external secretions were taken 1 week after the last immunization. Bars represent the mean Ab titer or numbers of AFC ± 1 SE in each group. Each group contained five mice and the data are representative of three separate experiments.