FIG. 5.

Functional role of B7 for the adjuvant activity of FljB for plasma IgG responses to SBR following mucosal immunization. BALB/c wt, B7-1, B7-2, and B7-1/2 ko mice were immunized via the i.n. route on days 0 and 18 with 20 μg SBR coadministered with 5 μg FljB. BALB/c wt mice immunized with 20 μg SBR only on days 0 and 18 served as controls. SBR-specific plasma IgG, IgG1, IgG2a, and IgG2b responses were analyzed 2 weeks following the second immunization. Results represent the arithmetic mean ± SEM of six mice per group. ** and *** indicate significant differences between the wt and the other groups of mice at P < 0.01 and P < 0.001, respectively.