FIGURE 4.

IL-17 splenocyte recall response to PA in IL6-ko, CD80/86, CD40, TLR2, and TLR4 mutant mice. All mice were immunized intranasally with PA-NE, PA in PBS, or NE alone. Splenocytes were obtained at 10 to 12 weeks after primary immunization. Representative results from two experiments are presented as -fold of IL-17 cytokine induction in antigen-stimulated splenocytes over nonstimulated cultures (± SEM). Antigen-specific IL-17 expression was analyzed in a wild-type C57BL/6 and compared with IL6-ko mice (A). A statistically significant difference in IL-17 expression was detected between wild-type and IL6-ko mice, p value = 0.0305. B, CD86, double CD80/CD86, and CD40 mutant mice were analyzed for the response to PA. Statistically significant differences in IL-17 expression were detected after nasal PA-NE immunization, as wild-type animals produced significantly more IL-17 than either CD80/CD86 or DC40 mutant mice with p values of 0.006 and 0.006, respectively. No statistical difference was detected between wild-type and the single CD86 mutants (p = 0.0502). C, TLR2 and TLR4 mutant mice show differences in IL-17 expression, as wild-type mice produced much greater amounts of IL-17 after NE immunization than TLR mutant mice, with p values of 0.0278 and 0.0249 for TLR2 and TLR4, respectively. No statistical difference was detected in the PA-alum and the NE groups (C, data not shown for A and B).