C57BL/6 mice were vaccinated three times (50 µg each, s.c.) with IL-17A-VLP, IL-17F-VLP, either reagents or unconjugated control VLPs. A–C) αIL-17A and αIL-17F titers were analyzed two weeks after the last immunization by ELISA and compared to unconjugated-VLP immunized controls (B,C; OD450 nm values +/− SEM). D,E) Neutralization was tested by ELISA. D) ELISA plates were coated with 1 µg/ml IL-17RA and binding of 10 ng/ml biotinylated IL-17A to IL-17RA was tested in the presence of serum of mice immunized with IL-17A-VLPs, IL-17F-VLPs or VLPs alone (OD450 nm values +/− SEM). E) ELISA plates were coated with 1 µg/ml IL-17RC and binding of 200 ng/ml biotinylated IL-17F to IL-17RC was tested in the presence of serum of mice immunized with IL-17A-VLPs, IL-17F-VLPs or VLPs alone; OD450 nm values +/− SEM. F–J) Subsequent analysis in S. Typhimurium challenge infections. Animals were pretreated with streptomycin and infected for 2 days with wt S. Typhimurium. PBS immunization and PBS treatment served as control. We analyzed colonization levels in the gut lumen (F), the mLN (G), the liver (H) and the spleen (I), as well as the degree of inflammation of the cecum mucosa (J). Comparison with the control VLPs immunized mice did not reveal any significant differences in any of the parameters of the infection, analyzed (J: Mann-Whitney U test was not significant as well as ANOVA with Bonferroni (p = 0.0841)). Stippled line: minimal detectable value.