Figure 3.

Long-term immunization with IL-17.1 maintained immune memory without an autologous anti-IL17.1 T-cell response. (A) Mice were maintained for 1 year after the final immunization before blood collection and a subsequent boost, with the exception of one mouse that died of unrelated causes at 50 weeks. Final sera were collected at week 58 and mice were sacrificed for analysis of T cell response by ELISpot. (B) Anti-IL17.1 responses had declined by 1 year but rebounded after being recalled (unrelated antigen (OVA) responses included as a negative control). The difference was measurable although not statistically significantly different (ns, p = 0.1411) (C) Splenocytes were left unstimulated or stimulated with IL17.1 peptide, PADRE peptide, or Concanavalin A and demonstrated a significant IL-4 response against PADRE but no significant response against IL17.1. (D) Neither IL17.1 nor PADRE elicited a significant IFN-γ response. n = 4, statistical differences for antibody responses were calculated by paired t-test, while statistical differences for the ELISpot assay were calculated by one-way ANOVA and Tukey's test for multiple comparisons. **p < 0.01, ***p < 0.001. Data are presented as Mean ± SD.