Figure 4.
Antigen-specific cytokine-producing cells stimulated by β-Gal co-formulated with different adjuvants. The quantity of β-Gal-specific cytokine-producing splenocytes was determined by ELISpot assay. IFN-γ (A) IL-2 (B), IL-4 (C), and IL-17 (D) were investigated as indicator cytokines for Th1, Th2, and Th17 biased immune responses. Results obtained restimulating with the TPHPARIGL peptide reflect the number of IFN-γ producing CD8+ T cells while restimulation with β-Gal protein activates CD4+ and by cross-presentation also CD8+ T cells. Results are presented as mean spot-forming units per 106 cells above the background values of unstimulated cells. The SD were calculated from triplicates of two cell concentrations each of control, antigen alone, co-administered with c-di-AMP, alum or adjuvant system c-di-AMP/alum. Statistically significant differences with respect to Control (x), β-Gal alone (*), β-Gal with alum (o) or β-Gal with c-di-AMP (+) were validated by one-way ANOVA with Tukey's post hoc test, with p < 0.05 (*), p < 0.01 (**), p < 0.001 (***), and p < 0.0001 (****).