Gag p24 formulated with CAF05 induces antigen-specific CD4 and CD8 T-cell responses in CB6F1 mice.

<p>Mice were immunized three times i.p. with 20 µg Gag p24 protein alone (open triangles) or adjuvanted in CAF01 (black circles) or CAF05 (open circles). Naïve mice were used as a negative control (black triangles). The T-cell response in spleens was determined three weeks after the last immunization by restimulation <i>in vitro</i> with either whole Gag p24 protein (A), the CD8 T-cell epitope AMQMLKETI-containing peptides 16–17 (B) or 10 µg/ml of a mix of overlapping Gag p24 peptides (C-D). T-cell responses were assessed by ELISA to determine the release of IFN-γ in supernatants after 4 days (A-B) or flow cytometry to determine the percentage of IFN-γ⁺ CD44^hi cells of the total CD4 (grey bars) or CD8 (black bars) T cell population (C) and the percentage of cells expressing both IFN- γ, TNF-a and IL-2 after 8 hours of stimulation (D). (A-D) Each data point represents the mean (n = 6) +/− SEM. Where the CAF05 adjuvant induced a statistically significantly higher response than CAF01 determined by two-way ANOVA and the Bonferroni post test, this has been indicated: *<i>p<</i>0.05, ***<i>p<</i>0.001. (E) The percentage of AMQMLKETI-specific CD44^hi cells of the total CD8 T-cell population was also determined in blood pooled within each group 1 week after the last vaccination.