Fig 3. PLGA vaccination induces systemic antigen-specific cytokine responses.

Frequency of cytokine-producing CD4⁺ T-lymphocytes in the spleens of mice immunised (A) i.n and (B) s.c with TDB adjuvanted vaccines, and (C) s.c with MPL adjuvanted vaccines, as assessed at four weeks following final immunisation. Antigen-specific cells were detected by intra-cellular immunostaining and flow cytometry after recall with MPT83 (10 μg/ml) for 12 hr followed by addition of Brefeldin A and further incubation for 4 hr. Data are the means ± SEM (n = 3) and are representative of two independent experiments. Statistically significant differences were determined by ANOVA with post-hoc Bonferroni comparison to adjuvant only control (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).