Fig. 4.

Immune responses and protection in peptide immunized mice.

Mice were immunized i.n. with pools of 2–3 15-mer peptides covering the 85A_99–118, 85A_70–78 and 85A_145–152 or peptide pools covering the whole 85A sequence from which the 85A_99–118 or 85A_145–152 sequences had been removed, as indicated on the x axis. 4 weeks after the last immunization the proportion of lung (A) and spleen (B) CD4 and CD8 lymphocytes producing IFNγ was determined by intracellular cytokine staining after 6 h stimulation with the 85A_99–118 and 85A_145–152 peptides. Cells from 3_–4 mice were assayed separately. Error bars show SD. Similarly immunized mice were challenged with Mtb five weeks after the last immunization and lung and spleen CFU enumerated (C). Data from one of two experiments with 5 mice/group are shown. ***p < 0.001, **p < 0.01 compared to naïve animals, one-way ANOVA with Tukey's post test.