Fig. 8
BCG85C5 vaccine induces a robust protection against rechallenge of tuberculosis in mice through expansion of effector (TEM) and central memory (TCM) T cells. a, b CFU counts of Mtb in the lungs and spleens after rechallenge (day 120). BCG85C5 reduces Mtb CFUs in the lung and spleens of mice after rechallenge better than wt-BCG. P-values and log10 difference of CFUs indicated (footnote; n = 5 mice per group; two-way ANOVA). c, d BCG85C5 induces both TEM and TCM T cells in the lungs and spleens after rechallenge (*p < 0.01; **p < 0.009; ***p < 0.007; one-way ANOVA). BCG85C5 induces more CD62L+ CD8 central memory T cells in the lungs and spleens compared with BCG85CFP and wt-BCG (Fig. 7c, p boxes a–c; Fig. 7c, p boxes a, b). wt-BCG induced more CD62L− CD4 effectors in the spleen (Fig. 7d). e CD8 T cells of organs were typed for TB10.4 tetramer-specific CD8 T cells and those expressing granzyme-B and perforin (three individual mice analyzed, and percent positive T cells averaged; *p < 0.0091; one-way ANOVA). BCG85C5 increases numbers of TB10.4+ CD8 T cells in the lungs and spleens correlating with an increase in expression of granzyme-B and perforin. f CD8 T cell pools purified from lungs and spleens were overlaid on Mtb infected macrophages for bactericidal activity as in Fig. 7i. BCG85C5 induced CD8 T cells show enhanced killing of intracellular Mtb (*p < 0.008; one-way ANOVA). P-values determined using one- or two-way ANOVA with Dunnett’s post-test
