Figure 6

Survival of Mtb-infected animals was associated with enhanced CD8⁺ CTL responses and reduced Mtb antigen load, particularly at the site of infection in the lung. Immune responses induced in TB lung lesion and spleen of the S = survival group as compared with the D = deceased group. The different prime-boost regimens are indicated in red (rBCG/rAd35), blue (BCG/rAd35) and green (unvaccinated control) symbols. Animals in the survival group (n = 10) remained alive until the end of the trial (wks 23–24), whereas animals in the deceased group (n = 8) died from their TB disease during the course of the trial (wks 10–18). Lung biopsies from one rBCG/rAd35- and one BCG/rAd35-vaccinated NHP are missing and thus the number of animals in the survival group is lower in lung compared with spleen. The median protein expression of Mtb antigen (MPT64), immune cells (CD68, CD20, CD3, CD8 and CD4) and effector molecules (IL-7, perforin and granulysin) are presented as percent positive area of the total cell area. Statistical significance of differences in protein expression was determined by a non-parametric Kruskal-Wallis test.