Fig 6. Rv2882c boosting enhanced the BCG protective immune response in an in vivo model.

The infection procedure is described in the Materials and Methods. Six weeks after challenge, animals’ spleens and lungs were harvested and the number of bacteria (CFUs) per organ was counted. (A) Schedule for BCG immunization, Rv2882c boosting, and Mtb challenge. (B) Bacterial loads in the lungs and spleens of each group are represented as the mean (± SEM) log₁₀ CFUs/organ (n = 5); *p < 0.05; **p < 0.01; ***P < 0.001 vs. the infection-only group. (C) Spleen and lung cells were harvested from mice in each group, and the cytokine levels were analyzed by ELISA. The lung and spleen cells (10⁶/well) were treated with Ag85B (10 μg/mL) or Rv2882c (10 μg/mL) for 3 days. These cells were obtained from each group of vaccinated mice. The data are shown as mean ± SD (n = 15); *p < 0.05, **p < 0.01, or ***p < 0.001: a significant difference between Rv2882c- or Ag85B-restimulated nonvaccination and vaccination groups, as determined by one-way ANOVA. Treatments without significant effects are labeled with n.s.