Figure 2.

Lymphocyte activation occurs in co-cultures using either live or dead BCG. PBMCs from healthy donors were incubated with the indicated BCG substrains. The ratio was calculated to mimic the amount of total bacteria in the commercial vaccine, 6:1 ratio (total bacteria to PBMC) from cultures either 100% viable, 50% viable or completely inactivated by 20 min at 100°C. At day 7, cells in suspension were recovered from the co-culture, centrifuged and analyzed by flow cytometry. (A) The percentage of activation was determined by identifying the resting and activating lymphocyte regions by FSC vs SSC. The percentage of activated lymphocytes was plotted for each donor (different colors) and viability condition. Statistical analysis was performed using one-way ANOVA comparing each condition with the untreated culture (*p < 0.05; **p < 0.01; ns, non-significant). (B) The percentage of the CD56^bright population was obtained within the NK cell region for each donor and analyzed as in (A).