Figure 9. BCG revaccination significantly induces Mtb-specific cytokines in PBMC.

Representative flow cytometry plots (upper panel) show total IFN-γ, IL-17A, IL-17F, IL-22,IL-2, and IL-10 cytokine–positive CD4⁺ T cells after in vitro stimulation with BCG at T5 in Group 1 versus Group 3 subjects. The flow cytometry plots for the same donors from Groups 1 and 3 for BCG stimulation are shown again in Supplemental Figures 4 and 5. Mtb-specific T cell responses in PBMCs from BCG-revaccinated IGRA⁺ and IGRA^– subjects (Groups 1 and 2, n = 10) were compared with unvaccinated control IGRA⁺ and IGRA^– subjects (Groups 3 and 4, n = 10) in a standard ICS assay (lower panels). PBMCs were stimulated with Ag85A or BCG or a pool of LTAg (Rv1733c, Rv1737c, Rv2029, and Rv2628). CD3⁺CD4⁺ T cells were analyzed for intracellular expression of indicated cytokines. Scatter plots show median (range) percentages of total IFN-γ⁺, IL-17A⁺, IL-17F⁺, IL-22⁺, and IL-10⁺ CD4⁺ T cells. Unadjusted P values were calculated with the Mann-Whitney U test, comparing frequencies of cytokine-positive cells between the 2 groups. To correct for multiple testing (Bonferroni method), P values below 0.025 were considered statistically significant.