Figure 5.

BCG vaccination in humans induces MAV and MAB cross-reactive T cells. Paired pre-and post-vaccination PBMC from recently BCG vaccinated volunteers living in St. Louis, MO (n = 5) were used. PBMC were labeled with CFSE and stimulated with BCG, MAB WL, or MAB WL. Medium rested PBMC were used as negative controls. On day 7, cells were restimulated with PMA/ionomycin for 2 h, viable cells were counted and cells were stained for surface and intracellular markers for flow cytometry study. (A–C) show the data for proliferating and IFN-γ producing T cells. (D–F) show the data for proliferating and GZM-A producing T cells. There were significantly higher absolute numbers (AN, per ml of cultures) of BCG-reactive CFSE^loIFN-γ⁺CD4⁺ T cells (P = 0.03, Wilcoxon Matched Pairs test), MAV WL reactive CFSE^loIFN-γ⁺CD4⁺ T cells (P = 0.03), MAV WL reactive CFSE^loIFN-γ⁺CD8⁺ T cells (P = 0.03), MAV WL reactive CFSE^loGranzyme A⁺CD8⁺ T cells (P = 0.03), MAB WL reactive CFSE^loIFN-γ⁺CD4⁺ T cells (P = 0.03), and MAB WL reactive CFSE^loGranzyme A⁺CD4⁺ T cells (P = 0.03), indicating that BCG induces NTM cross-reactive immunity. *P < 0.05.