BCG vaccination in adults enhances perforin production by γδ T cells. (A) Schematic representation of the experimental setup for γδ T-cell characterization in BCG-vaccinated volunteers. (B) Flow cytometry analysis of CD3⁺TCRγδ⁺ T cells among CD45⁺ cells in peripheral blood of unvaccinated controls and BCG-vaccinated volunteers before (week 0) vaccination and 2 wk (week 2) and 3 mo (week 12) after vaccination; gated CD45⁺ cells. (C) Cumulative percentages of CD3⁺TCRγδ⁺ T cells assessed as in B. (D) Representative flow cytometry dot plots. (E) cumulative percentages of perforin-producing γδ T cells (nonvaccinated controls, n = 2; BCG vaccinated, n = 15).