FIG 5 .
Granuloma-like structures from LTBI individuals produce more robust inflammatory cytokines. PBMCs obtained from LTBI and naive individuals were infected with M. tuberculosis H37Rv (MOI 1:1) for up to 12 days, and cytokine levels in cell culture supernatants collected at several time points after infection were determined by ELISA. Naive individuals, light grey bars; LTBI individuals, dark grey bars. Uninfected cells were used as controls. ND, not detected. n = 3 (in triplicate). *, P < 0.05; **, P < 0.01; ***, P < 0.001 (by t test).