FIG 2 .
Granuloma-like structure formation is accelerated in cells from individuals with LTBI. (a) PBMCs obtained from LTBI and naive individuals were infected with M. tuberculosis H37Rv (MOI 1:1) for up to 12 days. While naive individuals typically demonstrated no evidence of cell aggregation until day 6 postinfection, on average, the LTBI cell cultures exhibited phase 3 to 4. (b) The scoring system was applied on day 7 postinfection, and 15 high-power fields/sample were evaluated. Naive individuals, light grey bars; LTBI individuals, dark grey bars. All images are ×40. Uninfected cells were used as controls. n = 12 in triplicate. ***, P < 0.001 (by t test). M.tb, M. tuberculosis.