Fig 2.

DCP inhibits intracellular mycobacterial growth in monocytes grown at lower densities. PBMCs from 6 different volunteers were plated at a density of 1.5 × 10⁵ cells per well in a 96-well plate and incubated overnight at 37°C in a 5% CO₂ incubator. After overnight incubation, nonadherent cells were washed off, and the enriched monocytes (∼1.5 × 10⁴ cells/well or ∼10% of the initial PBMC numbers = low monocyte density) were cultured for one more day before infection with BCG at a multiplicity of infection of 0.3 bacteria/cell. Extracellular (nonphagocytosed) bacilli were washed off, and infected cells were treated with 1,600 μM DCP for 72 h. Data shown are percent inhibition of intracellular M. bovis BCG growth derived from two separate experiments: experiment 1 (A) and experiment 2 (B). P values were obtained by using Mann-Whitney U tests.