Fig 7.
DCP activity against M. tuberculosis H37Rv. PBMCs were plated at a density of 1.5 × 106 cells per well in round-bottom 96-well plates and incubated overnight at 37°C. After 2 h of incubation, nonadherent cells were washed off, and the enriched monocytes (∼1.5 × 105 cells/well or ∼10% of the initial PBMC numbers = high monocyte density) were cultured for one more day before infection with M. tuberculosis H37Rv (Mtb-H37Rv) at a multiplicity of infection of 3 bacteria/cell. Extracellular (nonphogocytosed) bacilli were washed off, and infected cells were treated with 1,600 μM DCP for 72 h, after which cultures were lysed and residual bacteria quantitated by determination of uptake of tritiated uridine and CFU counts. Data shown are percent inhibition of intracellular mycobacterial growth calculated from uptake of tritiated uridine (A) and CFU counts (B). Each black square or circle represents an individual volunteer. P values were obtained by Wilcoxon signed-rank tests.