Fig 4.

DCP enhances MIP-1β production by mycobacterium-infected monocytes. Monocytes, enriched from PBMCs through plastic adherence (∼1.5 × 10⁴ cells/well or ∼10% of the initial PBMC numbers), were infected overnight with BCG (MOI = 0.3). Extracellular bacteria were gently washed off, and BCG-infected cells were treated with 1,600 μM DCP for 72 h at 37°C. After 72 h of culture, supernatants were collected and quantities of IP-10 (A; P = 0.0043), MIG (B; P = 0.0022), CCL5 (C; P = 0.9372), MIP-1α (D; P = 0.1823), and MIP-1β (E; P = 0.0313) were measured using CBA. (F) DCP-mediated inhibition of intracellular BCG was reversed with 10 μg/ml human anti-MIP-1β (*, P = 0.0151; **, P = 0.0022). (G and H) Additional experiments showed that anti-MIP-1β can reverse DCP-mediated inhibition of BCG by both tritiated-uridine uptake (G) and CFU (H) endpoints, but anti-MIP-1β had no effects on BCG-infected monocytes not treated with DCP (*, P = 0.0159; **, P = 0.0079). Data shown are means ± standard errors of the means of results obtained with monocytes from 6 different volunteers (A to F) and 5 different volunteers (G and H). P values were obtained by using Mann-Whitney U tests.