Fig 5.

DCP enhances iNOS expression in monocytes infected with BCG. (A) Uninfected or BCG-infected human monocytes (∼1.5 × 10⁵ cells/well or ∼10% of the initial PBMC numbers = high monocyte density), enriched from PBMCs through overnight plastic adherence, were cultured with or without DCP at 37°C. After 12 h of culture, total cellular RNA was isolated and iNOS mRNA expression measured by quantitative RT-PCR. Data shown are means ± standard errors of the means of fold increases in iNOS expression in monocytes obtained from 6 different volunteers. Significant differences in mean iNOS mRNA were detected in the following comparisons: uninfected without DCP versus uninfected with DCP (**, P = 0.0050), uninfected with DCP versus BCG infected with DCP (*, P = 0.0260), and BCG infected without DCP versus BCG infected with DCP (**, P = 0.0022). (B) Direct evidence that DCP induces NO production in M. bovis BCG-infected murine BMDMϕ (*, P = 0.031). (C) Effects of addition of anti-MIP-1β on iNOS induction in BCG-infected cells treated with DCP or not (*, P = 0.0158). Rab, rabbit control antibody. P values were obtained by using the Mann-Whitney U test (A), Wilcoxon signed-rank test (B), and paired Student t test (C).