Immature DC Activation by BCG and rBCG-hIL-18

Immature DCs at a density of 1 × 10⁶ cells/mL were incubated for 24 h at 37 °C and 5% CO₂ with live BCG or rBCG-hIL-18 at a multiplicity of infection of 1, according our previously established protocol [18 (link)]. Der p 1, kindly provided by G.A. Stewart (University of Western Australia) and Joël Pestel (Institut Pasteur de Lille), was used at 1 μg/mL [18 (link),19 (link)]. This concentration had previously been determined as being optimal for the induction of Th-2 cytokines in allergic patients [17 (link)]. As positive maturation controls, DCs were stimulated with 1 μg/mL LPS (Escherichia coli LPS O55:B5, Sigma-Aldrich Chemical), while DCs in medium alone represented the negative controls. Supernatants of the cultures were tested by ELISA (Eli-pair Diaclone test) for the presence of IL-10, IL-12p70 and IL-23 (detection sensitivity: 5 pg/mL for IL-10 and IL-12p70; 20 pg/mL for IL-23), IP-10 (CXCL10) (R&D systems; detection sensitivity: 5 pg/mL), TARC (CCL17) and MDC (CCL22) (R&D systems; detection sensitivity: 10 pg/mL).