Cytokine secretion by human PBMC. Human PBMC were infected with BCG (pMV261) and BCG (pAS-MDP1) at an MOI of 1, and the amount of IL-1β (A), IFN-γ (B), TNF-α (C) and IL-10 (D) in the supernatants was quantified by ELISA 24 hours after infection. The values were referred to the amount of cytokines induced by BCG (pMV261), which were set to 100%. The columns represent the mean of at least five independent experiments (different donors) with the standard deviation. The results of an unpaired student’s t test showing the significance of different expressions in PBMC infected with BCG (pMV261) and BCG (pAS-MDP1) are represented by asterisks (**: P < 0.01).