Infection with M. bovis BCG (pAS-MDP1) caused a lesser activation of PBMC than infection with BCG (pMV261), as is evident from the cytokine expression of infected PBMC: 24 hours after infection the pro-inflammatory cytokine IL1-β was secreted at significantly lower amounts upon infection with the antisense-strain (Figure 3). This evidence concerns the gene IL1B and infection.