We observed a significant decrease in cell death and IL-1β and IL-18 release in both unprimed and IFN-γ-primed GBP1−/− THP-1 clones compared to WT THP-1 cells following infection with T4SS+ Lp, but not with T4SS− Lp (Fig. 4A through C). This evidence concerns the gene GBP1 and infection.