FIG 4.

Anti-Listeria activity of PLA2G2A in IL-22-treated HepG2 cells. (A) HepG2 cells were incubated in the presence or absence of rPLA2G2A (left) or rLCN2 (right) before L. monocytogenes infection. The infected cells were then incubated for 1 h, extracellular bacteria were killed by addition of gentamicin, and the samples were incubated for 3 h more. Intracellular bacterial number was analyzed after the culture. (B) HepG2 cells were incubated with IL-22 for 2 days, and culture supernatants were collected. L. monocytogenes was added to control medium or IL-22-conditioned supernatants with or without the PLA2G2A-specific inhibitor LY315920 (LY), mixtures were incubated for 1 h, and bacterial numbers were determined. Bars and error bars represent means and standard deviations. *, P < 0.001 compared to the untreated control. The data are representative of at least two independent experiments with four to six samples.