FIG. 5.

TLR4-dependent induction of inflammatory cytokines by PLY. Peritoneal macrophages from C57BL/6 wt mice (black bars) and TLR4 KO mice (white bars) were stimulated with cholesterol-treated rPLY (A to C) or infected with wt S. pneumoniae at a macrophage/bacterium ratio of 1:10 (D) for 24 h, and the culture supernatants were then collected. The amounts of IL-1α, IL-1β, and IL-18 in culture supernatants were determined by ELISA. The results are representative of three similar experiments. The data are the means ± standard deviations for three determinations. Asterisks indicate that the value is significantly different from that of wt cells (P < 0.05).