FIG. 6.

Effect of lipid X on foam cell formation by C. pneumoniae-infected (A) and cLPS-exposed (B) macrophages. (A) Uninfected (open circles) or infected (MOI = 2; closed circles) cells were washed and incubated with 100 μg of LDL per ml for 20 h in the presence or absence of various concentrations of lipid X. (B) Untreated (open circles) or cLPS-treated (100 ng/ml; closed circles) cells were incubated with 100 μg of LDL per ml for 20 h in the presence or absence of various concentrations of lipid X. Macrophages were fixed and stained with oil red O, and about 500 cells were counted from each well. Data are representative of three experiments and are reported as means of triplicates with SD. ∗, statistically significant difference compared with untreated samples, P < 0.005.