(A) J774A.1 macrophages were pretreated for 30 min with 10 mM MCD to deplete cholesterol, or were pretreated for 30 min with 10 mM MCD followed by addition of 1 mM cholesterol for an additional 30 min. The MCD- and MCD/cholesterol-pretreated macrophages, as well as cells pretreated with medium only, were subsequently incubated with P. gingivalis (MOI=10:1) for the indicated time points. (B) Similar intracellular survival assay, which was modified to ensure comparable numbers of starting intracellular bacteria in MCD-treated and control cells, by using a MOI of 80:1 for MCD-treated cells (the inset confirms similar uptake at 30-min postinfection, determined by the flow cytometric uptake assay). The persistence of viable internalized bacteria was determined using an antibiotic protection-based survival assay. Data are means ± SD (n = 3) from typical experiments performed three (A) or two (B) times yielding similar findings. Asterisks indicate significantly (p < 0.05) reduced recovery of viable CFU from MCD-treated compared to MCD-untreated or cholesterol-reconstituted cells.