FIG. 3.

Effect of L. monocytogenes proteins on the intracellular accumulation of the P-glycoprotein substrate digoxin. Cells were treated with [³H]digoxin (30 nM); its uptake into Caco-2 cells was measured after 1 h (n = 3 per condition) in the presence and absence of increasing amounts of L. monocytogenes proteins (x axis). L. monocytogenes proteins preferentially compete for P-glycoprotein binding, resulting in increased intracellular accumulation of digoxin. Data are means plus SD. *, P < 0.05 compared to digoxin alone.