FIG.5.

MRP2 expression is upregulated in response to EAEC 042 infection and plays a key role in regulating 042-induced PMN transepithelial migration. A: Following apical infection with EAEC 042, the apical side of polarized T84 cell monolayers was coated with biotin and the cells were then lysed and biotin-coated proteins immunoprecipated with streptavidin-beads (see Experimental procedures). HBSS⁺-treated cells served as a negative control (-). 25 μg protein samples were separated on gradient polyacrylamide gels and immunoblotted using an MRP2 antibody diluted 1:500. B: T84 monolayers were pretreated with the MRP2 inhibitor probenecid for 24 hours and assessed for effect on 042-induced PMN transepithelial migration. fMLP was included as a positive control. C: Monolayers of HCT-8 cells transfected with a vector control or a vector modified to generate siRNAs aimed at decreasing the expression of MRP2 were assessed for their effect on EAEC 042- or E. coli F-18-induced PMN transepithelial migration. The data are expressed as the mean ± SD for triplicate samples and represent one of at least three independent experiments performed with similar results. ***, p < 0.001; **, p < 0.01.