FIG. 1.
L. monocytogenes invasion of Caco-2 monolayers. (A) Caco-2 cells, Caco-2/MDR cells, or Caco-2 cells treated with MRK16 (final concentration, 10 μg/ml) were incubated with 108, 107, 106, and 105 L. monocytogenes EGD organisms, and invasion was measured after 1 h (n = 6 per condition). Caco-2/MDR cells were less susceptible and MRK16-treated cells were more susceptible to L. monocytogenes invasion. *, P < 0.05 compared to untreated Caco-2 cells. (B) An isotype control antibody had no effect on invasion (n = 3 per condition). Data are means plus SD. (C) Real-time PCR results confirming no difference in E-cadherin mRNA expression between Caco-2 and Caco-2/MDR cell lines (P > 0.05). The relative concentration of E-cadherin mRNA was normalized to GAPDH mRNA levels. Values are means plus SD from duplicate experiments.