IL-8 mRNA expression in GES-1 cells stimulated with PBS, LPS and recombinant CagL protein. GES-1 and LPS, PBS, different concentrations of recombinant CagL were cultured for 4 h, respectively. M DNA Marker DL2000, 1 Positive control (GES-1 cells co-cultured with LPS), 2 GES-1 cells co-cultured with PBS, 3 GES-1 cells co-cultured with the extractive of bacterium transformed with PET28a(+), 4–9 GES-1 cells co-cultured with different concentrations of recombinant CagL (1, 5, 10, 15, 20 and 30 μg/ml)