FIG 4.

AZ-521 cells express Cx43 and are more susceptible to VacA than are cell lines that do not express Cx43. (A) Cx43 expression in AZ-521, HeLa, AGS, and RK13 cells was evaluated by Western blotting using an anti-Cx43 antibody. Production of GAPDH was monitored to ensure equal loading. (B to E) AZ-521, HeLa, AGS, and RK13 cells were incubated with serial dilutions of H. pylori broth culture supernatants containing WT VacA or VacA-G14A (an inactive mutant protein) for 24 h, and cell viability was determined by the ATPlite assay. AZ-521 cells were the most susceptible to VacA-induced killing. Error bars represent means plus standard errors from combined results of three independent experiments, each performed in triplicate.