Following incubation with WT VacA, mutant VacA
proteins, 1 M staurosporine, or 30 nM epsilon-toxin, lactate dehydrogenase
(LDH) release was measured using a CytoTox 96 nonradioactive cytotoxicity
assay (Promega) according to the manufacturer’s instructions. Maximum LDH
release was determined following treatment of cells with lysis buffer