RT Journal Article SR Electronic(1) A1 Pelicic, Vladimir A1 Reyrat, Jean-Marc A1 Sartori, Lucia A1 Pagliaccia, Cristina A1 Rappuoli, Rino A1 Telford, John L. A1 Montecucco, Cesare A1 Papini, EmanueleYR 1999 T1 Helicobacter pylori VacA cytotoxin associated with the bacteria increases epithelial permeability independently of its vacuolating activity JF Microbiology, VO 145 IS 8 SP 2043 OP 2050 DO https://doi.org/10.1099/13500872-145-8-2043 PB Microbiology Society, SN 1465-2080, AB Polarized epithelial monolayers of Madin-Darby canine kidney (MDCK) cells were used to study the pathogenicity of Helicobacter pylori, with an emphasis on the effect of VacA. The adherence of H. pylori to MDCK monolayers resulted in a decrease in trans-epithelial resistance (TER) across the cell monolayer. Isogenic vacA mutants did not lower the TER, demonstrating that the effect is strictly linked to the action of the toxin. A similar effect was observed with all VacA-producing strains, including those producing m2 toxins that are inactive in the vacuolating assay. In contrast to that seen with purified toxin, TER decrease was not enhanced by acid pH, which may indicate that the toxin associated to the bacterial surface is possibly in a monomeric state and therefore does not require a pH-induced conformation to be active. These data raise the possibility that one role of VacA in ulcerogenesis may consist of increasing the paracellular permeability of the gastric epithelium., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-145-8-2043