Interaction of Helicobacter Pylori TRX1 with Gastric Epithelial Cells

Thioredoxins (Trx) are ubiquitous thiol disulfide reductases that have multifunctional roles in different cell types, including redox regulation of transcription factor activation. Helicobacter pylori contains two thioredoxins (Trx1, Trx2) and, unusually, both species are secreted by the bacterium in vitro. As components of the bacterial secretome these proteins may have a role to play in host-pathogen interactions.

Aims: The aim of this study was to evaluate the interaction of H. pylori Trx1 with gastric epithelial cells (AGS) and to examine its subcellular distribution within these cells

Methods: AGS cells were treated with recombinant H. pylori Trx1. Immunofluorescent staining and confocal microscopy was performed. Membrane fractions were treated with Trx1 and a probe which identifies Trx1-reduced proteins

Results: The interaction of Trx1 with membrane constituents of AGS cells was verified. Trx1-reduced proteins in the membrane fraction of AGS cells were also identified by SDS-PAGE analysis. Furthermore, confocal studies indicated that Trx1 remained membrane bound over time, indicating that the interaction may not be redox-mediated.

Conclusion: The interaction of Trx1 with AGS cells provides a mechanism whereby H. pylori Trx1 may modulate AGS cell surface protein expression and intracellular signalling events as demonstrated previously by its ability to modulate NFkB expression.