Changes of tight junction and interleukin‐8 expression using a human gastroid monolayer model of Helicobacter pylori infection

Abstract

Background Lack of a model that mirrors Helicobacter pylori‐induced gastric mucosal inflammation has hampered investigation of early host‐bacterial interactions. We used an ex vivo model of human stomach, gastric epithelial organoid monolayers (gastroid monolayers) to investigate interactions of H pylori infection and the apical junctional complex and interleukin‐8 (IL‐8) expression. Method Morphology of human antral mucosal gastroid monolayers was evaluated using histology, immunohistochemical (IHC) staining, and transmission electron microscopy (TEM). Functional and gross changes in the apical junctional complexes were assessed using transepithelial electrical resistance (TEER), cytotoxicity assays, and confocal laser scanning microscopy. IL‐8 expression was evaluated by real‐time quantitative PCR and ELISA. Results When evaluated by IHC and TEM, the morphology of gastroid monolayers closely resembled in vivo human stomach. Following inoculation of H pylori, TEER transiently declined (up to 51%) in an H pylori density‐dependent manner. TEER recovered by 48 hours post‐infection and remained normal despite continued presence and replication of H pylori. Confocal scanning microscopy showed minimal disruption of zonula occludens‐1 or E‐cadherin structure. IL‐8 production was unchanged by infection with either CagA‐positive or CagA‐negative H pylori and JNK and MEK inhibitors did not suppress IL‐8 production, whereas p38 and IKK inhibitor significantly did. Conclusion Human gastroid monolayers provide a model for experimental H pylori infection more consistent with in vivo human infections than seen with typical gastric epithelial cell lines. This ex vivo system should lead to better understanding of H pylori host‐pathogen interactions.

Disruption of gastric mucous granule exocytosis by Helicobacter pylori virulence factor CagA

“…8). In consistent with our results, Uotani et al recently demonstrated that H. pylori-infected polarized epithelial cells of human gastroid monolayers largely maintained their normal tight and adherens junctions and TEER, although TEER transiently declined 17 . Furthermore, mucous granule accumulation only occurred beneath the apical plasma membrane and basolateral mis-sorting was not observed in the CagA-expressing cells (Figs.…”

“…For example, interleukin-8 (IL-8), a chemoattractant for neutrophils, is thought to play a major role in the H. pylori-associated in ammatory reaction and the level of IL-8 expression has been reported to depend on CagA in gastric cancer cell lines [14][15][16] . However, a recent report using a human gastric epithelial organoid monolayer (gastroid monolayer) model of H. pylori infection demonstrated that IL-8 production showed no signi cant change by infection with either CagA-positive or CagAnegative H. pylori 17 .…”

Expression of Tight Junction Proteins According to Functional Dyspepsia Subtype and Sex

“…46 A recent ex vivo study using human gastroid monolayers demonstrated declined transepithelial electrical resistance following H. pylori inoculation and minimal disruption of ZO-1 or E-cadherin structure were observed by confocal scanning microscopy. 47 Similar to our previous study, 10 female patients with FD were more anxious and had a more impaired QoL than male patients with FD. Emerging evidence provided by recent epidemiological studies indicates that anxiety or depression and functional GI symptoms were positively associated.…”

Review ‐ Helicobacter, inflammation, immunology and vaccines

“…When cag PAI‐negative clinical isolates were applied to the gastroid monolayers, they also induced high‐level IL‐8 secretion; no response was observed by cell lines. The authors suggested that this culture model models the human gastric mucosa more closely than cell lines 1 …”