A Novel Gastric Spheroid Co-culture Model Reveals Chemokine-Dependent Recruitment of Human Dendritic Cells to the Gastric Epithelium

Abstract

Background & Aims Gastric dendritic cells (DCs) control the adaptive response to infection with Helicobacter pylori , a major risk factor for peptic ulcer disease and gastric cancer. We hypothesize that DC interactions with the gastric epithelium position gastric DCs for uptake of luminal H pylori and promote DC responses to epithelial-derived mediators. The aim of this study was to determine whether the gastric epithelium actively recruits DCs using a novel co-culture model of human gastric epithelial spheroids and monocyte-derived DCs. Methods Spheroid cultures of primary gastric epithelial cells were infected with H pylori by microinjection. Co-cultures were established by adding human monocyte-derived DCs to the spheroid cultures and were analyzed for DC recruitment and antigen uptake by confocal microscopy. Protein array, gene expression polymerase chain reaction array, and chemotaxis assays were used to identify epithelial-derived chemotactic factors that attract DCs. Data from the co-culture model were confirmed using human gastric tissue samples. Results Human monocyte-derived DCs co-cultured with gastric spheroids spontaneously migrated to the gastric epithelium, established tight interactions with the epithelial cells, and phagocytosed luminally applied H pylori . DC recruitment was increased upon H pylori infection of the spheroids and involved the activity of multiple chemokines including CXCL1, CXCL16, CXCL17, and CCL20. Enhanced chemokine expression and DC recruitment to the gastric epithelium also was observed in H pylori –infected human gastric tissue samples. Conclusions Our results indicate that the gastric epithelium actively recruits DCs for immunosurveillance and pathogen sampling through chemokine-dependent mechanisms, with increased recruitment upon active H pylori infection.

Gastrointestinal tract modeling using organoids engineered with cellular and microbiota niches

“…In a mouse model of infection, DCs were recruited to the gastric epithelium, where they interacted directly with H. pylori 55 . Similar findings were recapitulated using a gastric organoid model, where monocyte-derived DCs were found to migrate to and interact with uninfected gastric epithelial organoids, and their migration was increased during H. pylori infection 56 . This augmented recruitment of DCs was shown to be caused by multiple chemokines derived from infected gastric organoids, while the recruited DCs played a role in the phagocytosis of H. pylori, similar to what occurs in gastric mucosa in vivo.…”

Dendritic cell‐derived TGF‐β mediates the induction of mucosal regulatory T‐cell response to Helicobacter infection essential for maintenance of immune tolerance in mice

“…DCs are recruited to the gastric epithelium during H. pylori infection 21,24,39 . These antigen‐presenting cells can migrate from the peripheral tissue to the draining lymph node or spleen with the captured antigen, where they present the antigen to naïve T cells and initiate host immunity 40 .…”

Three-Dimensional Explant Platform for Studies on Choroid Plexus Epithelium

“…The bright field and fluorescence images at 488 nm throughout the explant volume were taken every 2 min during the first 4 h. Alternatively, a time-lapse was recorded during 24 h in a wide-field microscope and the explants were examined after the time-lapse under a confocal microscope to evaluate the number of transmigrating cells. The immune cells in similar experiments have been shown to display activity for 48 h in our earlier studies (Sebrell et al, 2019). Each explant was imaged as a z-stack and every plane was examined to ensure the location of immune cells.…”