Gliadins resist complete gastrointestinal digestion, leaving immunologically relevant peptides intact. While gliadin peptides have been reported to induce innate immune responses in intestinal epithelial cells, their transcriptomic effects in celiac disease and healthy control induced pluripotent stem cell-derived small intestinal epithelial cells (iPSC-SIECs) remain unclear.
Celiac and healthy control iPSC-SIECs were exposed for 4 h and 24 h to peptic-tryptic digests of commercial wheat gliadin, wheat gliadins from pure line of hexaploid bread wheat (BW208) and tetraploid durum wheat (Don Pedro), and their CRISPR-Cas9-edited wheat lines (V653 and V520, respectively) and maize zein. Transcriptomic responses were analysed using RNA sequencing, differential expression analysis (DESeq2), and pathway enrichment analyses.
Expression of intestinal epithelial marker genes confirmed successful differentiation into iPSC-SIECs. No major transcriptomic differences were detected between gliadin- and zein-treated cells in either celiac or healthy control lines. Compared with zein, gliadin treatments modestly upregulated genes associated with vesicular trafficking, microtubule-based processes, and membrane transport. No alteration in immune-related pathways was observed.
Gliadins alone induced limited transcriptional responses in iPSC-SIECs, affecting mainly membrane transport-related functions without triggering immune activation. These findings suggest that additional factors are required for the development of gliadin-induced immune responses characteristic of celiac disease. The model provides a useful platform for studying epithelial responses to dietary proteins.