A collection of patient-derived intestinal organoid lines reveals epithelial phenotypes associated with genetic drivers of pediatric inflammatory bowel disease.

Pediatric Inflammatory Bowel Disease (IBD) is a chronic condition characterized by persistent intestinal inflammation in children and adolescents. Despite a rising global incidence, the underlying causes and optimal management strategies for pediatric IBD are still not fully understood. Compared to adult IBD, pediatric IBD frequently presents with distinct disease phenotypes, and is more commonly linked to rare monogenic variants that cause intestinal epithelial barrier dysfunction or affect the function of mucosal immune cells. While more than 100 genes have been associated with early-onset IBD, the roles of many of these genes in the intestinal epithelium and the mechanisms by which genetic variants contribute to disease remain poorly defined. Here we aimed to improve our understanding of intestinal epithelium dysfunction in early-onset IBD by conducting extensive molecular and cellular characterization to gain insights into patient-specific epithelial phenotypes and identify therapeutic targets. We generated intestinal epithelial organoids (IEOs) from 94 pediatric IBD patients, representing diverse clinical characteristics and including those with monogenic variants (BTK n=4, TTC7A n=3, IL10RA n=1, LRBA n=1, STXBP2 n=1, TTC37 n=1, TRNT1 n=1, PLCG2 n=1, DKC1 n=1, POLA1 n=1), and 46 non-IBD controls. This effort resulted in the largest RNA-seq dataset of pediatric IBD intestinal epithelial organoids to date, encompassing both baseline conditions and post-immunological stimulation, serving as a valuable resource for future research. We observed that IEOs effectively initiate inflammation upon stimulation with bacterial lysate, regardless of disease status, origin, or mutation status. Inflammatory stimulation triggered single-gene upregulation of IBD-linked SERPINA1 and LIFR across the IBD population compared to controls, suggesting their role in intestinal epithelial innate immune responses. However, co-expression network analysis showed no consistent transcriptional signatures across the entire IBD group at the systems level. Instead, differences emerged between controls and specific genotypes (TTC7A, STXBP2, LRBA), with STXBP2 and LRBA sharing an upregulated transcriptional response of IL-1 and SLC30-mediated zinc trafficking pathways. These findings underscore the potential of IEOs as a valuable model for studying IBD and offer key insights that could guide the development of targeted therapies for both monogenic and non-monogenic forms of IBD.