Development of a novel organoid-based two-dimensional system to model the intestinal host-parasite interface in fasciolosis.

BACKGROUND

The earliest interactions between Fasciola hepatica newly excysted juveniles (FhNEJ) and the intestinal epithelium remain poorly understood, partly due to the limited availability of physiologically relevant in vitro models. Here, we establish a human duodenum organoid-derived epithelial monolayer (ODM) co-culture system to investigate the early host-parasite interface, providing a controlled experimental platform for analysing interactions between FhNEJ and the intestinal epithelium.

METHODS

ODMs representing the human duodenum were co-cultured with either live FhNEJ or a tegument-enriched protein fraction derived from the parasites. The ODM co-culture system was subsequently employed to assess FhNEJ viability and parasite-epithelial interactions together with complementary functional and molecular read-outs. These included measurements of trans-epithelial electrical resistance, fluorescein permeability assays, immunofluorescence analysis of intercellular epithelial junctions, and quantitative proteomic profiling.

RESULTS

The ODM-FhNEJ co-culture system supported sustained parasite viability and enabled direct visualisation of intimate parasite-epithelial interactions. Functional and structural analyses revealed epithelial barrier dysfunction upon exposure to FhNEJ, whilst quantitative proteomics generated an exploratory molecular dataset identifying candidate proteins associated with epithelial junction organisation, immune signalling, cellular stress, and mechanotransduction.

CONCLUSION

Together, these findings establish human intestinal ODMs as a physiologically relevant experimental platform for investigating the earliest stages of F. hepatica infection. By integrating functional, imaging-based and quantitative proteomic analyses within a single experimental framework, this model provides a valuable resource for generating and testing hypotheses regarding host-parasite interactions during early-stage fasciolosis.