Transcriptome analysis reveals significant discrepancies between two in vitro models of host-trematode interaction

Cell models emulating an in vitro parasitic infection can greatly improve our understanding of helminthiases. Nonetheless, it remains challenging to select an appropriate in vitro model to study molecular pathogenesis of infections by trematodes having a complex life cycle. Therefore, adequate models are in high demand. The epidemiologically important foodborne trematode Opisthorchis felineus parasitizes bile ducts of fish-eating mammals, including humans. The human infection leads to chronic inflammation and biliary intraepithelial neoplasia, which is considered precancerous. This study was aimed at evaluating two useful in vitro research tools based on human cholangiocytes' (H69 cells') response to the trematode: coculture with live worms or incubation with parasite-derived excretory-secretory products (ESPs). We assessed H69 cells' proliferation, migration rate, cell cycle shift, and cytokine production. We also conducted genome-wide transcriptome analysis to identify affected cascades of regulatory signaling events. We demonstrated significant discrepancies between the two in vitro models of host-parasite interactions. Although differences between the two models in cell proliferation and cell migration rate were weak, there were substantial differences in the production and release of cytokines IL-6, IL-4, and TNF. A total of 144 genes in H69 cells were found to be differentially expressed after coculture with live worms, whereas 537 genes were differentially expressed after exposure to ESPs. Transcriptomic analysis revealed only 11 common upregulated genes and six common downregulated genes. Functional enrichment analysis of the gene sets also revealed some striking differences between the in vitro models. Our data will contribute to a deeper understanding of biliary neoplasia associated with liver fluke infection. This study underscores the importance of choosing an appropriate in vitro model to accurately emulate host-parasite interactions. The data also highlight the need for further investigation into the pathogenesis of the precancerous biliary lesions associated with liver fluke infection.