INTRODUCTION

is the dominant species infecting humans, but most advances in developing robust culturing platforms for have utilised . Consequently, there is relatively little available information specific to the biology and life cycle of . The present study utilised a pumpless and tubeless gut-on-chip to generate a physiologically relevant environment by applying a constant fluid shear stress of 0.02 dyn cm to HCT-8 cells.

METHODS

Gut-on-chips were fabricated using standard soft lithography. oocysts isolated from human pathology samples were used to infect the human ileocecal colorectal adenocarcinoma (HCT-8) cell line under a constant fluid shear stress of 0.02 dyn cm. Parasite growth was assessed using a -specific quantitative PCR, a genus-specific immunofluorescence assay, and scanning electron microscopy. Differences in the HCT-8 transcriptome with and without fluid shear stress, and the host-parasite interaction, were both assessed using bulk transcriptomics.

RESULTS

Transcriptomic analysis of the HCT-8 cell line cultured within the gut-on-chip demonstrated a metabolic shift towards oxidative phosphorylation when compared to the same cell line cultured under static conditions. Extended (subtype IdA15G1) cultures were sustained for up to 10 days within the gut-on-chip as shown by a -specific qPCR and a genus-specific immunofluorescence assay, which demonstrated ~30-fold amplification in the gut-on-chip over the duration of the experiment. Scanning electron microscopy of infected monolayers identified trophozoites, meronts, merozoites, macrogamonts, microgamonts, and possible gamont-like stages at 48 h post-infection. The potential role of gamonts in the life cycle remains unclear and warrants further investigation. Transcriptomes of HCT-8 cells infected with revealed upregulation of biological processes associated with cell cycle regulation and cell signalling in -infected cells under fluid shear stress compared to static culture.

CONCLUSIONS

These data demonstrate that bioengineered gut-on-chip models support extended growth and can be used to interrogate responses of host cells to infection. Owing to its relative simplicity, the pumpless and tubeless gut-on-chip can be accessible to most laboratories with established HCT-8 infection models for culture.