Engineering of cell line assembled enteric organoid for enterovirus infection

The non-polio-enteroviruses are ubiquitous pathogens infecting over a billion people in the world. An alarming number of enterovirus-associated acute flaccid paralysis, encephalitis, hand, foot, and mouth disease, conjunctivitis and diarrhoea cases are reported worldwide. Despite their clinical significance, vaccine development has been hindered due to lack of suitable in vitro models for preclinical investigations. The present study was undertaken to develop a cell line assembled organotypic model of human intestine for replication of enteroviruses. An enterovirus specific PSGL1 receptor was introduced in intestinal epithelial HCT-8 cell line employing CRISPR/cas9 gene editing. It was co-cultured with human colon (CCD-18) and endothelial (HUVEC) cell lines with peripheral blood mononuclear cells in hanging drops and rotating wall vessel bioreactor to yield three-dimensional organoids. Histological analysis of the organoids showed presence of columnar epithelium cells with prominent intracytoplasmic mucin, hyperchromatic nuclei and presence of CK, CK20, MUC 2 and Villin markers characteristic of epithelial cells. Infection with Enterovirus A71 (EV-A71) demonstrated significantly higher viral titre in organoids compared to individual cell lines. Collectively, these findings determine, for the first time, a cell line-derived enteric organoid model that supports robust enterovirus replication, offering a cost-effective and physiologically relevant system for virology research and preclinical applications.