Dual roles of host N-glycosylation in enteropathogenic Escherichia coli infection.

Host factors determine pathogen tropism but knowledge of host genes facilitating enteropathogenic Escherichia coli (EPEC) infection is limited. To identify host determinants required for infection by EPEC, we performed two independent genome-scale CRISPR-Cas9 screens. Both converged on host N-glycosylation as a critical requirement for infection. Genetic or pharmacological inhibition of N-glycan maturation revealed that N-glycosylation promotes infection through two distinct pathways. First, N-linked poly-N-acetyllactosamine glycans serve as receptors for the major EPEC adhesin, the bundle-forming pilus (BFP). Second, perturbation of N-glycosylation compromises host membrane structure, resulting in reduced type III secretion system activity, independently of host cell attachment. Using epithelial monolayers derived from human colon and jejunum organoids, we further show that EPEC attachment inversely correlates with terminal mannose exposure, suggesting glycan composition may be involved in determining intestinal tropism. Together, these findings establish host N-glycan maturation as a key host pathway exploited during enteric infection.