The molecular mechanisms behind
infection and propagation of human restricted pathogens such as human norovirus (HuNoV) have defied interrogation because they were previously unculturable. However, human intestinal enteroids (HIEs) have emerged to offer unique ex vivo models for targeted studies of intestinal biology, including inflammatory and
infectious diseases.
Carbohydrate-dependent histo-
blood group antigens (HBGAs) are known to be critical for clinical
infection. To explore whether HBGAs of
glycosphingolipids contribute to HuNoV
infection, we obtained HIE cultures established from stem cells isolated from jejunal biopsies of six individuals with different ABO, Lewis, and secretor genotypes. We analyzed their glycerolipid and
sphingolipid compositions and quantified interaction kinetics and the affinity of HuNoV virus-like particles (VLPs) to
lipid vesicles produced from the individual HIE-
lipid extracts. All HIEs had a similar
lipid and glycerolipid composition.
Sphingolipids included HBGA-related type 1 chain
glycosphingolipids (GSLs), with HBGA
epitopes corresponding to the geno- and phenotypes of the different HIEs. As revealed by single-particle interaction studies of Sydney GII.4 VLPs with
glycosphingolipid-containing HIE membranes, both binding kinetics and affinities explain the patterns of susceptibility toward GII.4
infection for individual HIEs. This is the first time norovirus VLPs have been shown to interact specifically with secretor gene-dependent GSLs embedded in
lipid membranes of HIEs that propagate GII.4 HuNoV ex vivo, highlighting the potential of HIEs for advanced future studies of intestinal glycobiology and host-pathogen interactions.