Binding of recombinant norovirus like particle to histo-blood group antigen on cells in the lumen of pig duodenum

Histo-blood group antigens (HBGA) expressed on cells in the human GI tract have been shown to function as receptors for noroviruses. In concordance with earlier reports (Backer et al., 1997 and Yamamoto and Yamamoto, 2001), this study found that individual pigs are either HBGA type A positive or type H1 (type O) positive. Recombinant norovirus like particles from a genogroup I (rNVLP) or three genogroup II (rMOH, rVA207, and rVA387) strains bound to plates coated with pig gastro-intestinal washings with similar binding patterns to humans. The binding of human norovirus like particles was inhibited by pre-incubating the wells with MAbs specific for either type A or type H1 HBGA, or by the presence of free HBGAs from human saliva. Co-localization of rNVLP and corresponding HBGA on epithelial cells of pig gastro-intestinal tissue (PGIT) was also observed. These findings suggest that rNVLP binds to HBGAs expressed on PGIT epithelial cells. This is the first report of the specific binding of human rNVLP to HBGAs in epithelial cells of pig gastrointestinal tissue. It highlights the importance of further study of human norovirus incidence and potential infection and residence in non-human animal hosts and suggests the possibility that norovirus may be a zoonotic pathogen.