Binding of Norwalk Virus-Like Particles to ABH Histo-Blood Group Antigens Is Blocked by Antisera from Infected Human Volunteers or Experimentally Vaccinated Mice

specific ABH histo-blood group antigens was investigated by using human saliva and synthetic biotinylated carbohydrates. The three distinct Norwalk-like viruses (NLVs) have various capacities for binding ABH histo-blood group antigens, suggesting that different mechanisms for NLV attachment likely exist. Importantly, antisera from NV-infected human volunteers, as well as from mice inoculated with packaged Venezuelan equine encephalitis virus replicons expressing NV VLPs, blocked the ability of NV VLPs to bind synthetic H type 1, Leb, and H type 3, suggesting a potential mechanism for antibody-mediated neutralization of NV. Norwalk-like viruses (NLVs) are members of the family Caliciviridae and are a leading cause of acute gastroenteritis worldwide. Studies into the basic biology of NLVs have been limited to recombinant molecular approaches and human chal-lenge studies, primarily because no tissue culture model is available and because an animal model for NLV infection has only recently been reported (21). The genome of Norwalk virus (NV), the prototype NLV, is a single-stranded, positive-polar-ity RNA of approximately 7.5 kb in length and is organized int