Broadly cross-reactive human antibodies that inhibit genogroup I and II noroviruses.
Alvarado, G., Salmen, W., Ettayebi, K., Hu, L., Sankaran, B., Estes, M.K., Venkataram Prasad, B.V., Crowe Jr., J.E.(2021) Nat Commun 12: 4320-4320
- PubMed: 34262046 
- DOI: https://doi.org/10.1038/s41467-021-24649-w
- Primary Citation of Related Structures:  
7JIE - PubMed Abstract: 
The rational development of norovirus vaccine candidates requires a deep understanding of the antigenic diversity and mechanisms of neutralization of the virus. Here, we isolate and characterize a panel of broadly cross-reactive naturally occurring human monoclonal IgMs, IgAs and IgGs reactive with human norovirus (HuNoV) genogroup I or II (GI or GII). We note three binding patterns and identify monoclonal antibodies (mAbs) that neutralize at least one GI or GII HuNoV strain when using a histo-blood group antigen (HBGA) blocking assay. The HBGA blocking assay and a virus neutralization assay using human intestinal enteroids reveal that the GII-specific mAb NORO-320, mediates HBGA blocking and neutralization of multiple GII genotypes. The Fab form of NORO-320 neutralizes GII.4 infection more potently than the mAb, however, does not block HBGA binding. The crystal structure of NORO-320 Fab in complex with GII.4 P-domain shows that the antibody recognizes a highly conserved region in the P-domain distant from the HBGA binding site. Dynamic light scattering analysis of GII.4 virus-like particles with mAb NORO-320 shows severe aggregation, suggesting neutralization is by steric hindrance caused by multivalent cross-linking. Aggregation was not observed with the Fab form of NORO-320, suggesting that this clone also has additional inhibitory features.
Organizational Affiliation: 
Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.