Potent neutralization of hepatitis A virus reveals a receptor mimic mechanism and the receptor recognition site.
Wang X., Zhu L., Dang M., Hu Z., Gao Q., Yuan S., Sun Y., Zhang B., Ren J., Kotecha A., Walter TS., Wang J., Fry EE., Stuart DI., Rao Z.
Hepatitis A virus (HAV) infects ∼1.4 million people annually and, although there is a vaccine, there are no licensed therapeutic drugs. HAV is unusually stable (making disinfection problematic) and little is known of how it enters cells and releases its RNA. Here we report a potent HAV-specific monoclonal antibody, R10, which neutralizes HAV infection by blocking attachment to the host cell. High-resolution cryo-EM structures of HAV full and empty particles and of the complex of HAV with R10 Fab reveal the atomic details of antibody binding and point to a receptor recognition site at the pentamer interface. These results, together with our observation that the R10 Fab destabilizes the capsid, suggest the use of a receptor mimic mechanism to neutralize virus infection, providing new opportunities for therapeutic intervention.