Characterization of high affinity IgM and IgG monoclonal antibodies against norovirus variants GII.4 and GII.17

Abstract

Human norovirus, a leading cause of viral gastroenteritis, results in significant global health and economic burden, requiring sensitive and accurate diagnosis and effective therapeutics and vaccines. In this study, we immunized mice with the virus like capsid particles of GII.4, a mainstream strain, and GII.17, a modern strain that began to circulate in 2014, and used hybridoma technology to generate hybridoma cells that produce norovirus-binding antibodies against GII.4 and GII.17, respectively. Selection of these hybridoma cells yielded monoclonal IgG and IgM antibodies against these strains. Characterization of these antibodies revealed that avidity effect by multivalent binding is necessary for IgM to bind to norovirus at high efficiency, while IgG achieve high affinity even by monovalent binding. Surface plasmon resonance and ELISA data suggest that the high density of antigen protrusion domain in the norovirus capsid, containing approximately protomers, facilitates IgM to bind to norovirus capsid with high efficiency.