Key Points
- To investigate whether antibody-mediated poliovirus neutralization and associated virion conformational changes depend on bivalent antibody binding under nonsaturating conditions.
- Treated neutralizing antibody-poliovirus complexes under nonsaturating conditions with papain to cleave antibodies into monovalent fragments.
- Administered secondary anti-immunoglobulin G (anti-IgG) antibodies to restore antibody cross-linking.
- Monitored viral neutralization efficacy and conformational alterations via shifts in the isoelectric point (pI) of the virion across various antibody types, including VP3-specific antibodies.
- Papain cleavage of bound antibodies resulted in the loss of viral neutralization and reversed the neutralization-associated shift in virion pI.
- Addition of anti-IgG antibodies restored both poliovirus neutralization and the alteration in viral pI.
- Monospecific neutralizing antibodies targeting capsid protein VP3 served as an exception, retaining neutralizing ability without requiring bivalent attachment.
Structured PICO
PPopulationneutralizing antibody-poliovirus complexes
IInterventionpapain treatment and subsequent treatment with anti-immunoglobulin G antibodies
OOutcomeviral neutralization and change in the isoelectric point (pI) of the virion
Bivalent attachment of antibodies is generally required for poliovirus neutralization and conformational alteration under nonsaturating conditions.