Epitopes of the G1 glycoprotein of La Crosse virus form overlapping clusters within a single antigenic site

Abstract

Antigenic sites on the G1 glycoprotein of La Crosse bunyavirus were defined by constructing a panel of neutralizing and nonneutralizing monoclonal antibodies ( F. Gonzalez-Scarano, R. E. Shope, C. H. Calisher, and N. Nathanson (1982), Virology 120, 42–53). To analyze the relationship between the individual epitopes delineated by monoclonal antibodies, 11 neutralizing antibodies were used to select variant viruses. These variant viruses were tested against the panel of anti-G1 protein monoclonal antibodies by neutralization and by ELISA. The neutralization tests assigned the 11 epitopes to five groups, consisting of 6, 2, 1, 1, and 1 epitopes. ELISA tests gave a similar pattern, but also demonstrated interrelationships between four of the five epitope groups, suggesting that there may be a single immunodominant antigenic site on the G1 protein. When eight nonneutralizing anti-G1 monoclonal antibodies were tested in ELISA, they fell into three of the five epitope groups defined by neutralization; there was no evidence of a separate nonneutralizing antigenic site on the G1 protein.