Localization of the virus neutralizing and hemagglutinin epitopes of E1 glycoprotein of rubella virus

Chaye, Helena; Chong, Pele; Tripet, Brian; Brush, Brad; Gillam, Shirley

Abstract Current serological assays using whole rubella virus (RV) as a target antigen for detecting RV-specific antibodies fail to define specific RV proteins and antigenic determinants such as hemagglutinin (HA) and virus-neutralizing (VN) epitopes of rubella virus. A panel of El deletion mutants and a subset of E1-specific monoclonal antibodies (MAb) were used for the initial analysis of HA and VN epitopes of E1 glycoprotein. A peptide region (E1193 to E1269.) was found to contain HA and VN epitopes. Using both overlapping synthetic peptides and truncated fusion proteins within this region, the HA epitope defined by MAb 3D9F mapped to amino acid residues El214 to El240, while two VN epitopes defined by MAb 211391-1 and MAb 16A1 OE mapped to amino acid residues El 214 to E1233 and E1219 to E1233, respectively. The epitopes defined in this study are recognized by antibody whether or not the epitopes are glycosylated.