Recognition of synthetic peptides with sequences of rubella virus E1 polypeptide by antibodies and T lymphocytes

Antigenicity of rubella virus E1 polypeptide was analyzed using synthetic peptides with predicted amino acid sequences. Overlapping solid-phase bound peptides were used to define antibody binding domains and a panel of free peptides to study T-cell responsiveness. Several antibody-binding areas including those earlier described to contain major neutralizing epitopes were recognized by human sera positive for rubella antibodies. T-cell lines specific for rubella virus were established from 14 rubella immune subjects. All cell lines responded to rubella virion-derived antigen but only eight (57%) responded to one or more of the synthetic peptides. Individual patterns of peptide recognition were found but peptide 8 representing amino acids 402-422 was most often stimulatory to T-cells lines, either alone (3 subjects) or in combination with peptide 3 (amino acids 245-269) or 3 and 4 (amino acids 269-287). The response was HLA restricted but no single DR specificity for this restriction was identified.