A synthetic peptide based on the NS1 non-structural protein of tick-borne encephalitis virus induces a protective immune response against fatal encephalitis in an experimental animal model

Linear immunogenic peptides corresponding to amino acid sequences from the NS1 non-structural protein from tick-borne encephalitis virus (strain Sophyin) were predicted using established algorithms and synthesized. Of the 12 peptides predicted, 11 were able to induce peptide-specific antibodies in BALB/c mice but only 1 of these 11 was able to induce antibodies, which reacted with the native protein in a radio-immune precipitation assay. This peptide corresponds to amino acids 37–55, and forms one of the predicted structurally conserved alpha helices of the virus NS1 protein. It was able to protect 60% of animals against lethal challenge with the homologous highly pathogenic tick-borne encephalitis virus strain, and adoptive transfer experiments indicated the involvement of the antibodies induced by this peptide in its protective activity in mice.