PRIMING AND INDUCTION OF ANTIROTAVIRUS ANTIBODY-RESPONSE BY SYNTHETICPEPTIDES DERIVED FROM VP7 AND VP4

Synthetic peptides derived from bovine rotavirus C-486 (BRV) outer cap sid (VP7 and VP4) and inner capsid (VP6) proteins were tested to evalu ate their ability to prime and induce an anti-rotavirus antibody respo nse. Peptides corresponding to the amino acid residues 232-255 of VP4 (VP4-peptide), 275-295 of VP7 (VP7-peptide) and 40-60 of VP6 (VP6-pept ide) of BRV were chemically synthesized, These peptides were coupled t o carrier proteins (either keyhole limpet haemocyanin (KLH) or recombi nant rotavirus inner capsid protein-VP6 assembled into virus-like part icles (VP6-carrier) were used as carrier to link the synthetic peptide s under study), and the resulting conjugates were used to immunize rot avirus seronegative mice. An enzyme-linked immunosorbent assay (ELISA) was used to determine anti-peptide and anti-rotavirus antibody titres in serum samples collected after immunization. All peptides were immu nogenic in mice and induced the production of anti-peptide antibodies, but with the exception of VP6-peptide they were not able to induce an ti-rotavirus antibodies as measured by ELISA. Western blot analysis in dicated that antibodies against each peptide were able to react with t he respective authentic viral proteins of various rotavirus serotypes. To determine if a peptide-primed animal would respond to native viral proteins, animals were subsequently injected with purified BRV. A rap id and high anti-rotavirus antibody titre, in addition to a rise in an ti-peptide antibody titre, was observed in peptide-primed mice. Furthe rmore, the sera obrained from these mice neutralized the virus under i n vitro conditions. The significance of these results in relation to a potential rotavirus synthetic peptide-based vaccine is discussed.