EFFECTIVE INDUCTION OF NEUTRALIZING ANTIBODIES WITH THE AMINO-TERMINUS OF VP2 OF CANINE PARVOVIRUS AS A SYNTHETIC PEPTIDE

Fourteen synthetic peptides corresponding to previously wrapped antige nic sites in VP2 of canine parvovirus (CPV) were used for immunization of rabbits to identify antiviral properties favourable for inclusion into a vaccine. Most antipeptide antisera obtained were reactive with viral protein, and with one of them it was possible to locate the hypo thetical amino terminus of VP3 within positions 15-31 of VP2. Virus-ne utralizing antibodies were only obtained with two overlapping 15-mer p eptides corresponding in sequence to the amino terminus of VP2 (MSDGAV QPDGGQPAVRNERAT). Antibodies in the neutralizing sera bound most stron gly to amino acids of the sequence DGGQPAV within the N-terminus of VP 2, indicating that efforts to develop a synthetic vaccine against CVP should be focused on this stretch of amino acids. The two peptides ind uced long-lasting immunity (at least 8 months) using either Freund's a djuvant or aluminium hydroxide plus Quil A. Thus, this approach deline ated the exact peptide sequence useful for vaccines applied to the ami no-terminal region of VP2. These findings in experimental animals form a solid basis for exploration of a synthetic peptide vaccine against parvovirus infection in dogs, minks or cats.